c# - C#如何获取Windows监视器名称

Question

我正在尝试制作一个显示所有显示器和监视器名称的函数。但是我第二次调用 enumDisplayDevices 时，如果第一个参数是 lpDisplayDevice.DeviceName，则会出现错误。我知道这是第一个参数，因为如果它设置为“IntPtr.Zero”，则没有错误。

我找不到另一个如何在 C# 中执行此操作的示例。

    public static void show_display_devices()
    {
        DISPLAY_DEVICE lpDisplayDevice = new DISPLAY_DEVICE(0);     // OUT
        int devNum = 0;
        while(true)
        {
            bool success = EnumDisplayDevices( IntPtr.Zero,  devNum,  ref lpDisplayDevice,  0);
            if( !success )
                break;

            Console.WriteLine("\ndevNum =" + devNum);
            Console.WriteLine("cb =" + lpDisplayDevice.cb);
            Console.WriteLine("DeviceID =" + lpDisplayDevice.DeviceID);
            Console.WriteLine("DeviceKey =" + lpDisplayDevice.DeviceKey);
            Console.WriteLine("DeviceName =" + lpDisplayDevice.DeviceName.Trim());
            Console.WriteLine("DeviceString =" + lpDisplayDevice.DeviceString.Trim());
            // Show monitor name:
            DISPLAY_DEVICE monitor_name = new DISPLAY_DEVICE(0);        // OUT

               >>>>>>>>>>>   NEXT LINE HAS ERROR:  <<<<<<<<<<<<<<<
            EnumDisplayDevices(lpDisplayDevice.DeviceName, 0, ref monitor_name, 0);  <<<<<<<<<<<<<<<<<  "lpDisplayDevice.DeviceName" causes error  <<<<<<
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^ - CAUSES ERROR <<<<<<

            Console.WriteLine("Monitor name =" + lpDisplayDevice.DeviceString.Trim());

            ++devNum;
        }
    }

Answer 1

问题出在声明“private static extern bool EnumDisplayDevices()”中。我将 lpDevice 从 IntPtr 更改为字符串，它对我有用。

下面的源代码在“输出”窗口中生成以下内容：

devNum =0 cb =424 DeviceID =PCI\VEN_10DE&DEV_0402&SUBSYS_0440196E&REV_A1 DeviceKey =\Registry\Machine\System\CurrentControlSet\Control\Video{B757E378-AF2E-4826-BA9E-927C5B81B139}\0000 DeviceName =\.\DISPLAY1 DeviceString =NVIDIA GeForce 86线程“RunPowerStatusMonitor 线程”(0x2108) 已退出，代码为 0 (0x0)。监视器名称 = 通用 PnP 监视器

devNum =1 cb =424 DeviceID =PCI\VEN_10DE&DEV_0402&SUBSYS_0440196E&REV_A1 DeviceKey =\Registry\Machine\System\CurrentControlSet\Control\Video{B757E378-AF2E-4826-BA9E-927C5B81B139}\0001 GTName =\.\DISPLAY2 DeviceString =NVIDIA GeForce 86监视器名称 = 通用 PnP 监视器

        public static void show_display_devices()
    {
        DISPLAY_DEVICE lpDisplayDevice = new DISPLAY_DEVICE(0);     // OUT
            DISPLAY_DEVICE monitor_name = new DISPLAY_DEVICE(0);        // OUT

        int devNum = 0;
        while (EnumDisplayDevices(null, devNum, ref lpDisplayDevice, 0))
        {

            Console.WriteLine("\ndevNum =" + devNum);
            Console.WriteLine("cb =" + lpDisplayDevice.cb);
            Console.WriteLine("DeviceID =" + lpDisplayDevice.DeviceID);
            Console.WriteLine("DeviceKey =" + lpDisplayDevice.DeviceKey);
            Console.WriteLine("DeviceName =" + lpDisplayDevice.DeviceName.Trim());
            Console.WriteLine("DeviceString =" + lpDisplayDevice.DeviceString.Trim());
            // Show monitor name:



            EnumDisplayDevices( lpDisplayDevice.DeviceName, 0, ref monitor_name, 0);
            Console.WriteLine("Monitor name =" + monitor_name.DeviceString.Trim());

            ++devNum;
        }
    }

    [DllImport("User32.dll")]
    private static extern bool EnumDisplayDevices(
        string lpDevice, int iDevNum,
        ref DISPLAY_DEVICE lpDisplayDevice, int dwFlags);




    [StructLayout(LayoutKind.Sequential)]
    public struct DISPLAY_DEVICE
    {
        public int cb;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
        public string DeviceName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
        public string DeviceString;
        public int StateFlags;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
        public string DeviceID;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
        public string DeviceKey;

        public DISPLAY_DEVICE(int flags)
        {
            cb = 0;
            StateFlags = flags;
            DeviceName = new string((char)32, 32);
            DeviceString = new string((char)32, 128);
            DeviceID = new string((char)32, 128);
            DeviceKey = new string((char)32, 128);
            cb = Marshal.SizeOf(this);
        }
    }