今天无聊翻代码,翻出来一个以前写的C#截屏的函数...拿出来和大家共享一下.
这段代码是参照网上一段截屏的C++代码改写的.只不过把API都声明了一下而已.
声明的各API也附后.以供参照.如有问题欢迎指出.(Appledotnet@hotmail.com)
这段代码是参照网上一段截屏的C++代码改写的.只不过把API都声明了一下而已.
声明的各API也附后.以供参照.如有问题欢迎指出.(Appledotnet@hotmail.com)
Code
1 /**////
2 /// 截取部分屏幕
3 ///
4 /// 左上角
5 /// 右下角
6 /// 是否全屏幕
7 /// 返回值Bitmap
8 public static Bitmap GetPartScreen(Point P1,Point P2,bool Full)
9 {
10 IntPtr hscrdc,hmemdc;
11 IntPtr hbitmap,holdbitmap;
12 int nx,ny,nx2,ny2;
13 nx=ny=nx2=ny2=0;
14 int nwidth, nheight;
15 int xscrn, yscrn;
16 hscrdc = CreateDC("DISPLAY", null, null, 0);//创建DC句柄
17 hmemdc = CreateCompatibleDC(hscrdc);//创建一个内存DC
18 xscrn = GetDeviceCaps(hscrdc, GetDeviceCapsIndex.HORZRES);//获取屏幕宽度
19 yscrn = GetDeviceCaps(hscrdc, GetDeviceCapsIndex.VERTRES);//获取屏幕高度
20 if(Full)//如果是截取整个屏幕
21 {
22 nx = 0;
23 ny = 0;
24 nx2 = xscrn;
25 ny2 = yscrn;
26 }
27 else
28 {
29 nx = P1.X;
30 ny = P1.Y;
31 nx2 =P2.X;
32 ny2 =P2.Y;
33 //检查数值合法性
34 if(nx<0)nx = 0;
35 if(ny<0)ny = 0;
36 if(nx2>xscrn)nx2 = xscrn;
37 if(ny2>yscrn)ny2 = yscrn;
38 }
39 nwidth = nx2 - nx;//截取范围的宽度
40 nheight = ny2 - ny;//截取范围的高度
41 hbitmap = CreateCompatibleBitmap(hscrdc, nwidth, nheight);//从内存DC复制到hbitmap句柄
42 holdbitmap = SelectObject(hmemdc, hbitmap);
43 BitBlt(hmemdc, 0, 0, nwidth, nheight,hscrdc, nx, ny,(UInt32)0xcc0020);
44 hbitmap = SelectObject(hmemdc, holdbitmap);
45 DeleteDC(hscrdc);//删除用过的对象
46 DeleteDC(hmemdc);//删除用过的对象
47 return Bitmap.FromHbitmap(hbitmap);//用Bitmap.FromHbitmap从hbitmap返回Bitmap
48 }
49
50
51
52 所用到的API声明:
53 [DllImport("gdi32.dll")]
54 public static extern IntPtr CreateDC(
55 string lpszDriver, // driver name
56 string lpszDevice, // device name
57 string lpszOutput, // not used; should be NULL
58 Int64 lpInitData // optional printer data
59 );
60 [DllImport("gdi32.dll")]
61 public static extern IntPtr CreateCompatibleDC(
62 IntPtr hdc // handle to DC
63 );
64 [DllImport("gdi32.dll")]
65 public static extern int GetDeviceCaps(
66 IntPtr hdc, // handle to DC
67 GetDeviceCapsIndex nIndex // index of capability
68 );
69 [DllImport("gdi32.dll")]
70 public static extern IntPtr CreateCompatibleBitmap(
71 IntPtr hdc, // handle to DC
72 int nWidth, // width of bitmap, in pixels
73 int nHeight // height of bitmap, in pixels
74 );
75 [DllImport("gdi32.dll")]
76 public static extern IntPtr SelectObject(
77 IntPtr hdc, // handle to DC
78 IntPtr hgdiobj // handle to object
79 );
80 [DllImport("gdi32.dll")]
81 public static extern int BitBlt(
82 IntPtr hdcDest, // handle to destination DC
83 int nXDest, // x-coord of destination upper-left corner
84 int nYDest, // y-coord of destination upper-left corner
85 int nWidth, // width of destination rectangle
86 int nHeight, // height of destination rectangle
87 IntPtr hdcSrc, // handle to source DC
88 int nXSrc, // x-coordinate of source upper-left corner
89 int nYSrc, // y-coordinate of source upper-left corner
90 UInt32 dwRop // raster operation code
