Screen On/Off

Jacob Saylor

I'm currently dabbling into digital signage and I'm having troubles with a monitor turning off on me. My question is this : is there a way in C# code that I can tell if a monitor is currently on or off? I'm writing an alert system for me since I cannot correct the monitor's issue at this time.

I've tried looking into system.manager, system.environment, and systeminformation... but was unable to find anything which was able to tell me the monitor's current state.

Specs:
Monitor : Samsung TV
PC: Windows XP PRO 32-bit

3 Replies

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naura pax16y ago
Accepted answer
hi,
you need to define this function in your form class also .
//add this line at the top: using System.Runtime.InteropServices;
[DllImport("Kernel32.DLL", CharSet = CharSet.Auto,
       SetLastError=true)]
private extern static
      bool GetDevicePowerState(
          IntPtr hDevice,
          out bool fOn);

then call this function in your program, the return value of false (for fOn) means monitor is turned off, you'll need to pass the handle of the monitor device to this method ex.
public static void Main(String[] args)
{
bool fOn;
IntPtr hDC = PlatformInvokeUSER32.GetDC(PlatformInvokeUSER32.GetDesktopWindow());
   if(GetDevicePowerState(Intptr,out fOn))
Consol.WriteLine("Off");
}
please check this cause i'm not so sure about how to get window handle.
0
wejden khaldi14y ago
Hi, i use your function but i get the same resut for availability when i close the monitor. i just testing witg a pc monitor not a TV.
Can you help me plz
0
Jacob Saylor16y ago
I found this bit of code... Your response pointed me in the correct path. Thank you so much!

private int getDisplayStatus()
        {
            int status = 0;

            SelectQuery query = new SelectQuery("SELECT Availability, DeviceID, ScreenHeight , ScreenWidth, Bandwidth FROM Win32_DesktopMonitor");

            using( ManagementObjectSearcher searcher = new
            ManagementObjectSearcher(query))
            {
                foreach(ManagementObject mo in searcher.Get())
                {
                    Console.WriteLine("{0}, {1}, {2} - {3}",
                    mo.Properties["DeviceID"].Value.ToString(),
                    mo.Properties["Availability"].Value.ToString(), // WMI docs for possible values 3 is running full power
                    mo.Properties["ScreenHeight"].Value.ToString(),
                    mo.Properties["ScreenWidth"].Value.ToString());
                }
            }
            return status;
        }
+1