问使用PInvoke更改窗口大小不会导致工作区更新

EN

foreach (var process in Process.GetProcessesByName("magic string"))
{
    var h = process.MainWindowHandle;

    if (h == IntPtr.Zero)
        continue;

    GetWindowRect(h, out RECT rect);

    //define new window size
    int width = 646;
    int height = 509;

    MoveWindow(h, rect.Left, rect.Top, width, height, true);
    
    //working solution, but not visually ideal
    ShowWindow(h, ShowWindowCommands.Minimize);
    ShowWindow(h, ShowWindowCommands.Restore);

    //note: none of the below methods that attempt to force update work
    //(i.e. does not visibly scale the client area)

    //RedrawWindow attempts
    RedrawWindow(h, IntPtr.Zero, IntPtr.Zero, RedrawWindowFlags.EraseNow);
    RedrawWindow(h, IntPtr.Zero, IntPtr.Zero, RedrawWindowFlags.UpdateNow);
    RedrawWindow(h, IntPtr.Zero, IntPtr.Zero, RedrawWindowFlags.Invalidate);

    //SetWindowPos attempts
    SetWindowPos(h, IntPtr.Zero, rect.Left, rect.Top, width, height, SetWindowPosFlags.SWP_SHOWWINDOW);
    SetWindowPos(h, IntPtr.Zero, rect.Left, rect.Top, width, height, SetWindowPosFlags.SWP_DRAWFRAME);

    //send WM_PAINT
    SendMessage(h, WM_PAINT, IntPtr.Zero, IntPtr.Zero);

    //@dxiv's suggestion
    RedrawWindow(h, IntPtr.Zero, IntPtr.Zero, RedrawWindowFlags.Invalidate);
    RedrawWindow(h, IntPtr.Zero, IntPtr.Zero, RedrawWindowFlags.Erase);

    //@NetMage's suggestion
    UInt32 lParam = 0;
    lParam = (UInt32)((UInt16)height << 16 | (UInt16)width);
    SendMessage(h, WM_SIZE, IntPtr.Zero, new IntPtr(lParam));

    //@Drake Wu - MSFT's suggestion
    SetWindowPos(h, IntPtr.Zero, rect.Left, rect.Top, width, height, SetWindowPosFlags.SWP_FRAMECHANGED);
}

[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
    public int Left;
    public int Top;
    public int Right;
    public int Bottom;
}

[DllImport("user32.dll", SetLastError = true)]
static extern bool GetWindowRect(IntPtr hwnd, out RECT lpRect);

[DllImport("user32.dll", SetLastError = true)]
static extern bool MoveWindow(IntPtr hWnd, int X, int Y, int Width, int Height, bool Repaint);

private enum ShowWindowCommands : int
{
    Hide = 0,
    Normal = 1,
    ShowMinimized = 2,
    Maximize = 3, 
    ShowMaximized = 3,
    ShowNoActivate = 4,
    Show = 5,
    Minimize = 6,
    ShowMinNoActive = 7,
    ShowNA = 8,
    Restore = 9,
    ShowDefault = 10,
    ForceMinimize = 11
}

[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, ShowWindowCommands nCmdShow);

[Flags]
private enum RedrawWindowFlags : uint
{
    Invalidate = 0x1,
    InternalPaint = 0x2,
    Erase = 0x4,
    Validate = 0x8,
    NoInternalPaint = 0x10,
    NoErase = 0x20,
    NoChildren = 0x40,
    AllChildren = 0x80,
    UpdateNow = 0x100,
    EraseNow = 0x200,
    Frame = 0x400,
    NoFrame = 0x800
}

[DllImport("user32.dll")]
static extern bool RedrawWindow(IntPtr hWnd, IntPtr lprcUpdate, IntPtr hrgnUpdate, RedrawWindowFlags flags);

[Flags]
private enum SetWindowPosFlags : uint
{
    SWP_ASYNCWINDOWPOS = 0x4000,
    SWP_DEFERERASE = 0x2000,
    SWP_DRAWFRAME = 0x0020,
    SWP_FRAMECHANGED = 0x0020,
    SWP_HIDEWINDOW = 0x0080,
    SWP_NOACTIVATE = 0x0010,
    SWP_NOCOPYBITS = 0x0100,
    SWP_NOMOVE = 0x0002,
    SWP_NOOWNERZORDER = 0x0200,
    SWP_NOREDRAW = 0x0008,
    SWP_NOREPOSITION = 0x0200,
    SWP_NOSENDCHANGING = 0x0400,
    SWP_NOSIZE = 0x0001,
    SWP_NOZORDER = 0x0004,
    SWP_SHOWWINDOW = 0x0040,
}

[DllImport("user32.dll", SetLastError = true)]
static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, SetWindowPosFlags uFlags);

private const int WM_PAINT = 0x000F;
private const int WM_SIZE = 0x0005;

[DllImport("user32.dll")]
public static extern Int64 SendMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);