Solve WPF nested sub-window resizing the window when the flicker problem

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This link: https://blog.csdn.net/WPwalter/article/details/102775135

Because the Win32 window handle is passed across process, it can be used to achieve inter-process UI. However, this article will not talk about specific cross-process UI will only mention a significant and ease of implementation, the way the use of child windows.

You may use after the child window, found the drag resize the window when the contents of the child window flashing. If you have encountered such a problem, then just read this article to resolve.

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problem

You can look at this dynamic figure below, feel the window flashing:

In fact, when dragging the window, it is always in a flash, but each flash is very fast, gif interception when less than cut.

If you want to actually run a race to see the project, you can use the following code:

• walterlv.demo/Walterlv.Demo.HwndWrapping/Walterlv.Demo.HwndWrapping at a88f81477756af2913349970ba2f0bbab01aaf88 · walterlv/walterlv.demo

I have looked at the code extracted a submission, if you want to try, you can not use masterbranches because masterbranch fixes flicker problem.

Later use CreateWindowExto create a pure Win32 window, this flickering is more likely to be shot:

solve

    public class HwndWrapper : HwndHost
    {
        protected override HandleRef BuildWindowCore(HandleRef hwndParent)
        {
            const int WS_CHILD = 0x40000000;
++          const int WS_CLIPCHILDREN = 0x02000000;
            var owner = ((HwndSource)PresentationSource.FromVisual(this)).Handle;

            var parameters = new HwndSourceParameters("demo")
            {
                ParentWindow = owner,
--              WindowStyle = (int)(WS_CHILD),
++              WindowStyle = (int)(WS_CHILD | WS_CLIPCHILDREN),
            };
            var source = new HwndSource(parameters);
            source.RootVisual = new ChildPage();
            return new HandleRef(this, source.Handle);
        }

        protected override void DestroyWindowCore(HandleRef hwnd)
        {
        }
    }

the reason

We are exploring ......

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Reference material

• wpf - Custom dwm drawn window frame flickers on resizing if the window contains a HwndHost element - Stack Overflow
• WPF UI exploring multi-process (Like Chrome) - Jane books
• WS_CLIPSIBLINGS WS_CLIPCHILDREN and understanding of the (personally believe it is fairly comprehensive) - helloj2ee - blog Park

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