[Bug] ListView HasUnevenRows was not working in iOS 10 (#6166)

* Add repro for #5888

Co-Authored-By: melimion <[email protected]>

* [iOS] Fix HasUnevenRows for iOS11+

Co-Authored-By: melimion <[email protected]>
fixes #5888

Author: samhouts

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue5888.cs

@@ -0,0 +1,26 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+
+namespace Xamarin.Forms.Controls.Issues
+{
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Github, 5888, "[Bug] ListView HasUnevenRows is not working in iOS 10", PlatformAffected.iOS)]
+	public class Issue5888 : TestContentPage 
+	{
+		protected override void Init()
+		{
+
+			var stack2 = new StackLayout
+			{
+				Children = { new Label { Text = "Hi" }, new Label { Text = "Bye" }, new Label { Text = "Open" } }
+			};
+			var listview = new ListView
+			{
+				HasUnevenRows = true,
+				ItemTemplate = new DataTemplate(() => new ViewCell { View = stack2 }),
+				ItemsSource = new string[] { "mono", "monodroid" }
+			};
+			Content = new StackLayout { Children = { listview } };
+		}
+	}
+}

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

@@ -892,6 +892,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Issue4356.cs">
       <DependentUpon>Issue4356.xaml</DependentUpon>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Issue5888.cs" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="$(MSBuildThisFileDirectory)Bugzilla22229.xaml">

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

@@ -711,7 +711,7 @@ void UpdateSpinnerColor()
 
 			if (_tableViewController != null)
 				_tableViewController.UpdateRefreshControlColor(color == Color.Default ? null : color.ToUIColor());
-    }
+		}
 
 		void UpdateVerticalScrollBarVisibility()
 		{
@@ -817,11 +817,11 @@ internal override void InvalidatingPrototypicalCellCache()
 
 			protected override void UpdateEstimatedRowHeight(UITableView tableView)
 			{
-				var estimatedRowheight  = GetEstimatedRowHeight(tableView);
+				var estimatedRowHeight = GetEstimatedRowHeight(tableView);
 				//if we are providing 0 we are disabling EstimatedRowHeight,
 				//this works fine on newer versions, but iOS10 it will cause a crash so we leave the default value
-				if (estimatedRowheight == 0 && Forms.IsiOS11OrNewer)
-					tableView.EstimatedRowHeight = estimatedRowheight;
+				if (estimatedRowHeight > 0 || (estimatedRowHeight == 0 && Forms.IsiOS11OrNewer))
+					tableView.EstimatedRowHeight = estimatedRowHeight;
 			}
 
 			internal Cell GetPrototypicalCell(NSIndexPath indexPath)
@@ -1247,7 +1247,7 @@ public void UpdateGrouping()
 			{
 				UpdateShortNameListener();
 
-				if(List.OnThisPlatform().RowAnimationsEnabled())
+				if (List.OnThisPlatform().RowAnimationsEnabled())
 					_uiTableView.ReloadData();
 				else
 					PerformWithoutAnimation(() => { _uiTableView.ReloadData(); });
@@ -1551,7 +1551,8 @@ public void UpdateShowHideRefresh(bool shouldHide)
 		public override void ViewWillAppear(bool animated)
 		{
 			(TableView?.Source as ListViewRenderer.ListViewDataSource)?.Cleanup();
-			if (!_list.IsRefreshing || !_refresh.Refreshing) return;
+			if (!_list.IsRefreshing || !_refresh.Refreshing)
+				return;
 
 			// Restart the refreshing to get the animation to trigger
 			UpdateIsRefreshing(false);