1         public static Bitmap GetDesktopImage(bool cursorDisplay = false)
 2         {
 3             //In size variable we shall keep the size of the screen.  
 4             Size size = new Size();
 5             //Variable to keep the handle to bitmap.   
 6             int hBitmap;
 7             //Here we get the handle to the desktop device context.      
 8             int hDC = GetDC(GetDesktopWindow());
 9             //Here we make a compatible device context in memory for screen device context.   
10             int hMemDC = CreateCompatibleDC(hDC);
11             // We pass SM_CXSCREEN constant to GetSystemMetrics to get the X coordinates of screen.  
12             size.Width = GetSystemMetrics(SM_CXSCREEN);
13             //We pass SM_CYSCREEN constant to GetSystemMetrics to get the Y coordinates of screen.      
14             size.Height = GetSystemMetrics(SM_CYSCREEN);
15             //We create a compatible bitmap of screen size using screen device context. 
16             hBitmap = CreateCompatibleBitmap(hDC, size.Width, size.Height);
17             //As hBitmap is IntPtr we can not check it against null. For this purspose IntPtr.Zero is used.       
18             if (hBitmap != 0)
19             {
20                 //Here we select the compatible bitmap in memeory device context and keeps the refrence to Old bitmap.   
21                 int hOld = SelectObject(hMemDC, hBitmap);
22                 //We copy the Bitmap to the memory device context.     
23                 BitBlt(hMemDC, 0, 0, size.Width, size.Height, hDC, 0, 0, (int)(TernaryRasterOperations.SRCCOPY | TernaryRasterOperations.CaptureBlt));
24                 //We select the old bitmap back to the memory device context.   
25                 SelectObject(hMemDC, hOld);
26                 //We delete the memory device context.         
27                 DeleteDC(hMemDC);
28                 //We release the screen device context.   
29                 ReleaseDC(GetDesktopWindow(), hDC);
30                 //Image is created by Image bitmap handle and stored in local variable.    
31                 Bitmap bmp = System.Drawing.Image.FromHbitmap((IntPtr)hBitmap);
32                 //Release the memory to avoid memory leaks.      
33                 DeleteObject(hBitmap);
34 
35                 // 画鼠标
36                 if (cursorDisplay)
37                 {
38                     using (Graphics graphics = Graphics.FromImage(bmp))
39                     {
40                         graphics.CompositingQuality = CompositingQuality.HighSpeed;
41                         graphics.SmoothingMode = SmoothingMode.HighQuality;
42                         //graphics.CopyFromScreen(0, 0, 0, 0, new System.Drawing.Size(width, height));
43 
44                         //显示鼠标
45                         DrawMouse(graphics);
46                     }
47                 }
48 
49                 //This statement runs the garbage collector manually. 
50                 //GC.Collect();
51                 //Return the bitmap    
52                 return bmp;
53             }
54             //   If hBitmap is null retunrn null.   
55             return null;
56         }