如何隐藏所有者最小化后显示的拥有窗口？

Question

I know about the contract between Owned windows and their Owner and that the Owned windows are hidden when the Owner is hidden. This is actually what I want. The problem is that if you show an Owned window after the Owner window is minimized then the Owned window is not hidden but is displayed normally on screen. In this case the WindowState of the Window is Minimized at start up so any Owned window that is shown is displayed on screen.

I know that I can call ShowOwnedPopups to force the OS to hide all the Owned windows but this only seems to work after the Owned window has actually been shown so you get a flicker on screen. I have tried explicitly hiding the window (eg removing the WS_VISIBLE bit or trying to alter the WM_SHOWCOMMAND such that it is shown hidden) but then the Owned window is not made visible when the Owner is restored. This is consistent with the documentation for the ShowOwnedPopups API whereby the only windows that are made visible are those hidden by the ShowOwnedPopups call.

So I'm looking for some way to either have the OS show the window in such a way that it is not made visible to the end user until the Owner is restored -or- a way to set a flag on the window so that the OS thinks it hid the window using ShowOwnedPopups and then I will manually hide the window and set that flag.

Note, the code that is showing the Owned windows isn't associated with the shell so it's not a simple matter of not showing the owned window until the owner is restored. This is part of a separate custom control and in this case it happens to be a WPF control so the control could even be used in an ElementHost so I can't just watch for the WindowState of the owning window either. Any windows API solution is welcomed though.

Answer 1

As a little dirty trick (which i have used previously at one of my projects), I suggest creating the window outside of the visible area, minimize and move its position to visible area again when it is minimized. Check the code below.

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    var w = new Window();   // Create window
    w.Owner = this;         // Set this window as owner
    w.WindowStartupLocation = System.Windows.WindowStartupLocation.Manual; // Set startup location as manual
    w.Left = -10000;        // Set x position to -10000 (or anything which makes it out of bounds)
    w.Top = -10000;         // Set y position to -10000
    w.Show();               // Show window (it will not be shown, not even blink)
    w.WindowState = System.Windows.WindowState.Minimized;   // Set window as minimized
    w.Left = 100;           // Set x position to 100 (or whatever you want)
    w.Top = 100;            // Set y position to 100 (or whatever you want)
}