send display to sleep mode in c#
<p>it's a standard windows function that the display goes into sleep mode after the configured time. is it somehow possible to send the display into sleep mode immediately from a c# .net application in windows 7? i've already tried one thing i found but it didn't work for me.</p>

<pre><code>[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

[DllImport("user32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
public static extern IntPtr GetDesktopWindow();

private const int SC_MONITORPOWER = 0xF170;
private const UInt32 WM_SYSCOMMAND = 0x0112;
private const int MONITOR_ON = -1;
private const int MONITOR_OFF = 2;
private const int MONITOR_STANBY = 1;

public static void DisplayToSleep()
{
    var hWnd = GetDesktopWindow();
    var ret = SendMessage(hWnd , Constants.WM_SYSCOMMAND, (IntPtr)Constants.SC_MONITORPOWER, (IntPtr)Constants.MONITOR_OFF);
}
</code></pre>

<p>hWnd seems to have a valid value but ret is always 0.</p>

<p>thx, kopi_b</p>
