public class MyForm : Form
{
// ..
[ DllImport( "User32.dll" ) ]
private static extern IntPtr SendMessage( IntPtr hWnd, uint msg, UIntPtr wParam, IntPtr lParam );
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_SCREENSAVE = 0xF140;
public void RunScreenSaver( )
{
SendMessage( this.Handle, WM_SYSCOMMAND, ( UIntPtr )SC_SCREENSAVE, IntPtr.Zero );
}
}