Will the WPF user Control be Disposed if used inside a Windows Form that will be disposed?

Question

So I just learned that we can put a WPF UserControl to a windows Form using ElementHost control. If that windows form control was disposed, will the WPF user control be disposed too?

Answer 1

If your WPF UserControl is IDisposable the answer is yes, otherwise no.

In the source code for Dispose method of ElementHost class which hosts a WPF UserControl, you can see this:

IDisposable child = this.Child as IDisposable;
if (child != null)
{
    child.Dispose();
}

Which means the Child will be disposed, if it's IDisposable.

Note

WPF doesn't rely on IDisposable interface for resource cleanup. But since the UserControl will be used in a Windows Forms Project in an ElementHost control which supports IDisposable pattern, you can rely on IDisposable pattern if you need to perform some resource clean up. But if it was a WPF project, you should use WPF mechanisms for resource clean up.