How can i trap a Windows system message (like WM_SETTEXT) that was sent by some window (VLC player window in my case)? I've tried to inherit NativeWindow class and override WndProc like this:

class VLCFilter : NativeWindow
{
    System.IntPtr iHandle;
    const int WM_SETTEXT = 0x000C;

    public VLCFilter()
    {
        Process p = Process.GetProcessesByName("vlc")[0];
        iHandle = p.MainWindowHandle;
    }

    protected override void WndProc(ref Message aMessage)
    {
        base.WndProc(ref aMessage);

        if (aMessage.HWnd != iHandle)
        return false;

        if (aMessage.Msg == WM_SETTEXT)
        {
            MessageBox.Show("VLC window text changed!");
        }
    }
}

I have checked with Microsoft Spy++ that WM_SETTEXT message is sent by VLC player but my code doesn't seem to get the work done. I've refered mainly to: http://www.codeproject.com/kb/dotnet/devicevolumemonitor.aspx

I'm trying to make this work for some time with no success. What am I doing wrong? What I am not doing? Maybe there is easier way to do this?

My initial goal is to catch when VLC player (that could be playing somewhere in the background and is not emmbed in my application) repeats its playback (have noticed that WM_SETTEXT message is sent then and I'm trying to find it out like this).