C# 设置和读取屏幕模式(复制，扩展等)

    public class ScreenDisplaySetting
    {
        private const uint SDC_APPLY = 0x00000080;

        private const uint SDC_TOPOLOGY_INTERNAL = 0x00000001;

        private const uint SDC_TOPOLOGY_CLONE = 0x00000002;

        private const uint SDC_TOPOLOGY_EXTERNAL = 0x00000008;

        private const uint SDC_TOPOLOGY_EXTEND = 0x00000004;

        [DllImport("", CharSet = )]
        private static extern long SetDisplayConfig(uint numPathArrayElements, IntPtr pathArray, uint numModeArrayElements, IntPtr modeArray, uint flags);


        [DllImport("")]
        public static extern Int32 GetDisplayConfigBufferSizes(UInt32 Flags,
                out UInt32 NumPathArrayElements, out UInt32 NumModeInfoArrayElements);

        [DllImport("")]
       public static extern Int32 QueryDisplayConfig(UInt32 Flags,
       [In, Out] ref UInt32 NumPathArrayElements, IntPtr pPathInfoArray,
       [In, Out] ref UInt32 NumModeInfoArrayElements, IntPtr pModeInfoArray,
       out UInt32 CurrentTopologyId);

        /// <summary>
        /// 设置屏幕的显示模式
        /// </summary>
        /// <param name="type">模式(0 - 主屏  1 - 双屏复制  2 - 双屏扩展  3 - 第二屏幕</param>
        /// <returns></returns>
        public static void SetScreenMode(int type)
        {
            uint smode;
            [] screens = ;
            //其他屏幕显示,这里假设有2个
            var subScreen = (from o in screens where  == false select o).ToList<>();
            if ( <= 0) return;
            switch (type)
            {
                case 0:
                    smode = SDC_APPLY | SDC_TOPOLOGY_INTERNAL;
                    break;
                case 1:
                    smode = SDC_APPLY | SDC_TOPOLOGY_CLONE;//复制模式
                    break;
                case 2:
                    smode = SDC_APPLY | SDC_TOPOLOGY_EXTEND;//扩展模式
                    break;
                case 3:
                    smode = SDC_APPLY | SDC_TOPOLOGY_EXTERNAL;
                    break;
                default:
                    smode = SDC_APPLY | SDC_TOPOLOGY_INTERNAL;
                    break;
            }

            SetDisplayConfig(0, , 0, , smode);
        }

        /// <summary>
        /// 读取屏幕投影模式，读取不成功，暂不用
        /// </summary>
        public static void GetScreenMode()
        {

            UInt32 NumPathArrayElements = 0;
            UInt32 NumModeInfoArrayElements = 0;
            Int32 RetVal;

            RetVal = GetDisplayConfigBufferSizes(0, out NumPathArrayElements, out NumModeInfoArrayElements);

            IntPtr pPathArray = (4096);
            IntPtr pModeArray = (4096);

            UInt32 CurrentTopologyId = 0;

            RetVal = QueryDisplayConfig(0, ref NumPathArrayElements, pPathArray, ref NumModeInfoArrayElements, pModeArray, out CurrentTopologyId);
        
        }

    }