System.ArgumentOutOfRangeException in LayoutAnchorableTabItem.OnMouseEnter line 189

[sharpSteff]

Received following issue:

Top-level Exception Type: System.ArgumentOutOfRangeException Message: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index Source: mscorlib Stack Trace: at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource) at System.Collections.Generic.List1.get_Item(Int32 index)
at System.Collections.ObjectModel.Collection1.get_Item(Int32 index) at System.Collections.ObjectModel.ObservableCollection1.MoveItem(Int32 oldIndex, Int32 newIndex)
at Xceed.Wpf.AvalonDock.Layout.LayoutGroup1.MoveChild(Int32 oldIndex, Int32 newIndex) in F:\MyFiles\CSharp\00_GitHub\Avalondock\source\Components\Xceed.Wpf.AvalonDock\Layout\LayoutGroup.cs:line 116 at Xceed.Wpf.AvalonDock.Controls.LayoutAnchorableTabItem.OnMouseEnter(MouseEventArgs e) in F:\MyFiles\CSharp\00_GitHub\Avalondock\source\Components\Xceed.Wpf.AvalonDock\Controls\LayoutAnchorableTabItem.cs:line 189 at System.Windows.UIElement.OnMouseEnterThunk(Object sender, MouseEventArgs e)

Its a sporadic issue, which occurs when there is some load in our application.

We applied a hotfix with prechecking the indexes before executing containerPane.MoveChild

if (newindex < containerPane.ChildrenCount && oldIndex > -1) { containerPane.MoveChild(oldIndex, newindex); }

[Dirkster99]

Just to be sure, you are referring to this line:

var childrenList = container.Children.ToList();
containerPane.MoveChild( childrenList.IndexOf( _draggingItem.Model ), childrenList.IndexOf( model ) );

and the suggested fix is this, right(?):

var childrenList = container.Children.ToList();
var oldIndex = childrenList.IndexOf( _draggingItem.Model );
var newIndex = childrenList.IndexOf( model );

if (newindex < containerPane.ChildrenCount && oldIndex > -1)
  containerPane.MoveChild( oldIndex, newIndex );

[sharpSteff]

Yes your right.
However this was only a hotfix.

I think there is a threading issue Back in the containerPane.

[Dirkster99]

yes, I understand that, but I thought its better to have at least a hot fix to avoid the crash rather than having it crashing ... one problem is that I cannot verify the problem as I don't have it (not even sporadic) so unless we get a bette chance to debug and fix it - I can't really do more than hot fixing this....?

[sharpSteff]

OK great, a hotfix would do it for now.
Thanks for your effort

[Dirkster99]

This commit should hot fix this issue (soon to be released to Nuget)