NativeFloatingWindow can't be cleared bug

[wuyang26]

with windows10 system,VS2017,and .net 4.5,run the "QuickStart" project ,drag one panel to show a separate window(NativeFloatingWindow object),minimized the main window ,then maximized the main window,drag and drop the separate NativeFloatingWindow to dock,at last the NativeFloatingWindow can't be cleared.
another,
Every time ,drag one panel to show a separate window,and then go back docking,but monitor the visual tree,the NativeFloatingWindow object more and more,it can't be destroid.

[weifenluo]

A DockItem can have two docking state: docked and floating, you can double click to switch between these two states. Therefore two states must be preserved. For simplicity, the floating window will be hidden instead of being destroyed when all DockItem objects are docked.
The first behavior is definitely a bug, it looks like the data binding between NativeFloatingWindow.Visibility and FloatingWindow.IsVisible are broken (Line 29-34 in NativeFloatingWindow.xaml).

[weifenluo]

OK, the root cause is when min/max window, the Window.Visibility dependency property is set with a local value, therefore breaks the data binding.

To verify, add a Debug.WriteLine at NativeFloatingWindow.cs line 150:

                case WM_NCLBUTTONDOWN:
                    Debug.WriteLine(string.Format("FloatingWindow.IsVisible={0}, this.Visibility={1}, this.Visibility.LocalValue={2}", FloatingWindow.IsVisible, this.Visibility, this.ReadLocalValue(VisibilityProperty)));

This will output debug info when clicking the window caption.
Output before window min/maxed:

FloatingWindow.IsVisible=True, this.Visibility=Visible, this.Visibility.LocalValue={DependencyProperty.UnsetValue}

Output after window min/maxed:

FloatingWindow.IsVisible=True, this.Visibility=Visible, this.Visibility.LocalValue=Visible

[wuyang26]

Thank your reply! I know the two docking state,By double click to switch between these two states,the NativeFloatingWindow object don’t increase，but using drag and drop the same panel to switch between these two states,the NativeFloatingWindow object increase more and more(Operate repeat 3 times at last). you can update the .net 4.5,then run and check the real-time Visual studio's visual tree

[wuyang26]

Another,with the .NET 4.5 update ,the project "WindowDockSample" compile error.

[weifenluo]

Thanks for reporting the bug. It's been fixed and this issue is closed.

I can't reproduce the compile error, please open another issue with detailed error message.