-
Notifications
You must be signed in to change notification settings - Fork 0
/
Xamarin Challenge Part 2.html
1049 lines (930 loc) · 70.1 KB
/
Xamarin Challenge Part 2.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html>
<html>
<head>
<title>Xamarin Challenge Part 2</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
/* GitHub stylesheet for MarkdownPad (http://markdownpad.com) */
/* Author: Nicolas Hery - http://nicolashery.com */
/* Version: b13fe65ca28d2e568c6ed5d7f06581183df8f2ff */
/* Source: https://github.com/nicolahery/markdownpad-github */
/* RESET
=============================================================================*/
html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
}
/* BODY
=============================================================================*/
body {
font-family: Helvetica, arial, freesans, clean, sans-serif;
font-size: 14px;
line-height: 1.6;
color: #333;
background-color: #fff;
padding: 20px;
max-width: 960px;
margin: 0 auto;
}
body>*:first-child {
margin-top: 0 !important;
}
body>*:last-child {
margin-bottom: 0 !important;
}
/* BLOCKS
=============================================================================*/
p, blockquote, ul, ol, dl, table, pre {
margin: 15px 0;
}
/* HEADERS
=============================================================================*/
h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
}
h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
font-size: inherit;
}
h1 {
font-size: 28px;
color: #000;
}
h2 {
font-size: 24px;
border-bottom: 1px solid #ccc;
color: #000;
}
h3 {
font-size: 18px;
}
h4 {
font-size: 16px;
}
h5 {
font-size: 14px;
}
h6 {
color: #777;
font-size: 14px;
}
body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
margin-top: 0;
padding-top: 0;
}
a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0;
}
h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
margin-top: 10px;
}
/* LINKS
=============================================================================*/
a {
color: #4183C4;
text-decoration: none;
}
a:hover {
text-decoration: underline;
}
/* LISTS
=============================================================================*/
ul, ol {
padding-left: 30px;
}
ul li > :first-child,
ol li > :first-child,
ul li ul:first-of-type,
ol li ol:first-of-type,
ul li ol:first-of-type,
ol li ul:first-of-type {
margin-top: 0px;
}
ul ul, ul ol, ol ol, ol ul {
margin-bottom: 0;
}
dl {
padding: 0;
}
dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px;
}
dl dt:first-child {
padding: 0;
}
dl dt>:first-child {
margin-top: 0px;
}
dl dt>:last-child {
margin-bottom: 0px;
}
dl dd {
margin: 0 0 15px;
padding: 0 15px;
}
dl dd>:first-child {
margin-top: 0px;
}
dl dd>:last-child {
margin-bottom: 0px;
}
/* CODE
=============================================================================*/
pre, code, tt {
font-size: 12px;
font-family: Consolas, "Liberation Mono", Courier, monospace;
}
code, tt {
margin: 0 0px;
padding: 0px 0px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px;
}
pre>code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent;
}
pre {
background-color: #f8f8f8;
border: 1px solid #ccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px;
}
pre code, pre tt {
background-color: transparent;
border: none;
}
kbd {
-moz-border-bottom-colors: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background-color: #DDDDDD;
background-image: linear-gradient(#F1F1F1, #DDDDDD);
background-repeat: repeat-x;
border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
border-image: none;
border-radius: 2px 2px 2px 2px;
border-style: solid;
border-width: 1px;
font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
line-height: 10px;
padding: 1px 4px;
}
/* QUOTES
=============================================================================*/
blockquote {
border-left: 4px solid #DDD;
padding: 0 15px;
color: #777;
}
blockquote>:first-child {
margin-top: 0px;
}
blockquote>:last-child {
margin-bottom: 0px;
}
/* HORIZONTAL RULES
=============================================================================*/
hr {
clear: both;
margin: 15px 0;
height: 0px;
overflow: hidden;
border: none;
background: transparent;
border-bottom: 4px solid #ddd;
padding: 0;
}
/* TABLES
=============================================================================*/
table th {
font-weight: bold;
}
table th, table td {
border: 1px solid #ccc;
padding: 6px 13px;
}
table tr {
border-top: 1px solid #ccc;
background-color: #fff;
}
table tr:nth-child(2n) {
background-color: #f8f8f8;
}
/* IMAGES
=============================================================================*/
img {
max-width: 100%
}
</style>
<style type="text/css">
.highlight { background: #ffffff; }
.highlight .c { color: #999988; font-style: italic } /* Comment */
.highlight .err { color: #a61717; background-color: #e3d2d2 } /* Error */
.highlight .k { font-weight: bold } /* Keyword */
.highlight .o { font-weight: bold } /* Operator */
.highlight .cm { color: #999988; font-style: italic } /* Comment.Multiline */
.highlight .cp { color: #999999; font-weight: bold } /* Comment.Preproc */
.highlight .c1 { color: #999988; font-style: italic } /* Comment.Single */
.highlight .cs { color: #999999; font-weight: bold; font-style: italic } /* Comment.Special */
.highlight .gd { color: #000000; background-color: #ffdddd } /* Generic.Deleted */
.highlight .gd .x { color: #000000; background-color: #ffaaaa } /* Generic.Deleted.Specific */
.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #999999 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .gi .x { color: #000000; background-color: #aaffaa } /* Generic.Inserted.Specific */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
.highlight .gu { color: #aaaaaa } /* Generic.Subheading */
.highlight .gt { color: #aa0000 } /* Generic.Traceback */
.highlight .kc { font-weight: bold } /* Keyword.Constant */
.highlight .kd { font-weight: bold } /* Keyword.Declaration */
.highlight .kp { font-weight: bold } /* Keyword.Pseudo */
.highlight .kr { font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #445588; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #009999 } /* Literal.Number */
.highlight .s { color: #d14 } /* Literal.String */
.highlight .na { color: #008080 } /* Name.Attribute */
.highlight .nb { color: #0086B3 } /* Name.Builtin */
.highlight .nc { color: #445588; font-weight: bold } /* Name.Class */
.highlight .no { color: #008080 } /* Name.Constant */
.highlight .ni { color: #800080 } /* Name.Entity */
.highlight .ne { color: #990000; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #990000; font-weight: bold } /* Name.Function */
.highlight .nn { color: #555555 } /* Name.Namespace */
.highlight .nt { color: #000080 } /* Name.Tag */
.highlight .nv { color: #008080 } /* Name.Variable */
.highlight .ow { font-weight: bold } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mf { color: #009999 } /* Literal.Number.Float */
.highlight .mh { color: #009999 } /* Literal.Number.Hex */
.highlight .mi { color: #009999 } /* Literal.Number.Integer */
.highlight .mo { color: #009999 } /* Literal.Number.Oct */
.highlight .sb { color: #d14 } /* Literal.String.Backtick */
.highlight .sc { color: #d14 } /* Literal.String.Char */
