HDMI TV sometimes not detected in windows 7? Possible to invoke Detect in code?

Question

i have a standalone public kiosk pc that startups automatically everyday. It is connected to a HD TV and sometimes it is not detected. i have to personally go down to the PC, go to Screen Resolution and press Detect which it works.

my question is how do i know if the monitor i want it to display is connected properly in code?

thanks

Answer 1

I did manage to find some code on the MSDN site where a user is using code to determine which type of monitor is connected. I hope this may be a good starting point for you.

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;

namespace CRT
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public class NativeMethods

        {
            [DllImport("user32.dll", EntryPoint = "MonitorFromWindow", SetLastError = true)]
            public static extern IntPtr MonitorFromWindow(
                [In] IntPtr hwnd, uint dwFlags);

            [DllImport("dxva2.dll", EntryPoint = "GetNumberOfPhysicalMonitorsFromHMONITOR", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool GetNumberOfPhysicalMonitorsFromHMONITOR(
                IntPtr hMonitor, ref uint pdwNumberOfPhysicalMonitors);

            [DllImport("dxva2.dll", EntryPoint = "GetPhysicalMonitorsFromHMONITOR", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool GetPhysicalMonitorsFromHMONITOR(
                IntPtr hMonitor,
                uint dwPhysicalMonitorArraySize,
                [Out] NativeStructures.PHYSICAL_MONITOR[] pPhysicalMonitorArray);

            [DllImport("dxva2.dll", EntryPoint = "DestroyPhysicalMonitors", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool DestroyPhysicalMonitors(
                uint dwPhysicalMonitorArraySize, [Out] NativeStructures.PHYSICAL_MONITOR[] pPhysicalMonitorArray);

            [DllImport("dxva2.dll", EntryPoint = "GetMonitorTechnologyType", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool GetMonitorTechnologyType(
                IntPtr hMonitor, ref NativeStructures.MC_DISPLAY_TECHNOLOGY_TYPE pdtyDisplayTechnologyType);

            [DllImport("dxva2.dll", EntryPoint = "GetMonitorCapabilities", SetLastError = true)]
            [return: MarshalAs(UnmanagedType.Bool)]
            public static extern bool GetMonitorCapabilities(
                IntPtr hMonitor, ref uint pdwMonitorCapabilities, ref uint pdwSupportedColorTemperatures);
        }

        public class NativeConstants
        {
            public const int MONITOR_DEFAULTTOPRIMARY = 1;

            public const int MONITOR_DEFAULTTONEAREST = 2;

            public const int MONITOR_DEFAULTTONULL = 0;
        }

        public class NativeStructures
        {
            [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
            public struct PHYSICAL_MONITOR
            {
                public IntPtr hPhysicalMonitor;

                [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)] public string szPhysicalMonitorDescription;
            }

            public enum MC_DISPLAY_TECHNOLOGY_TYPE
            {
                MC_SHADOW_MASK_CATHODE_RAY_TUBE,

                MC_APERTURE_GRILL_CATHODE_RAY_TUBE,

                MC_THIN_FILM_TRANSISTOR,

                MC_LIQUID_CRYSTAL_ON_SILICON,

                MC_PLASMA,

                MC_ORGANIC_LIGHT_EMITTING_DIODE,

                MC_ELECTROLUMINESCENT,

                MC_MICROELECTROMECHANICAL,

                MC_FIELD_EMISSION_DEVICE,
            }
        }

        public Window1() { InitializeComponent(); }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            WindowInteropHelper helper = new WindowInteropHelper(this);

            IntPtr hMonitor = NativeMethods.MonitorFromWindow(helper.Handle, NativeConstants.MONITOR_DEFAULTTOPRIMARY);
            int lastWin32Error = Marshal.GetLastWin32Error();

            uint pdwNumberOfPhysicalMonitors = 0u;
            bool numberOfPhysicalMonitorsFromHmonitor = NativeMethods.GetNumberOfPhysicalMonitorsFromHMONITOR(
                hMonitor, ref pdwNumberOfPhysicalMonitors);
            lastWin32Error = Marshal.GetLastWin32Error();

            NativeStructures.PHYSICAL_MONITOR[] pPhysicalMonitorArray =
                new NativeStructures.PHYSICAL_MONITOR[pdwNumberOfPhysicalMonitors];
            bool physicalMonitorsFromHmonitor = NativeMethods.GetPhysicalMonitorsFromHMONITOR(
                hMonitor, pdwNumberOfPhysicalMonitors, pPhysicalMonitorArray);
            lastWin32Error = Marshal.GetLastWin32Error();

            uint pdwMonitorCapabilities = 0u;
            uint pdwSupportedColorTemperatures = 0u;
            var monitorCapabilities = NativeMethods.GetMonitorCapabilities(
                pPhysicalMonitorArray[0].hPhysicalMonitor, ref pdwMonitorCapabilities, ref pdwSupportedColorTemperatures);
            lastWin32Error = Marshal.GetLastWin32Error();

            NativeStructures.MC_DISPLAY_TECHNOLOGY_TYPE type =
                NativeStructures.MC_DISPLAY_TECHNOLOGY_TYPE.MC_SHADOW_MASK_CATHODE_RAY_TUBE;
            var monitorTechnologyType = NativeMethods.GetMonitorTechnologyType(
                pPhysicalMonitorArray[0].hPhysicalMonitor, ref type);
            lastWin32Error = Marshal.GetLastWin32Error();

            var destroyPhysicalMonitors = NativeMethods.DestroyPhysicalMonitors(
                pdwNumberOfPhysicalMonitors, pPhysicalMonitorArray);
            lastWin32Error = Marshal.GetLastWin32Error();

            this.lbl.Content = type;
        }
    }
}