Why is this DataGridView still referenced by a UserPreferenceChangedEventHandler?

Question

I upgraded a .NET 2.0 Winform Application build with VS2005 to .NET 3.5 SP1. build by VS 2008

The application had a memory leak in .NET 2.0 caused by a ToolStripControl that was referenced by a UserPreferenceChangedEventHandler.

Upgrading to .NET 3.5 fixed the issue. I still have a problem with DataGridViews.

They are also referenced by a UserPreferenceChangedEventHandler.

Are there some common problems with DataGridViews that prevent forms containing them not being recycled by the garbage collector?

Instance Retention Graph

Answer 1

For anything implementing IDisposable you should call Dispose(). DataGridView is one of those... which in turn ensures that it unregisters the static event handler you mention...