Custom window reports incorrect size and mouse coordinates after maximize

[al6uiz]

1. The window size is incorrect after maximizing the custom window.
2. The coordinates of the mouse event are incorrect, which can be detected using the Slider control (min pos or max pos click)

add code in MewUI-main\samples\MewUI.Gallery\CustomWindowSample.cs line 125
new Slider().Minimum(0).Maximum(10).Margin(20).OnMouseDown(e => Debug.WriteLine(e.ScreenPosition.X))

it is gif
2.zip

Originally posted by @Charltsing in #81 (comment)