A better hook for checking new windows

[maraf]

Article:
https://www.codeproject.com/Tips/1057230/Windows-Resize-and-Move

Sources:
WindowsMover-src.zip

private readonly int windowMessage_ShellHook;
public WindowsHookForm()
{
    windowMessage_ShellHook = WindowsApi.RegisterWindowMessage("SHELLHOOK");
    WindowsApi.RegisterShellHookWindow(this.Handle);
}

public event Action<IntPtr> WindowCreatedEvent;  
public event Action<IntPtr> WindowActivatedEvent;
public event Action<IntPtr> WindowDestroyedEvent;

protected override void WndProc(ref Message message)
{
    if(message.Msg == windowMessage_ShellHook)
    {
        WindowsApi.ShellEvents shellEvent = (WindowsApi.ShellEvents)message.WParam.ToInt32();
        IntPtr windowHandle = message.LParam;

        switch(shellEvent)
        {
            case WindowsApi.ShellEvents.HSHELL_WINDOWCREATED:
                if(WindowCreatedEvent != null)
                    WindowCreatedEvent(windowHandle);
                break;
                
            case WindowsApi.ShellEvents.HSHELL_WINDOWACTIVATED:
                if(WindowActivatedEvent != null)
                    WindowActivatedEvent(windowHandle);
                break;

            case WindowsApi.ShellEvents.HSHELL_WINDOWDESTROYED:
                if(WindowDestroyedEvent != null)
                    WindowDestroyedEvent(windowHandle);
                break;
        }
    }
    base.WndProc(ref message);
}

Additional source:
https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-registershellhookwindow

[maraf]

The event messages received are only those sent to the Shell window associated with the specified window's desktop. Many of the messages are the same as those that can be received after calling the SetWindowsHookEx function and specifying WH_SHELL for the hook type. The difference with RegisterShellHookWindow is that the messages are received through the specified window's WindowProc and not through a call back procedure.

https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-setwindowshookexa

https://blogs.msdn.microsoft.com/calvin_hsia/2016/11/30/its-easy-to-use-windows-hooks-even-from-c/

[maraf]

https://www.meziantou.net/detect-the-opening-of-a-new-window-in-csharp.htm