[iOS/Critical] Fix ListView memory leaks (#524)

* fix memory leaks

added sample code

changed page name

Changed page title

add screen instructions

fix copy paste error

change subview dispose logic

Fix context action memory leak

add sample code

change custom page names

Revert "change custom page names"

This reverts commit 7aaab2625d9526080ca5c51c02e909f09ee3f610.

changed class names

changes

UI test for 32206

update ui test

fix whitespace

UITests done

* run UI tests on iOS only

* fix code style

* dispose prototype

* fix child renderer issue

* add null check

1 files changed, 17 insertions, 1 deletions

diff --git a/Xamarin.Forms.Platform.iOS/Cells/CellTableViewCell.cs b/Xamarin.Forms.Platform.iOS/Cells/CellTableViewCell.cs
index e32e86cd..b42f69f4 100644
--- a/Xamarin.Forms.Platform.iOS/Cells/CellTableViewCell.cs
+++ b/Xamarin.Forms.Platform.iOS/Cells/CellTableViewCell.cs
@@ -7,8 +7,8 @@ namespace Xamarin.Forms.Platform.iOS
 	public class CellTableViewCell : UITableViewCell, INativeElementView
 	{
 		Cell _cell;
-
 		public Action<object, PropertyChangedEventArgs> PropertyChanged;
+		bool _disposed;
 
 		public CellTableViewCell(UITableViewCellStyle style, string key) : base(style, key)
 		{
@@ -95,5 +95,21 @@ namespace Xamarin.Forms.Platform.iOS
 
 			return nativeCell;
 		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (_disposed)
+				return;
+
+			if (disposing)
+			{
+				PropertyChanged = null;
+				_cell = null;
+			}
+
+			_disposed = true;
+
+			base.Dispose(disposing);
+		}
 	}
 }
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