.highlight .sd { color: #d14 } /* Literal.String.Doc */
.highlight .s2 { color: #d14 } /* Literal.String.Double */
.highlight .se { color: #d14 } /* Literal.String.Escape */
.highlight .sh { color: #d14 } /* Literal.String.Heredoc */
.highlight .si { color: #d14 } /* Literal.String.Interpol */
.highlight .sx { color: #d14 } /* Literal.String.Other */
.highlight .sr { color: #009926 } /* Literal.String.Regex */
.highlight .s1 { color: #d14 } /* Literal.String.Single */
.highlight .ss { color: #990073 } /* Literal.String.Symbol */
.highlight .bp { color: #999999 } /* Name.Builtin.Pseudo */
.highlight .vc { color: #008080 } /* Name.Variable.Class */
.highlight .vg { color: #008080 } /* Name.Variable.Global */
.highlight .vi { color: #008080 } /* Name.Variable.Instance */
.highlight .il { color: #009999 } /* Literal.Number.Integer.Long */
.pl-c {
color: #969896;
}
.pl-c1,.pl-mdh,.pl-mm,.pl-mp,.pl-mr,.pl-s1 .pl-v,.pl-s3,.pl-sc,.pl-sv {
color: #0086b3;
}
.pl-e,.pl-en {
color: #795da3;
}
.pl-s1 .pl-s2,.pl-smi,.pl-smp,.pl-stj,.pl-vo,.pl-vpf {
color: #333;
}
.pl-ent {
color: #63a35c;
}
.pl-k,.pl-s,.pl-st {
color: #a71d5d;
}
.pl-pds,.pl-s1,.pl-s1 .pl-pse .pl-s2,.pl-sr,.pl-sr .pl-cce,.pl-sr .pl-sra,.pl-sr .pl-sre,.pl-src,.pl-v {
color: #df5000;
}
.pl-id {
color: #b52a1d;
}
.pl-ii {
background-color: #b52a1d;
color: #f8f8f8;
}
.pl-sr .pl-cce {
color: #63a35c;
font-weight: bold;
}
.pl-ml {
color: #693a17;
}
.pl-mh,.pl-mh .pl-en,.pl-ms {
color: #1d3e81;
font-weight: bold;
}
.pl-mq {
color: #008080;
}
.pl-mi {
color: #333;
font-style: italic;
}
.pl-mb {
color: #333;
font-weight: bold;
}
.pl-md,.pl-mdhf {
background-color: #ffecec;
color: #bd2c00;
}
.pl-mdht,.pl-mi1 {
background-color: #eaffea;
color: #55a532;
}
.pl-mdr {
color: #795da3;
font-weight: bold;
}
.pl-mo {
color: #1d3e81;
}
.task-list {
padding-left:10px;
margin-bottom:0;
}
.task-list li {
margin-left: 20px;
}
.task-list-item {
list-style-type:none;
padding-left:10px;
}
.task-list-item label {
font-weight:400;
}
.task-list-item.enabled label {
cursor:pointer;
}
.task-list-item+.task-list-item {
margin-top:3px;
}
.task-list-item-checkbox {
display:inline-block;
margin-left:-20px;
margin-right:3px;
vertical-align:1px;
}
</style>
</head>
<body>
<p><a name="HOLTitle"></a></p>
<h1>Xamarin Challenge Part 2</h1>
<hr>
<p><a name="Overview"></a></p>
<h2>Overview</h2>
<p>One of the key challenges in developing mobile applications for multiple devices and platforms is the divergent set of tools, languages, and resources required to develop and maintain features and functionality across a variety of programming languages, APIs, and user-interface paradigms.</p>
<p><a href="https://www.xamarin.com/">Xamarin</a> offers one solution to the problem by allowing apps to be written in C# for iOS, Android, and Windows using a common API based on Microsoft .NET. Xamarin apps are built with native user interface controls. Apps look and act the way a user expects for a given device and platform. Xamarin apps also have access to the full spectrum of functionality exposed by the underlying operating system and device and are compiled into native binaries for performance.</p>
<p><a href="https://www.xamarin.com/forms">Xamarin Forms</a> is a framework included with Xamarin that allows developers to create cross-platform user interfaces by defining those interfaces in XAML. Controls and UI elements declared in XAML render native controls for the host platform, so iOS users see iOS controls and Android users see Android controls. Whereas classic Xamarin apps share code but not UI, Xamarin Forms apps share code <em>and</em> UI and are frequently able to share 95% of their source code across platforms.</p>
<p><a href="https://www.visualstudio.com/vs/">Visual Studio 2017</a> provides seamless support for Xamarin and Xamarin Forms so you can build cutting-edge mobile apps for a variety of platforms using a single set of tools and APIs. In Part 2 of the Xamarin Challenge, you will enhance the CoolBreeze app you built in Part 1 by adding geolocation support so the app can display the weather conditions at your current location. You will also add to the app the ability to display weather forecasts.</p>
<p><a name="Objectives"></a></p>
<h3>Objectives</h3>
<p>In this challenge, you will learn how to:</p>
<ul>
<li>Add geolocation support to a Xamarin Forms app</li>
<li>Add tabbed pages to a Xamarin Forms app</li>
<li>Add toolbar navigation to a Xamarin Forms app</li>
</ul>
<p>Your feedback is important. If you run into issues while working the exercises in this challenge, please contact us at <a href="mailto:[email protected]">[email protected]</a>.</p>
<p><a name="Prerequisites"></a></p>
<h3>Prerequisites</h3>
<p>The following are required to complete this challenge:</p>
<ul>
<li>Completion of Xamarin Challenge Part 1</li>
<li><a href="https://www.visualstudio.com/vs/">Visual Studio Community 2017</a> or higher</li>
<li>Windows 10</li>
</ul>
<p>If you wish to build and run the iOS version of the challenge app, you also have to have a Mac running OS X 10.11 or higher, and both the Mac and the PC running Visual Studio 2017 require further configuration. For details, see <a href="https://developer.xamarin.com/guides/ios/getting_started/installation/windows/">https://developer.xamarin.com/guides/ios/getting_started/installation/windows/</a>.</p>
<hr>
<p><a name="Exercises"></a></p>
<h2>Exercises</h2>
<p>This challenge includes the following exercises:</p>
<ul>
<li><a href="#Exercise1">Exercise 1: Add geolocation support to the app</a></li>
<li><a href="#Exercise2">Exercise 2: Add a tabbed page to the app</a></li>
<li><a href="#Exercise3">Exercise 3: Add toolbar navigation to the app</a></li>
</ul>
<p>Estimated time to complete this challenge: <strong>30</strong> minutes.</p>
<p><a name="Exercise1"></a></p>
<h2>Exercise 1: Add geolocation support to the app</h2>
<p>Virtually all mobile platforms feature geolocation support, which allows apps to determine the user's current location and even track that location as the user moves. Xamarin doesn't provide a device-independent geolocation API that apps can call upon, but there are free plugins that do. In this exercise, you will import a popular Xamarin plugin that allows any app running on any device to determine the user's location, and then use that plugin to implement a helper method that returns the current location.</p>
<ol>
<li>
<p>Open the <strong>CoolBreeze</strong> solution that you completed in Xamarin Challenge Part 1 in Visual Studio 2017. <strong>If you have not completed Part 1, stop now and complete it before proceeding.</strong></p>
</li>
<li>
<p>In the Solution Explorer, right-click the <strong>CoolBreeze</strong> solution and select <strong>Manage NuGet Packages for Solution...</strong>.</p>
<p><a href="Images/vs-manage-solution-packages.png" target="_blank"><img src="Images/vs-manage-solution-packages.png" alt="Managing NuGet packages for the solution" style="max-width:100%;"></a></p>
<p><em>Managing NuGet packages for the solution</em></p>
</li>
<li>
