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);