How to disable 3rd party event loop

Question

I use SetWinEventHook to handle 3rd party actions, for example EVENT_SYSTEM_MINIMIZESTART event.

How can I prevent this app from minimizing? I mean I need something like WinForms e.Cancel = true;

How could it work: 3rd party application is minimizing, my app capture this action, cancels it, then ask Do you really want to minimize %appname%? , then use SendMessage to minimize it if user clicks on Yes button. Here is HookCreation:

    public Hook(IntPtr hWnd)
    {
        lpfnWinEventProc = WinEvent;
        handle = GCHandle.Alloc(lpfnWinEventProc);
        pHook = SetWinEventHook((uint)SystemEvents.EVENT_MIN,
                                (uint)SystemEvents.EVENT_MAX,
                                hWnd,
                                lpfnWinEventProc,
                                0,
                                0,
                                WINEVENT_OUTOFCONTEXT
            );
        if (IntPtr.Zero.Equals(pHook))
            throw new Win32Exception();
    }

Answer 1

The only hook that allows you to filter messages is a CBT Hook . If the list of operations that are reported through this hook is not sufficient, you may find a solution by installing a GetMsgProc hook. This allows you to modify the message. Replacing appropriate incoming messages with a WM_NULL message is essentially the same as cancelling the message. This only works for messages that are posted to the message queue. Sent messages are not filtered through this hook.