fix nre when changing content in datepickerselected (#494)

1 files changed, 58 insertions, 0 deletions

diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla38723.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla38723.cs
new file mode 100644
index 00000000..2defadec
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla38723.cs
@@ -0,0 +1,58 @@
+using System;
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+#if UITEST
+using Xamarin.UITest;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 38723, "Update Content in Picker's SelectedIndexChanged event causes NullReferenceException", PlatformAffected.iOS)]
+	public class Bugzilla38723 : TestContentPage // or TestMasterDetailPage, etc ...
+	{
+		Picker _datePicker;
+		Label _dateLabel;
+
+		protected override void Init()
+		{
+			_datePicker = new Picker
+			{
+				//HorizontalOptions = LayoutOptions.FillAndExpand,
+				VerticalOptions = LayoutOptions.Center,
+				Title = "Pick a Date",
+			};
+			_datePicker.SelectedIndexChanged += DatePickerSelected;
+
+			for (var i = 0; i < 7; i++)
+			{
+				_datePicker.Items.Add(DateTime.Now.AddDays(i).ToString("dd, MMM, yyyy(dddd)"));
+			}
+
+			var stackLayout = new StackLayout
+			{
+				Padding = new Thickness(10, 10)
+			};
+
+			_dateLabel = new Label
+			{
+				HorizontalOptions = LayoutOptions.StartAndExpand,
+				VerticalOptions = LayoutOptions.Center,
+				Text = "Placeholder"
+			};
+
+			stackLayout.Children.Add(_datePicker);
+			stackLayout.Children.Add(_dateLabel);
+			// Update current page's UI would cause NullReferenceException
+			Content = stackLayout;
+		}
+
+		void DatePickerSelected(object sender, EventArgs args)
+		{
+			_dateLabel.Text = args.ToString();
+			Content = _dateLabel;
+		}
+	}
+}
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