<p>Ensure that "Browse" is selected in the NuGet Package Manager, and type "Xam.Plugin.Geolocator" (without quotation marks) into the search box. Select the <strong>Xam.Plugin.Geolocator</strong> package. Then check the <strong>Project</strong> box to add the package to all of the projects in the solution, and click <strong>Install</strong>. When prompted to review changes, click <strong>OK</strong>.</p>
<p><a href="Images/vs-install-geolocator.png" target="_blank"><img src="Images/vs-install-geolocator.png" alt="Installing Xam.Plugin.Geolocator" style="max-width:100%;"></a></p>
<p><em>Installing Xam.Plugin.Geolocator</em></p>
</li>
<li>
<p>Review the <strong>readme.txt</strong> file generated by the package installer, making note of the platform-specific manifest requirements for access to location services.</p>
<blockquote>
<p>Although 100% of the code for geolocation in a Xamarin Forms app can be shared across platforms, there are specific permissions that need to be set on a per-platform basis in order for the host operating system to divulge location information. Providing a user's location without permission is considered a violation of privacy.</p>
</blockquote>
<p><a href="Images/vs-nuget-readme.png" target="_blank"><img src="Images/vs-nuget-readme.png" alt="The Xam.Plugin.Geolocator read.me file" style="max-width:100%;"></a></p>
<p><em>The Xam.Plugin.Geolocator readme file</em></p>
</li>
<li>
<p>To enable location services on Android, you need to update the app manifest. Open the <strong>AndroidManifest.xml</strong> file in the <strong>CoolBreeze.Android</strong> project.</p>
<p><a href="Images/vs-select-android-manifest.png" target="_blank"><img src="Images/vs-select-android-manifest.png" alt="Opening the Android app manifest" style="max-width:100%;"></a></p>
<p><em>Opening the Android app manifest</em></p>
</li>
<li>
<p>Add the following statements to the end of the file, right before the closing </manifest> tag:</p>
<div class="highlight highlight-text-xml"><pre><<span class="pl-ent">uses-permission</span> <span class="pl-e">android</span><span class="pl-e">:</span><span class="pl-e">name</span>=<span class="pl-s"><span class="pl-pds">"</span>android.permission.ACCESS_COARSE_LOCATION<span class="pl-pds">"</span></span> />
<<span class="pl-ent">uses-permission</span> <span class="pl-e">android</span><span class="pl-e">:</span><span class="pl-e">name</span>=<span class="pl-s"><span class="pl-pds">"</span>android.permission.ACCESS_FINE_LOCATION<span class="pl-pds">"</span></span> /></pre></div>
<p><a href="Images/vs-updated-android-manifest.png" target="_blank"><img src="Images/vs-updated-android-manifest.png" alt="Updating the Android app manifest" style="max-width:100%;"></a></p>
<p><em>Updating the Android app manifest</em></p>
</li>
<li>
<p>To enable location services on iOS, you need to update the app's information property list. Open the <strong>Info.plist</strong> file in the <strong>CoolBreeze.iOS</strong> project.</p>
<p><a href="Images/vs-ios-plist-file.png" target="_blank"><img src="Images/vs-ios-plist-file.png" alt="Opening the iOS information property list" style="max-width:100%;"></a></p>
<p><em>Opening the iOS information property list</em></p>
</li>
<li>
<p>Scroll to the bottom of the list and click the <strong>+</strong> sign at bottom left to add a new property.</p>
<p><a href="Images/vs-add-ios-property.png" target="_blank"><img src="Images/vs-add-ios-property.png" alt="Adding a property to Info.plist" style="max-width:100%;"></a></p>
<p><em>Adding a property to Info.plist</em></p>
</li>
<li>
<p>From the drop-down list in the "Property" column, select <strong>Location Always Usage Description</strong>. Then add the following text to the "Value" column:</p>
<pre><code>Please allow CoolBreeze to use your current location.
</code></pre>
<p><a href="Images/vs-ios-new-plist-added.png" target="_blank"><img src="Images/vs-ios-new-plist-added.png" alt="Updating Info.plist" style="max-width:100%;"></a></p>
<p><em>Updating Info.plist</em></p>
</li>
<li>
<p>To enable location services on Windows, you need to update the app manifest. Open the <strong>Package.appxmanifest</strong> file in the <strong>CoolBreeze.UWP</strong> project.</p>
<p><a href="Images/vs-uwp-manifest-file.png" target="_blank"><img src="Images/vs-uwp-manifest-file.png" alt="Opening the Windows app manifest" style="max-width:100%;"></a></p>
<p><em>Opening the Windows app manifest</em></p>
</li>
<li>
<p>Click <strong>Capabilities</strong>, and then check the <strong>Location</strong> box.</p>
<p><a href="Images/vs-uwp-capabilities.png" target="_blank"><img src="Images/vs-uwp-capabilities.png" alt="Updating the Windows app manifest" style="max-width:100%;"></a></p>
<p><em>Updating the Windows app manifest</em></p>
</li>
<li>
<p>Now that permissions are set to allow all of the CoolBreeze projects to access location services, it’s time to add code to retrieve location information. In Solution Explorer, right-click the "Helpers" folder in the <strong>CoolBreeze (Portable)</strong> project and use the <strong>Add</strong> > <strong>Class</strong> command to add a class file named "LocationHelper.cs" to the project. Then replace the contents of the file with the following code:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">using</span> <span class="pl-en">System</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Collections.Generic</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Linq</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Text</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Threading.Tasks</span>;
<span class="pl-k">namespace</span> <span class="pl-en">CoolBreeze.Helpers</span>
{
<span class="pl-k">public</span> <span class="pl-k">static</span> <span class="pl-k">class</span> <span class="pl-en">LocationHelper</span>
{
<span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">static</span> <span class="pl-en">Task</span><<span class="pl-en">Plugin</span>.<span class="pl-en">Geolocator</span>.<span class="pl-en">Abstractions</span>.<span class="pl-en">Position</span>> <span class="pl-en">GetCurrentLocationAsync</span>()
{
Plugin.Geolocator.Abstractions.<span class="pl-en">Position</span> <span class="pl-en">location</span> = <span class="pl-k">new</span> <span class="pl-en">Plugin</span>.Geolocator.Abstractions.Position(<span class="pl-k">new</span> <span class="pl-en">Plugin</span>.Geolocator.Abstractions.Position()
{
Latitude = <span class="pl-c1">29.425700</span>,
Longitude = -<span class="pl-c1">98.486110</span>,
});
<span class="pl-k">var</span> <span class="pl-en">geolocator </span>= Plugin.Geolocator.CrossGeolocator.Current;
<span class="pl-k">try</span>
{
geolocator.DesiredAccuracy = <span class="pl-c1">100</span>;
location = <span class="pl-k">await</span> geolocator.GetPositionAsync();
}
<span class="pl-k">catch</span> { }
<span class="pl-k">return</span> location;
}
}
}</pre></div>
</li>
</ol>
<p>The code you just added contains an asynchronous method named <em>GetCurrentLocationAsync</em> that retrieves the user's location, complete with a default location for testing. It, in turn, relies on APIs in Xam.Plugin.Geolocator to retrieve the current location.</p>
<p><a name="Exercise2"></a></p>
<h2>Exercise 2: Add a tabbed page to the app</h2>
