获取屏幕中某个点的RGB值与CAD屏幕像素值

'获取CAD屏幕像素的比值

Function ViewScreen() As Double
    Dim ScreenSize As Variant
    ScreenSize = ThisDrawing.GetVariable("screensize") '当前视口的屏幕宽度和高度
    Dim H As Variant
    H = ThisDrawing.GetVariable("viewsize") '当前视图图形的实际高度
    ViewScreen = Abs(H / ScreenSize(1))
End Function
Public Declare Function GetCursorPos Lib "user32" (lpPoint As POINTAPI) As Long

获取屏幕中某个点的RGB值

 public static Color GetColor()
        {
            POINT _Point = new POINT();
            GetCursorPos(ref _Point);
            IntPtr _Hwnd = WindowFromPoint((uint)_Point.x, (uint)_Point.y);
            IntPtr _DC = GetDC(_Hwnd);
            ScreenToClient(_Hwnd, ref _Point);
            uint _ColorLong = GetPixel(_DC, _Point.x, _Point.y);
            Color _Color = Color.FromArgb((int)_ColorLong & 0xFF, (int)(_ColorLong & 0xFF00) / 256, (int)(_ColorLong & 0xFF0000) / 65536); 

            ReleaseDC(_Hwnd, _DC); 

            return _Color; 

        } 

        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            public int x;
            public int y;
        }
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC); 

        [DllImport("gdi32.dll")]
        public static extern uint GetPixel(IntPtr hDC, int XPos, int YPos); 

        [DllImport("user32.dll")]
        public static extern uint ScreenToClient(IntPtr hwnd, ref POINT p_Point); 

        [DllImport("user32.dll")]
        public static extern bool GetCursorPos(ref POINT p_Point); 

        [DllImport("user32.dll")]
        public static extern IntPtr WindowFromPoint(uint x_point, uint y_point); 

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern IntPtr GetDC(IntPtr hWnd);