Merge pull request #167 from syncfusion/PullToRefresh

954484-Fix the PullToRefresh issues in the Maui Toolkit that occurs during testing.

Author: PaulAndersonS

maui/samples/Gallery/Samples/PullToRefresh/ListViewPullToRefresh/View/ListViewPullToRefresh.xaml.cs

@@ -4,7 +4,13 @@ public partial class ListViewPullToRefresh : SampleView
 	{
 		public ListViewPullToRefresh()
 		{
-			InitializeComponent();
+			InitializeComponent();			
+		}
+
+		public override void OnDisappearing()
+		{
+			base.OnDisappearing();
+			pullToRefresh.Handler?.DisconnectHandler();
 		}
 	}
 }

maui/samples/Gallery/Samples/PullToRefresh/PullToRefreshView/View/PullToRefreshView.xaml.cs

@@ -4,7 +4,13 @@ public partial class PullToRefreshView : SampleView
 	{
 		public PullToRefreshView()
 		{
-			InitializeComponent();
+			InitializeComponent();			
+		}
+
+		public override void OnDisappearing()
+		{
+			base.OnDisappearing();
+			pullToRefresh.Handler?.DisconnectHandler();
 		}
 	}
 }