<p>Now that location services are enabled on all platforms, it's time to build a user interface around them. In this exercise, you will add a new page for specifying location preferences and add a tabbed page to allow users to easily switch between the page showing location preferences and the page showing current weather conditions.</p>
<ol>
<li>
<p>In Solution Explorer, right-click the <strong>CoolBreeze (Portable)</strong> project and select <strong>Add</strong> > <strong>New Item...</strong>. Then select <strong>Forms Blank Content Page Xaml</strong>, specify "LocationPage.xaml" as the name, and click <strong>Add</strong>.</p>
<p><a href="Images/vs-adding-location-page.png" target="_blank"><img src="Images/vs-adding-location-page.png" alt="Adding a location preferences page" style="max-width:100%;"></a></p>
<p><em>Adding a location preferences page</em></p>
</li>
<li>
<p>Replace the contents of <strong>LocationPage.xaml</strong> with the following XAML:</p>
<div class="highlight highlight-text-xml"><pre><?<span class="pl-ent">xml</span><span class="pl-e"> version</span>=<span class="pl-s"><span class="pl-pds">"</span>1.0<span class="pl-pds">"</span></span><span class="pl-e"> encoding</span>=<span class="pl-s"><span class="pl-pds">"</span>utf-8<span class="pl-pds">"</span></span> ?>
<<span class="pl-ent">ContentPage</span> <span class="pl-e">xmlns</span>=<span class="pl-s"><span class="pl-pds">"</span>http://xamarin.com/schemas/2014/forms<span class="pl-pds">"</span></span>
<span class="pl-e">xmlns</span><span class="pl-e">:</span><span class="pl-e">x</span>=<span class="pl-s"><span class="pl-pds">"</span>http://schemas.microsoft.com/winfx/2009/xaml<span class="pl-pds">"</span></span> <span class="pl-e">Title</span>=<span class="pl-s"><span class="pl-pds">"</span>Location<span class="pl-pds">"</span></span>
<span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">Class</span>=<span class="pl-s"><span class="pl-pds">"</span>CoolBreeze.LocationPage<span class="pl-pds">"</span></span>>
<<span class="pl-ent">StackLayout</span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>20<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Start<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Medium<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>Select the way you want to get weather information. If you select to use your current location, your device may prompt you for permission.<span class="pl-pds">"</span></span>/>
<<span class="pl-ent">StackLayout</span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>0,20,0,0<span class="pl-pds">"</span></span> <span class="pl-e">WidthRequest</span>=<span class="pl-s"><span class="pl-pds">"</span>300<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>CenterAndExpand<span class="pl-pds">"</span></span> <span class="pl-e">Orientation</span>=<span class="pl-s"><span class="pl-pds">"</span>Horizontal<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Medium<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Start<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>Use my current location<span class="pl-pds">"</span></span>/>
<<span class="pl-ent">Switch</span> <span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">Name</span>=<span class="pl-s"><span class="pl-pds">"</span>useLocationToggle<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>End<span class="pl-pds">"</span></span> <span class="pl-e">IsToggled</span>=<span class="pl-s"><span class="pl-pds">"</span>False<span class="pl-pds">"</span></span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>20,0,0,0<span class="pl-pds">"</span></span> <span class="pl-e">Toggled</span>=<span class="pl-s"><span class="pl-pds">"</span>UseLocationToggled<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span>/>
</<span class="pl-ent">StackLayout</span>>
<<span class="pl-ent">StackLayout</span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>0,20,0,0<span class="pl-pds">"</span></span> <span class="pl-e">WidthRequest</span>=<span class="pl-s"><span class="pl-pds">"</span>300<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>CenterAndExpand<span class="pl-pds">"</span></span> <span class="pl-e">Orientation</span>=<span class="pl-s"><span class="pl-pds">"</span>Vertical<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Medium<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Start<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>Select a City:<span class="pl-pds">"</span></span>/>
<<span class="pl-ent">Picker</span> <span class="pl-e">Title</span>=<span class="pl-s"><span class="pl-pds">"</span>Select a city<span class="pl-pds">"</span></span> <span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">Name</span>=<span class="pl-s"><span class="pl-pds">"</span>cityPicker<span class="pl-pds">"</span></span> <span class="pl-e">SelectedIndexChanged</span>=<span class="pl-s"><span class="pl-pds">"</span>SelectedCityChanged<span class="pl-pds">"</span></span> <span class="pl-e">WidthRequest</span>=<span class="pl-s"><span class="pl-pds">"</span>300<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>StartAndExpand<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Picker</span>.Items>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Amsterdam (NL)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Atlanta (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Buenos Aires (AR)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Cairo (EG)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Calgary (CA)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Chicago (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Dallas (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Havana (CU)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Houston (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Las Vegas (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>London (GB)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Los Angeles (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Manhattan (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>San Diego (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
<<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>Seattle (US)</<span class="pl-ent">x</span><span class="pl-ent">:</span><span class="pl-ent">String</span>>
</<span class="pl-ent">Picker</span>.Items>
</<span class="pl-ent">Picker</span>>
</<span class="pl-ent">StackLayout</span>>
</<span class="pl-ent">StackLayout</span>>
</<span class="pl-ent">ContentPage</span>></pre></div>
</li>
<li>
<p>Open <strong>LocationPage.xaml.cs</strong> and replace its contents with the following code:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">using</span> <span class="pl-en">System</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Collections.Generic</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Linq</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Text</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Threading.Tasks</span>;
<span class="pl-k">using</span> <span class="pl-en">Xamarin.Forms</span>;
<span class="pl-k">namespace</span> <span class="pl-en">CoolBreeze</span>
{
<span class="pl-k">public</span> <span class="pl-k">partial</span> <span class="pl-k">class</span> <span class="pl-en">LocationPage</span> : <span class="pl-en">ContentPage</span>
