Problem with remotly turn on/off monitor

[emhiil]

Hi!

I'm trying to remotly turn on/off my monitor using this code below. The problem is whenever I call the method that turn on/off the monitor from within the tcp asynchronous receive data method, the application just ends with no exception. So i put in a delegate but the same problem was still there.

What is the correct way of doing this?

public delegate void SendMessageCallback(int hWnd, int hMsg, int wParam, int lParam);
 
public int WM_SYSCOMMAND = 0x0112;
public int SC_MONITORPOWER = 0xF170;
 
[DllImport("user32.dll")]
private static extern int SendMessage(int hWnd, int hMsg, int wParam, int lParam);

public void OnDataReceived(IAsyncResult asyn)
{
    SocketPacket socketData = (SocketPacket)asyn.AsyncState;
 
    try
    {
        int iRx  = socketData.currentSocket.EndReceive(asyn);
        char[] chars = new char[iRx + 1];
 
        Decoder d = Encoding.UTF8.GetDecoder();
        int charLen = d.GetChars(socketData.dataBuffer, 0, iRx, chars, 0);
 
        String szData = new String(chars);
 
        if (szData.ToString().Substring(0, 4) == "1040")
        {
            SendMonitorMessage(this.Handle.ToInt32(), WM_SYSCOMMAND, SC_MONITORPOWER, 2);
        }
    }
    catch { }
}

private void SendMonitorMessage(int hWnd, int hMsg, int wParam, int lParam)
{
    if (InvokeRequired)
    {
        this.Invoke(new SendMessageCallback(this.OnSendMonitorMessage), new object[] { hWnd, hMsg, wParam, lParam });
    }
    else
    {
        this.OnSendMonitorMessage(hWnd, hMsg, wParam, lParam);
    }
}
 
private void OnSendMonitorMessage(int hWnd, int hMsg, int wParam, int lParam)
{
    SendMessage(hWnd, hMsg, wParam, lParam);
}

[Christian Binder]

Did you try using breakpoints an look whats happening?
Maybe you also take a look into window's error-log/event-viewer.