Is there any way to have a click through window?

[NickeManarin]

I want to have a click-through window, similar to having <Window AllowsTransparency="True" Background="{x:Null}"> in WPF, so that only elements with opacity are clickable and anything transparent ignores clicks and lets the click go to the background stuff.

What I understand is that by having those two options, the Window uses a different GWL_EXSTYLE:

UnsafeNativeMethods.SetWindowLong(_hWnd.MakeHandleRef(this), NativeMethods.GWL_EXSTYLE, 
    new IntPtr(exStyle | NativeMethods.WS_EX_LAYERED));

And PerPixelOpacity feature is enabled, making the non client area to be hidden.

https://github.com/dotnet/wpf/blob/326c2b4861e66065e4ed1510b1a6ceab371f8026/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/InterOp/HwndTarget.cs#L2184

[dotMorten]

I've logged this issue which links to a discussion on how to do this: #235

[dotMorten]

This feature was implemented in 2.9