{
<span class="pl-k">public</span> <span class="pl-en">LocationPage</span>()
{
InitializeComponent();
}
<span class="pl-k">protected</span> <span class="pl-k">override</span> <span class="pl-k">void</span> <span class="pl-en">OnAppearing</span>()
{
<span class="pl-k">if</span> (cityPicker.SelectedIndex < <span class="pl-c1">0</span>) cityPicker.SelectedIndex = <span class="pl-c1">0</span>;
<span class="pl-c1">base</span>.OnAppearing();
}
<span class="pl-k">private</span> <span class="pl-k">void</span> <span class="pl-en">UseLocationToggled</span>(<span class="pl-k">object</span> <span class="pl-smi">sender</span>, <span class="pl-en">ToggledEventArgs</span> <span class="pl-smi">e</span>)
{
App.ViewModel.NeedsRefresh = <span class="pl-c1">true</span>;
<span class="pl-k">if</span> (e.Value)
{
App.ViewModel.LocationType = Common.LocationType.Location;
}
<span class="pl-k">else</span>
{
App.ViewModel.LocationType = Common.LocationType.City;
}
}
<span class="pl-k">private</span> <span class="pl-k">void</span> <span class="pl-en">SelectedCityChanged</span>(<span class="pl-k">object</span> <span class="pl-smi">sender</span>, <span class="pl-en">EventArgs</span> <span class="pl-smi">e</span>)
{
<span class="pl-k">if</span> (!App.ViewModel.IsBusy)
{
useLocationToggle.IsToggled = <span class="pl-c1">false</span>;
App.ViewModel.NeedsRefresh = <span class="pl-c1">true</span>;
App.ViewModel.LocationType = Common.LocationType.City;
<span class="pl-k">string</span> <span class="pl-en">selectedItem</span> = (sender <span class="pl-k">as</span> <span class="pl-en">Picker</span>).Items[(sender <span class="pl-k">as</span> <span class="pl-en">Picker</span>).SelectedIndex];
<span class="pl-k">var</span> <span class="pl-en">cityName </span>= selectedItem.Split(<span class="pl-s"><span class="pl-pds">'</span>(<span class="pl-pds">'</span></span>).First().Trim();
<span class="pl-k">var</span> <span class="pl-en">countryCode </span>= selectedItem.Split(<span class="pl-s"><span class="pl-pds">'</span>(<span class="pl-pds">'</span></span>).Last().Replace(<span class="pl-s"><span class="pl-pds">"</span>)<span class="pl-pds">"</span></span>, <span class="pl-s"><span class="pl-pds">"</span><span class="pl-pds">"</span></span>).Trim();
App.ViewModel.CityName = cityName;
App.ViewModel.CountryCode = countryCode;
}
App.ViewModel.IsBusy = <span class="pl-c1">false</span>;
}
}
}</pre></div>
</li>
<li>
<p>Right-click the <strong>CoolBreeze (Portable)</strong> project and use the <strong>Add</strong> > <strong>New Item...</strong> command to add another page named <strong>StartPage.xaml</strong>.</p>
<p><a href="Images/vs-adding-start-page.png" target="_blank"><img src="Images/vs-adding-start-page.png" alt="_Adding a tabbed start page" style="max-width:100%;"></a></p>
<p><em>Adding a tabbed start page</em></p>
</li>
<li>
<p>Replace the contents of <strong>StartPage.xaml</strong> file with the following XAML:</p>
<div class="highlight highlight-text-xml"><pre><?<span class="pl-ent">xml</span><span class="pl-e"> version</span>=<span class="pl-s"><span class="pl-pds">"</span>1.0<span class="pl-pds">"</span></span><span class="pl-e"> encoding</span>=<span class="pl-s"><span class="pl-pds">"</span>utf-8<span class="pl-pds">"</span></span> ?>
<<span class="pl-ent">TabbedPage</span> <span class="pl-e">xmlns</span>=<span class="pl-s"><span class="pl-pds">"</span>http://xamarin.com/schemas/2014/forms<span class="pl-pds">"</span></span>
<span class="pl-e">xmlns</span><span class="pl-e">:</span><span class="pl-e">x</span>=<span class="pl-s"><span class="pl-pds">"</span>http://schemas.microsoft.com/winfx/2009/xaml<span class="pl-pds">"</span></span>
<span class="pl-e">xmlns</span><span class="pl-e">:</span><span class="pl-e">local</span>=<span class="pl-s"><span class="pl-pds">"</span>clr-namespace:CoolBreeze<span class="pl-pds">"</span></span>
<span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">Class</span>=<span class="pl-s"><span class="pl-pds">"</span>CoolBreeze.StartPage<span class="pl-pds">"</span></span>>
<<span class="pl-ent">TabbedPage</span>.Children>
<<span class="pl-ent">local</span><span class="pl-ent">:</span><span class="pl-ent">LocationPage</span> <span class="pl-e">Icon</span>=<span class="pl-s"><span class="pl-pds">"</span>location.png<span class="pl-pds">"</span></span> <span class="pl-e">Title</span>=<span class="pl-s"><span class="pl-pds">"</span>LOCATION<span class="pl-pds">"</span></span>/>
<<span class="pl-ent">local</span><span class="pl-ent">:</span><span class="pl-ent">MainPage</span> <span class="pl-e">Icon</span>=<span class="pl-s"><span class="pl-pds">"</span>today.png<span class="pl-pds">"</span></span> <span class="pl-e">Title</span>=<span class="pl-s"><span class="pl-pds">"</span>NOW<span class="pl-pds">"</span></span>/>
</<span class="pl-ent">TabbedPage</span>.Children>
</<span class="pl-ent">TabbedPage</span>></pre></div>
</li>
<li>
<p>Open <strong>StartPage.xaml.cs</strong> and replace its contents with the following code:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">using</span> <span class="pl-en">System</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Collections.Generic</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Linq</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Text</span>;
<span class="pl-k">using</span> <span class="pl-en">System.Threading.Tasks</span>;
<span class="pl-k">using</span> <span class="pl-en">Xamarin.Forms</span>;
<span class="pl-k">namespace</span> <span class="pl-en">CoolBreeze</span>
{
<span class="pl-k">public</span> <span class="pl-k">partial</span> <span class="pl-k">class</span> <span class="pl-en">StartPage</span> : <span class="pl-en">TabbedPage</span>
{
<span class="pl-k">public</span> <span class="pl-en">StartPage</span>()
{
InitializeComponent();
}
<span class="pl-k">protected</span> <span class="pl-k">override</span> <span class="pl-k">void</span> <span class="pl-en">OnAppearing</span>()
{
InitializeAppAsync();
<span class="pl-c1">base</span>.OnAppearing();
}
<span class="pl-k">private</span> <span class="pl-k">void</span> <span class="pl-en">InitializeAppAsync</span>()
{
<span class="pl-k">if</span> (App.ViewModel == <span class="pl-c1">null</span>) App.ViewModel = <span class="pl-k">new</span> <span class="pl-en">MainViewModel</span>();
}
}
}</pre></div>
</li>
<li>
<p>Open <strong>MainPage.xaml</strong> in the <strong>CoolBreeze (Portable)</strong> project and locate the <code>Picker</code> control:</p>
<p><a href="Images/vs-main-picker.png" target="_blank"><img src="Images/vs-main-picker.png" alt="The city-picker control" style="max-width:100%;"></a></p>
<p><em>The city-picker control</em></p>
</li>
<li>
<p>Remove the <code>Picker</code> control and replace it with the following <code>Label</code> control:</p>
<div class="highlight highlight-text-xml"><pre><<span class="pl-ent">Label</span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>0,60,0,0<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Start<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span>
