using System . Runtime . InteropServices;
[ DllImport ( "user32.dll" )]
public static extern IntPtr WindowFromDC( IntPtr hDC);
private void button1_Click( object sender , EventArgs e)
{
Graphics vGraphics = Graphics . FromHwnd(Handle);
Control vControl = Control . FromHandle(WindowFromDC(vGraphics . GetHdc()));
if (vControl != null ) MessageBox . Show(vControl . Name);
}