Forums Retired Products and Controls
Your Privacy Matters: We use our own and third-party cookies to improve your experience on our website. By continuing to use the website we understand that you accept their use. Cookie Policy
Close
myles
306
Memory leak
posted

We are using the drag drop manager in some of our xaml view pages and believe there are memory leaks caused by the Infragistics drag drop framework.  We are using WinDbg to track the leak down.  Here is the output from WinDbg when inspecting the heap after the suspect page has closed:

------------------------------------------------------------------------------------------------------------------------------------------

0:031> !dumpheap -type Infragistics.Silverlight.Controls.XamWebTileView

Address MT Size

07f1083c 0a27f510 136

07fe6aac 0a27f510 136

08092e70 0a27f510 136

081395f8 0a27f510 136

081fb45c 0a27f510 136

082cb060 0a27f510 136

total 6 objects

Statistics:

MT Count TotalSize Class Name

0a27f510 6 816 Infragistics.Silverlight.Controls.XamWebTileView

Total 6 objects

0:031> !gcroot 082cb060

Note: Roots found on stacks may be false positives. Run "!help gcroot" for

more info.

Scan Thread 0 OSTHread bf4

Scan Thread 14 OSTHread 670

Scan Thread 15 OSTHread 17d8

Scan Thread 16 OSTHread 1930

Scan Thread 17 OSTHread 1e08

Scan Thread 29 OSTHread 1324

DOMAIN(04FFE508):HANDLE(Pinned):16212f0:Root: 08dfd080(System.Object[])->

07f370b4(Infragistics.Silverlight.DragDropManager)->

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------

We are setting up the drag drop on the Loaded events of various elements in DataTemplates e.g:

 

private void ClassDataTemplateBorder_Loaded(object sender, RoutedEventArgs e)

{

(sender

as Border).Loaded -= ClassDataTemplateBorder_Loaded;

 

DragSource dragSource = new DragSource { IsDraggable = true };

dragSource.Drop -= DragSource_Drop;
dragSource.Drop += DragSource_Drop;
dragSource.DragStart -= DragSource_DragStart;
dragSource.DragStart += DragSource_DragStart;

DragDropManager.SetDragSource(sender as Border, dragSource);

}

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Are there known memory leaks with either the Drag drop framework or XamWebTileView?

Parents
  • 8831
    posted

    Hi deta,

    It's possible because the DragSource/DropTarget instance keeps reference of the UIElement it is attached to. When the dragged object is destroyed (the data is removed from collection and that will produce that the UIElement is removed) you need to detach from this UIElement the previously attached DragSource or DropTarget instances.

    When DragEnd event is fired your event handler needs to contains these two lines (the second one is needed only when the same UIElement is also used as drop target)

     

    private void OnDragEnd(object sender, DragDropEventArgs e)

    {

        DragDropManager.SetDragSource(e.DragSource, null);

        DragDropManager.SetDropTarget(e.DragSource, null);

    }

     

    There is known leak that’s fixed but the fix will be available with next service release. After the detaching there will be one instance still standing captured.

    What you can do now is to put this line of code next to the previous two lines in DragEnd event handler:

        

        ...

        DragDropManager.DragPopup.Child = null;

    } 

    That should fix the leaks but if there are still instances alive, after the detaching and popup’s child clean-up, let me know and I’ll try to track them.

    Best regards.

Reply Children