Text=<span class="pl-s"><span class="pl-pds">"</span>{Binding CurrentConditions.DisplayName}<span class="pl-pds">"</span></span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Medium<span class="pl-pds">"</span></span>/></pre></div>
</li>
<li>
<p>Open <strong>MainPage.xaml.cs</strong>. Find the method named <code>OnAppearing</code> and replace it with the following <code>OnAppearing</code> method:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">protected</span> <span class="pl-k">override</span> <span class="pl-k">void</span> <span class="pl-en">OnAppearing</span>()
{
<span class="pl-c1">this</span>.BindingContext = App.ViewModel;
<span class="pl-k">if</span> (App.ViewModel.NeedsRefresh) App.ViewModel.RefreshCurrentConditionsAsync();
<span class="pl-c1">base</span>.OnAppearing();
}</pre></div>
</li>
<li>
<p>Still in <strong>MainPage.xaml.cs</strong>, find the <code>SelectedCityChanged</code> method and delete it from the file.</p>
</li>
<li>
<p>Open <strong>App.xaml.cs</strong> in the <strong>CoolBreeze (Portable)</strong> project. In the class constructor, modify the line of code that instantiates the <code>MainPage</code> class so that it instantiates <code>StartPage</code> instead.</p>
<p><a href="Images/vs-updated-app-constructor.png" target="_blank"><img src="Images/vs-updated-app-constructor.png" alt="The updated App constructor" style="max-width:100%;"></a></p>
<p><em>The updated App constructor</em></p>
</li>
<li>
<p>Open <strong>WeatherHelper.cs</strong> in the "Helpers" folder of the <strong>CoolBreeze (Portable)</strong> project. Add the following method to the <code>WeatherHelper</code> class. DO NOT delete the <code>GetCurrentConditionsAsync</code> method that is already there; rather, add the new one and leave the old one in place. The new method accepts a longitude and latitude as parameters.</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">static</span> <span class="pl-en">Task</span><<span class="pl-en">WeatherInformation</span>> <span class="pl-en">GetCurrentConditionsAsync</span>(<span class="pl-k">double</span> <span class="pl-smi">latitude</span>, <span class="pl-k">double</span> <span class="pl-smi">longitude</span>)
{
<span class="pl-k">string</span> <span class="pl-en">url</span> = <span class="pl-pds">$"</span><span class="pl-s">http://traininglabservices.azurewebsites.net/api/weather/current?latitude=</span>{latitude}<span class="pl-s">&longitude=</span>{longitude}<span class="pl-s">&registrationCode=</span>{App.RegistrationCode}<span class="pl-pds">"</span>;
<span class="pl-en">HttpClient</span> <span class="pl-en">client</span> = <span class="pl-k">new</span> <span class="pl-en">HttpClient</span>();
<span class="pl-k">var</span> <span class="pl-en">response </span>= <span class="pl-k">await</span> client.GetStringAsync(url);
<span class="pl-k">var</span> <span class="pl-en">result </span>= Newtonsoft.Json.JsonConvert.DeserializeObject<WeatherInformation>(<span class="pl-en">response</span>);
<span class="pl-k">return</span> result;
}</pre></div>
</li>
<li>
<p>Open <strong>MainViewModel.cs</strong> in the "ViewModels" folder of the <strong>CoolBreeze (Portable)</strong> project. Add the following statements to the <code>MainViewModel</code> class to add a <code>Location</code> property to the view-model:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">private</span> <span class="pl-en">Plugin.Geolocator.Abstractions.Position</span> _location;
<span class="pl-k">public</span> <span class="pl-en">Plugin.Geolocator.Abstractions.Position</span> Location
{
<span class="pl-k">get</span> { <span class="pl-k">return</span> <span class="pl-c1">this</span>._location; }
<span class="pl-k">set</span> { <span class="pl-c1">this</span>.SetProperty(ref <span class="pl-c1">this</span>._location, <span class="pl-k">value</span>); }
}</pre></div>
</li>
<li>
<p>Still in <strong>MainViewModel.cs</strong>, replace the <code>RefreshCurrentConditionsAsync</code> method with this one:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">void</span> <span class="pl-en">RefreshCurrentConditionsAsync</span>()
{
<span class="pl-c1">this</span>.IsBusy = <span class="pl-c1">true</span>;
<span class="pl-c1">this</span>.NeedsRefresh = <span class="pl-c1">false</span>;
<span class="pl-en">WeatherInformation</span> <span class="pl-en">results</span> = <span class="pl-c1">null</span>;
<span class="pl-k">switch</span> (<span class="pl-c1">this</span>.LocationType)
{
<span class="pl-k">case</span> LocationType.Location:
<span class="pl-k">if</span> (<span class="pl-c1">this</span>.Location == <span class="pl-c1">null</span>) <span class="pl-c1">this</span>.Location = <span class="pl-k">await</span> Helpers.LocationHelper.GetCurrentLocationAsync();
results = <span class="pl-k">await</span> Helpers.WeatherHelper.GetCurrentConditionsAsync(<span class="pl-c1">this</span>.Location.Latitude, <span class="pl-c1">this</span>.Location.Longitude);
<span class="pl-k">break</span>;
<span class="pl-k">case</span> LocationType.City:
results = <span class="pl-k">await</span> Helpers.WeatherHelper.GetCurrentConditionsAsync(<span class="pl-c1">this</span>.CityName, <span class="pl-c1">this</span>.CountryCode);
<span class="pl-k">break</span>;
}
<span class="pl-c1">this</span>.CurrentConditions.Conditions = results.Conditions;
<span class="pl-c1">this</span>.CurrentConditions.Description = results.Description;
<span class="pl-c1">this</span>.CurrentConditions.DisplayName = results.DisplayName;
<span class="pl-c1">this</span>.CurrentConditions.Icon = results.Icon;
<span class="pl-c1">this</span>.CurrentConditions.Id = results.Id;
<span class="pl-c1">this</span>.CurrentConditions.MaxTemperature = results.MaxTemperature;
<span class="pl-c1">this</span>.CurrentConditions.MinTemperature = results.MinTemperature;
<span class="pl-c1">this</span>.CurrentConditions.Temperature = results.Temperature;
<span class="pl-c1">this</span>.CurrentConditions.Humidity = results.Humidity;
<span class="pl-c1">this</span>.CurrentConditions.TimeStamp = results.TimeStamp.ToLocalTime();
<span class="pl-c1">this</span>.IsBusy = <span class="pl-c1">false</span>;
}</pre></div>
</li>
<li>
<p>Now let's add some flair to the user interface by adding icons to the tabs in the tabbed page. Recall that image assets typically need to be placed in specific locations for each platform. In Solution Explorer, right-click the "drawable" folder in the <strong>CoolBreeze.Android</strong> project and select <strong>Add</strong> > <strong>Existing Item...</strong> from the context menu.</p>
<p><a href="Images/vs-add-to-drawable.png" target="_blank"><img src="Images/vs-add-to-drawable.png" alt="Adding items to the drawable folder" style="max-width:100%;"></a></p>
<p><em>Adding items to the drawable folder</em></p>
</li>
<li>
<p>Browse to the "Resources\Droid\Resources\drawable" folder in the zip file containing this challenge and select all of the files in that folder. Then click <strong>Add</strong>.</p>
<p><a href="Images/fe-drawable.png" target="_blank"><img src="Images/fe-drawable.png" alt="Adding items to the "drawable" folder" style="max-width:100%;"></a></p>
<p><em>Adding items to the "drawable" folder</em></p>
</li>
<li>
