[iOS] Picker - Fix VoiceOver reading reading row twice (#14209)

* only reload picker on collection change

* Add sample to projitems

Co-authored-by: Mike Herman <c-michael.herman@charter.com>
Co-authored-by: rachelkang <rachelkang@microsoft.com>
Co-authored-by: Gerald Versluis <gerald.versluis@microsoft.com>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue13193.cs

@@ -0,0 +1,58 @@
+using System.Collections.Generic;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.ManualReview)]
+	[Category(UITestCategories.Accessibility)]
+#endif
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 13193,
+		"Double prompt when voice over reads picker item on iOS",
+		PlatformAffected.iOS)]
+	public class Issue13193 : TestContentPage
+	{
+		public Issue13193()
+		{
+		}
+
+		protected override void Init()
+		{
+			Title = "Issue 13193";
+
+			var layout = new StackLayout
+			{
+				Padding = 12
+			};
+
+			var instructions = new Label
+			{
+				Text = "Turn VoiceOver on, select the picker, double-tap to edit, select the input view, and swipe up to navigate through the picker items.  If an item or a truncated portion of an item is read twice, the test failed"
+			};
+
+			var picker = new Picker
+			{
+				ItemsSource = new List<string>
+				{
+					"Bananas",
+					"New York",
+					"Grapes"
+				}
+			};
+
+			layout.Children.Add(instructions);
+			layout.Children.Add(picker);
+
+			Content = layout;
+
+		}
+	}
+}

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Xamarin.Forms.Controls.Issues.Shared.projitems

@@ -1814,6 +1814,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue13616.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue13670.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue13684.xaml.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Issue13193.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue14066.xaml.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue8129.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Issue12300.cs" />

Xamarin.Forms.Platform.iOS/Renderers/PickerRenderer.cs

@@ -179,6 +179,7 @@ void OnStarted(object sender, EventArgs eventArgs)
 
 		void RowsCollectionChanged(object sender, EventArgs e)
 		{
+			_picker.ReloadAllComponents();
 			UpdatePicker();
 		}
 
@@ -241,7 +242,6 @@ void UpdatePicker()
 			var oldText = Control.Text;
 			Control.Text = selectedIndex == -1 || items == null || selectedIndex >= items.Count ? "" : items[selectedIndex];
 			UpdatePickerNativeSize(oldText);
-			_picker.ReloadAllComponents();
 			if (items == null || items.Count == 0)
 				return;