91 );
92 [DllImport("gdi32.dll")]
93 public static extern int DeleteDC(
94 IntPtr hdc // handle to DC
95 );
1 /**////
2 /// 截取部分屏幕
3 ///
4 /// 左上角
5 /// 右下角
6 /// 是否全屏幕
7 /// 返回值Bitmap
8 public static Bitmap GetPartScreen(Point P1,Point P2,bool Full)
9 {
10 IntPtr hscrdc,hmemdc;
11 IntPtr hbitmap,holdbitmap;
12 int nx,ny,nx2,ny2;
13 nx=ny=nx2=ny2=0;
14 int nwidth, nheight;
15 int xscrn, yscrn;
16 hscrdc = CreateDC("DISPLAY", null, null, 0);//创建DC句柄
17 hmemdc = CreateCompatibleDC(hscrdc);//创建一个内存DC
18 xscrn = GetDeviceCaps(hscrdc, GetDeviceCapsIndex.HORZRES);//获取屏幕宽度
19 yscrn = GetDeviceCaps(hscrdc, GetDeviceCapsIndex.VERTRES);//获取屏幕高度
20 if(Full)//如果是截取整个屏幕
21 {
22 nx = 0;
23 ny = 0;
24 nx2 = xscrn;
25 ny2 = yscrn;
26 }
27 else
28 {
29 nx = P1.X;
30 ny = P1.Y;
31 nx2 =P2.X;
32 ny2 =P2.Y;
33 //检查数值合法性
34 if(nx<0)nx = 0;
35 if(ny<0)ny = 0;
36 if(nx2>xscrn)nx2 = xscrn;
37 if(ny2>yscrn)ny2 = yscrn;
38 }
39 nwidth = nx2 - nx;//截取范围的宽度
40 nheight = ny2 - ny;//截取范围的高度
41 hbitmap = CreateCompatibleBitmap(hscrdc, nwidth, nheight);//从内存DC复制到hbitmap句柄
42 holdbitmap = SelectObject(hmemdc, hbitmap);
43 BitBlt(hmemdc, 0, 0, nwidth, nheight,hscrdc, nx, ny,(UInt32)0xcc0020);
44 hbitmap = SelectObject(hmemdc, holdbitmap);
45 DeleteDC(hscrdc);//删除用过的对象
46 DeleteDC(hmemdc);//删除用过的对象
47 return Bitmap.FromHbitmap(hbitmap);//用Bitmap.FromHbitmap从hbitmap返回Bitmap
48 }
49
50
51
52 所用到的API声明:
53 [DllImport("gdi32.dll")]
54 public static extern IntPtr CreateDC(
55 string lpszDriver, // driver name
56 string lpszDevice, // device name
57 string lpszOutput, // not used; should be NULL
58 Int64 lpInitData // optional printer data
59 );
60 [DllImport("gdi32.dll")]
61 public static extern IntPtr CreateCompatibleDC(
62 IntPtr hdc // handle to DC
63 );
64 [DllImport("gdi32.dll")]
65 public static extern int GetDeviceCaps(
66 IntPtr hdc, // handle to DC
67 GetDeviceCapsIndex nIndex // index of capability
68 );
69 [DllImport("gdi32.dll")]
70 public static extern IntPtr CreateCompatibleBitmap(
71 IntPtr hdc, // handle to DC
72 int nWidth, // width of bitmap, in pixels
73 int nHeight // height of bitmap, in pixels
74 );
75 [DllImport("gdi32.dll")]
76 public static extern IntPtr SelectObject(
77 IntPtr hdc, // handle to DC
78 IntPtr hgdiobj // handle to object
79 );
80 [DllImport("gdi32.dll")]
81 public static extern int BitBlt(
82 IntPtr hdcDest, // handle to destination DC
83 int nXDest, // x-coord of destination upper-left corner
84 int nYDest, // y-coord of destination upper-left corner
85 int nWidth, // width of destination rectangle
86 int nHeight, // height of destination rectangle
87 IntPtr hdcSrc, // handle to source DC
88 int nXSrc, // x-coordinate of source upper-left corner
89 int nYSrc, // y-coordinate of source upper-left corner
90 UInt32 dwRop // raster operation code
91 );
92 [DllImport("gdi32.dll")]
93 public static extern int DeleteDC(
94 IntPtr hdc // handle to DC
95 );