<p>Repeat Steps 15 and 16 to add all the files in the zip file's "Resources\iOS\Resources" folder to the "Resources" folder of the <strong>CoolBreeze.iOS</strong> project.</p>
</li>
<li>
<p>Repeat Steps 15 and 16 to add all the files in the zip file's "Resources\UWP" folder to the root of the <strong>CoolBreeze.UWP</strong> project.</p>
</li>
<li>
<p>The next step is to build the app and test it. You can test location services in most mobile emulators, but it's easy enough to test on your PC. Right-click the <strong>CoolBreeze.UWP (Universal Windows)</strong> project and select <strong>Set as StartUp Project</strong> to make it the startup project. Right-click the project again and select <strong>Deploy</strong>. Now launch CoolBreeze on your local machine by clicking the <strong>Run</strong> button in the toolbar.</p>
<p><a href="Images/run-uwp.png" target="_blank"><img src="Images/run-uwp.png" alt="Running CoolBreeze on the local machine" style="max-width:100%;"></a></p>
<p><em>Running CoolBreeze on the local machine</em></p>
</li>
<li>
<p>Observe the new tabbed navigation elements at the top of the page:</p>
<p><a href="Images/app-uwp-tabs.png" target="_blank"><img src="Images/app-uwp-tabs.png" alt="CoolBreeze's new tabbed UI" style="max-width:100%;"></a></p>
<p><em>CoolBreeze's new tabbed UI</em></p>
</li>
<li>
<p>Toggle <strong>Use my current location</strong> to <strong>On</strong>, and then click the <strong>NOW</strong> tab to view weather conditions at your current location.</p>
<p><a href="Images/app-use-location.png" target="_blank"><img src="Images/app-use-location.png" alt="Enabling "Use my current location"" style="max-width:100%;"></a></p>
<p><em>Enabling "Use my current location"</em></p>
</li>
<li>
<p>When prompted for permission to access your current location, click <strong>Yes</strong>.</p>
<p><a href="Images/app-allow-location.png" target="_blank"><img src="Images/app-allow-location.png" alt="Allowing CoolBreeze to use your location" style="max-width:100%;"></a></p>
<p><em>Allowing CoolBreeze to use your location</em></p>
</li>
<li>
<p>Confirm that CoolBreeze reports the weather at your current location.</p>
<p><a href="Images/app-local-condtions.png" target="_blank"><img src="Images/app-local-condtions.png" alt="CoolBreeze showing the weather in Pecan Grove, TX" style="max-width:100%;"></a></p>
<p><em>CoolBreeze showing the weather in Pecan Grove, TX</em></p>
</li>
</ol>
<p>Feel free to run the app on iOS and Android as well to see how it behaves there. Most emulators allow you to set the current location in order to test apps that use geolocation services by varying the location that the geolocation API returns.</p>
<p><a name="Exercise3"></a></p>
<h2>Exercise 3: Add toolbar navigation to the app</h2>
<p>In this exercise, you will further enhance CoolBreeze by adding a master/detail view allowing users to view weather forecasts as well as current weather conditions. You will also add a toolbar to facilitate switching from the view showing the current weather to the view showing the weather forecast.</p>
<ol>
<li>
<p>Open <strong>WeatherHelper.cs</strong> in the "Helpers" folder of the <strong>CoolBreeze (Portable)</strong> project. Then add the following methods to the <code>WeatherHelper</code> class:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">static</span> <span class="pl-en">Task</span><<span class="pl-en">List</span><<span class="pl-en">WeatherInformation</span>>> <span class="pl-en">GetForecastAsync</span>(<span class="pl-k">double</span> <span class="pl-smi">latitude</span>, <span class="pl-k">double</span> <span class="pl-smi">longitude</span>)
{
<span class="pl-k">string</span> <span class="pl-en">url</span> = <span class="pl-pds">$"</span><span class="pl-s">http://traininglabservices.azurewebsites.net/api/weather/forecast?latitude=</span>{latitude}<span class="pl-s">&longitude=</span>{longitude}<span class="pl-s">&registrationCode=</span>{App.RegistrationCode}<span class="pl-pds">"</span>;
<span class="pl-en">HttpClient</span> <span class="pl-en">client</span> = <span class="pl-k">new</span> <span class="pl-en">HttpClient</span>();
<span class="pl-k">var</span> <span class="pl-en">response </span>= <span class="pl-k">await</span> client.GetStringAsync(url);
<span class="pl-k">var</span> <span class="pl-en">result </span>= Newtonsoft.Json.JsonConvert.DeserializeObject<List<WeatherInformation>>(<span class="pl-en">response</span>);
<span class="pl-k">return</span> result;
}
<span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">static</span> <span class="pl-en">Task</span><<span class="pl-en">List</span><<span class="pl-en">WeatherInformation</span>>> <span class="pl-en">GetForecastAsync</span>(<span class="pl-k">string</span> <span class="pl-smi">cityName</span>, <span class="pl-k">string</span> <span class="pl-smi">countryCode</span>)
{
<span class="pl-k">string</span> <span class="pl-en">url</span> = <span class="pl-pds">$"</span><span class="pl-s">http://traininglabservices.azurewebsites.net/api/weather/forecast/city?cityName=</span>{cityName}<span class="pl-s">&countryCode=</span>{countryCode}<span class="pl-s">&registrationCode=</span>{App.RegistrationCode}<span class="pl-pds">"</span>;
<span class="pl-en">HttpClient</span> <span class="pl-en">client</span> = <span class="pl-k">new</span> <span class="pl-en">HttpClient</span>();
<span class="pl-k">var</span> <span class="pl-en">response </span>= <span class="pl-k">await</span> client.GetStringAsync(url);
<span class="pl-k">var</span> <span class="pl-en">result </span>= Newtonsoft.Json.JsonConvert.DeserializeObject<List<WeatherInformation>>(<span class="pl-en">response</span>);
<span class="pl-k">return</span> result;
}</pre></div>
</li>
<li>
<p>Open <strong>MainViewModel.cs</strong> in the "ViewModels" folder of the <strong>CoolBreeze (Portable)</strong> project. Add the following statements to the <code>MainViewModel</code> class to add a <code>Forecast</code> property to the view-model.</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">private</span> <span class="pl-en">ObservableCollection</span><<span class="pl-en">WeatherInformation</span>> <span class="pl-en">_forecast</span>;
<span class="pl-k">public</span> <span class="pl-en">ObservableCollection</span><<span class="pl-en">WeatherInformation</span>> Forecast
{
<span class="pl-k">get</span> { <span class="pl-k">if</span> (<span class="pl-c1">this</span>._forecast == <span class="pl-c1">null</span>) <span class="pl-c1">this</span>._forecast = <span class="pl-k">new</span> <span class="pl-en">ObservableCollection</span><WeatherInformation>(); <span class="pl-k">return</span> <span class="pl-c1">this</span>._forecast; }
<span class="pl-k">set</span> { <span class="pl-c1">this</span>.SetProperty(ref <span class="pl-c1">this</span>._forecast, <span class="pl-k">value</span>); }
}</pre></div>
</li>
<li>
<p>Paste the following method into the <code>MainViewModel</code> class:</p>
<div class="highlight highlight-source-cs"><pre><span class="pl-k">public</span> <span class="pl-k">async</span> <span class="pl-k">void</span> <span class="pl-en">RefreshForecastAsync</span>()
{
<span class="pl-c1">this</span>.IsBusy = <span class="pl-c1">true</span>;
<span class="pl-c1">this</span>.NeedsRefresh = <span class="pl-c1">false</span>;
