Question

I want to cause all open popups (with StaysOpen == false) to close from code. Basically I want to simulate the user clicking the mouse (which would close the popups) from code.

I don’t need to actually simulate the click, I just need the resulting behavior. I’ve thought about just going through the visual tree looking for popups and closing each one, but that doesn’t seem like the cleanest approach.

Thanks in advance for any help or opinions.

Answer 1

A WPF popup actually creates a new window (a Win32 window, not a WPF Window instance). So you can’t find it in the Application.Windows collection, but you can probably find it using a Win32 API like EnumChildWindows.

Once you have the handle, you can retrieve the associated HwndSource. I think the RootVisual of the HwndSource is the Popup (didn’t check, you might have to look deeper in the visual tree).

So the code should be similar to this (completely untested):

public static class PopupCloser
{
    public static void CloseAllPopups()
    {
        foreach(Window window in Application.Current.Windows)
        {
            CloseAllPopups(window);
        }
    }

    public static void CloseAllPopups(Window window)
    {
        IntPtr handle = new WindowInteropHelper(window).Handle;
        EnumChildWindows(handle, ClosePopup, IntPtr.Zero);
    }

    private static bool ClosePopup(IntPtr hwnd, IntPtr lParam)
    {
        HwndSource source = HwndSource.FromHwnd(hwnd);
        if (source != null)
        {
            Popup popup = source.RootVisual as Popup;
            if (popup != null)
            {
                popup.IsOpen = false;
            }
        }
        return true; // to continue enumeration
    }

    private delegate bool EnumWindowsProc(IntPtr hwnd, IntPtr lParam);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool EnumChildWindows(IntPtr hwndParent, EnumWindowsProc lpEnumFunc, IntPtr lParam);

}