<span class="pl-en">List</span><<span class="pl-en">WeatherInformation</span>> <span class="pl-en">results</span> = <span class="pl-c1">null</span>;
<span class="pl-c1">this</span>.Forecast.Clear();
<span class="pl-k">switch</span> (<span class="pl-c1">this</span>.LocationType)
{
<span class="pl-k">case</span> LocationType.Location:
<span class="pl-k">if</span> (<span class="pl-c1">this</span>.Location == <span class="pl-c1">null</span>) <span class="pl-c1">this</span>.Location = <span class="pl-k">await</span> Helpers.LocationHelper.GetCurrentLocationAsync();
results = <span class="pl-k">await</span> Helpers.WeatherHelper.GetForecastAsync(<span class="pl-c1">this</span>.Location.Latitude, <span class="pl-c1">this</span>.Location.Longitude);
<span class="pl-k">break</span>;
<span class="pl-k">case</span> LocationType.City:
results = <span class="pl-k">await</span> Helpers.WeatherHelper.GetForecastAsync(<span class="pl-c1">this</span>.CityName, <span class="pl-c1">this</span>.CountryCode);
<span class="pl-k">break</span>;
}
<span class="pl-k">foreach</span> (var result <span class="pl-k">in</span> results)
{
<span class="pl-c1">this</span>.Forecast.Add(result);
}
<span class="pl-c1">this</span>.IsBusy = <span class="pl-c1">false</span>;
}</pre></div>
</li>
<li>
<p>Right-click the <strong>CoolBreeze (Portable)</strong> project and use the <strong>Add</strong> > <strong>New Item...</strong> command to add a page named <strong>ForecastPage.xaml</strong> to the project.</p>
<p><a href="Images/vs-adding-forecast-page.png" target="_blank"><img src="Images/vs-adding-forecast-page.png" alt="Adding a forecast page" style="max-width:100%;"></a></p>
<p><em>Adding a forecast page</em></p>
</li>
<li>
<p>Replace the contents of <strong>ForecastPage.xaml</strong> with the following XAML:</p>
<div class="highlight highlight-text-xml"><pre><?<span class="pl-ent">xml</span><span class="pl-e"> version</span>=<span class="pl-s"><span class="pl-pds">"</span>1.0<span class="pl-pds">"</span></span><span class="pl-e"> encoding</span>=<span class="pl-s"><span class="pl-pds">"</span>utf-8<span class="pl-pds">"</span></span> ?>
<<span class="pl-ent">ContentPage</span> <span class="pl-e">xmlns</span>=<span class="pl-s"><span class="pl-pds">"</span>http://xamarin.com/schemas/2014/forms<span class="pl-pds">"</span></span>
<span class="pl-e">xmlns</span><span class="pl-e">:</span><span class="pl-e">x</span>=<span class="pl-s"><span class="pl-pds">"</span>http://schemas.microsoft.com/winfx/2009/xaml<span class="pl-pds">"</span></span> <span class="pl-e">Title</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding CurrentConditions.DisplayName}<span class="pl-pds">"</span></span>
<span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">Class</span>=<span class="pl-s"><span class="pl-pds">"</span>CoolBreeze.ForecastPage<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Grid</span>>
<<span class="pl-ent">ListView</span> <span class="pl-e">Margin</span>=<span class="pl-s"><span class="pl-pds">"</span>40<span class="pl-pds">"</span></span> <span class="pl-e">ItemsSource</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding Forecast}<span class="pl-pds">"</span></span> >
<<span class="pl-ent">ListView</span>.ItemTemplate>
<<span class="pl-ent">DataTemplate</span>>
<<span class="pl-ent">ViewCell</span>>
<<span class="pl-ent">StackLayout</span> <span class="pl-e">Orientation</span>=<span class="pl-s"><span class="pl-pds">"</span>Horizontal<span class="pl-pds">"</span></span>>
<<span class="pl-ent">Image</span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Aspect</span>=<span class="pl-s"><span class="pl-pds">"</span>AspectFit<span class="pl-pds">"</span></span> <span class="pl-e">HeightRequest</span>=<span class="pl-s"><span class="pl-pds">"</span>40<span class="pl-pds">"</span></span> <span class="pl-e">WidthRequest</span>=<span class="pl-s"><span class="pl-pds">"</span>40<span class="pl-pds">"</span></span> <span class="pl-e">Source</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding Icon, Converter={StaticResource IconToUrlConverter}}<span class="pl-pds">"</span></span> />
<<span class="pl-ent">Label</span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Micro<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding TimeStamp, Converter={StaticResource ForecastTimeLabelConverter}}<span class="pl-pds">"</span></span> />
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Medium<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding Conditions}<span class="pl-pds">"</span></span> />
<<span class="pl-ent">Label</span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding MaxTemperaturem, Converter={StaticResource CharacterLabelConverter}, ConverterParameter=°}<span class="pl-pds">"</span></span> />
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Small<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>HUMIDITY: <span class="pl-pds">"</span></span>/>
<<span class="pl-ent">Label</span> <span class="pl-e">FontSize</span>=<span class="pl-s"><span class="pl-pds">"</span>Small<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">Text</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding Humidity, Converter={StaticResource CharacterLabelConverter}, ConverterParameter=%}<span class="pl-pds">"</span></span> />
</<span class="pl-ent">StackLayout</span>>
</<span class="pl-ent">ViewCell</span>>
</<span class="pl-ent">DataTemplate</span>>
</<span class="pl-ent">ListView</span>.ItemTemplate>
</<span class="pl-ent">ListView</span>>
<<span class="pl-ent">ActivityIndicator</span> <span class="pl-e">Color</span>=<span class="pl-s"><span class="pl-pds">"</span>{StaticResource AppAccentColor}<span class="pl-pds">"</span></span> <span class="pl-e">VerticalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">HorizontalOptions</span>=<span class="pl-s"><span class="pl-pds">"</span>Center<span class="pl-pds">"</span></span> <span class="pl-e">IsRunning</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding IsBusy}<span class="pl-pds">"</span></span> <span class="pl-e">IsEnabled</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding IsBusy}<span class="pl-pds">"</span></span> <span class="pl-e">IsVisible</span>=<span class="pl-s"><span class="pl-pds">"</span>{Binding IsBusy}<span class="pl-pds">"</span></span>>
<<span class="pl-ent">ActivityIndicator</span>.WidthRequest>
<<span class="pl-ent">OnPlatform</span> <span class="pl-e">x</span><span class="pl-e">:</span><span class="pl-e">TypeArguments</span>=<span class="pl-s"><span class="pl-pds">"</span>x:Double<span class="pl-pds">"</span></span> <span class="pl-e">iOS</span>=<span class="pl-s"><span class="pl-pds">"</span>100<span class="pl-pds">"</span></span> <span class="pl-e">Android</span>=<span class="pl-s"><span class="pl-pds">"</span>100<span class="pl-pds">"</span></span> <span class="pl-e">WinPhone</span>=<span class="pl-s"><span class="pl-pds">"</span>400<span class="pl-pds">"</span></span> />
</<span class="pl-ent">ActivityIndicator</span>.WidthRequest>
</<span class="pl-ent">ActivityIndicator</span>>
</<span class="pl-ent">Grid</span>>
</<span class="pl-ent">ContentPage</span>></pre></div>
</li>
<li>