C#摄像头实现拍照功能的简单代码示例
·摘要：这里将介绍一个C#摄像头实现拍照功能的简单代码示例，代码虽然不短，但是基本上实现了相对应的功能，希望对大家有所帮助。
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C#摄像头实现拍照功能的简单代码示例
1.using System;
2.using System.Runtime.InteropServices;
3.using System.Drawing;
4.using System.Drawing.Imaging;
5.namespace Video
6.{
7.///
8./// 一个C#摄像头控制类
9.///
10.publicclass VideoWork
11.{
12.privateconstint WM_USER = 0x400;
13.privateconstint WS_CHILD = 0x40000000;
14.privateconstint WS_VISIBLE = 0x10000000;
15.privateconstint WM_CAP_START = WM_USER;
16.privateconstint WM_CAP_STOP = WM_CAP_START + 68;
17.privateconstint WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10;
18.privateconstint WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11;
19.privateconstint WM_CAP_SAVEDIB = WM_CAP_START + 25;
20.privateconstint WM_CAP_GRAB_FRAME = WM_CAP_START + 60;
21.privateconstint WM_CAP_SEQUENCE = WM_CAP_START + 62;
22.privateconstint WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20;
23.privateconstint WM_CAP_SEQUENCE_NOFILE =WM_CAP_START+ 63;
24.privateconstint WM_CAP_SET_OVERLAY =WM_CAP_START+ 51;
25.privateconstint WM_CAP_SET_PREVIEW =WM_CAP_START+ 50;
26.privateconstint WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START +6;
27.privateconstint WM_CAP_SET_CALLBACK_ERROR=WM_CAP_START +2;
28.privateconstint WM_CAP_SET_CALLBACK_STATUSA= WM_CAP_START +3;
29.privateconstint WM_CAP_SET_CALLBACK_FRAME= WM_CAP_START +5;
30.privateconstint WM_CAP_SET_SCALE=WM_CAP_START+ 53;
31.privateconstint WM_CAP_SET_PREVIEWRATE=WM_CAP_START+ 52;
32.private IntPtr hWndC;
33.privatebool bWorkStart = false;
34.private IntPtr mControlPtr;
35.privateint mWidth;
36.privateint mHeight;
37.privateint mLeft;
38.privateint mTop;
39.
40.///
41./// 初始化显示图像
42.///
43./// 控件的句柄
44./// 开始显示的左边距
45./// 开始显示的上边距
46./// 要显示的宽度
47./// 要显示的长度
48.public VideoWork(IntPtr handle, int left, int top, int width,int height)
49.{
50.mControlPtr = handle;
51.mWidth = width;
52.mHeight = height;
53.mLeft = left;
54.mTop = top;
55.}
56.[DllImport("avicap32.dll")]
57.privatestaticextern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID);
58.[DllImport("avicap32.dll")]
59.privatestaticexternint capGetVideoFormat(IntPtr hWnd, IntPtr psVideoFormat, int wSize );
60.[DllImport("User32.dll")]
61.privatestaticexternbool SendMessage(IntPtr hWnd, int wMsg, int wParam, long lParam);
62.///
63./// 开始显示图像
64.///
65.publicvoid Start()
66.{
67.if (bWorkStart)
68.return;
69.bWorkStart = true;
70.byte[] lpszName = newbyte[100];
71.hWndC = capCreateCaptureWindowA(lpszName,WS_CHILD|WS_VISIBLE ,mLeft,mTop,mWidth,mHeight,mControlPtr,0);
72.if (hWndC.ToInt32() != 0)
73.{
74.SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);
75.SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);
76.SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);
77.SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);
78.SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);
79.SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);
80.SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);
81.SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);
82.//Global.log.Write("SendMessage");
83.}
84.return;
85.}
86.///
87./// 停止显示
88.///
89.publicvoid Stop()
90.{
91.SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
92.bWorkStart = false;
93.}
94.///
95./// 抓图
96.///
97./// 要保存bmp文件的路径
98.publicvoid GrabImage(string path)
99.{
100.IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);
101.SendMessage(hWndC,WM_CAP_SAVEDIB,0,hBmp.ToInt64());
102.}
103.}
104.}
105.
106.//这是一个控制摄像头进行拍照的类，我每次使用GrabImage抓图都是225K的一张照片，我想请问如何才能让我
107.//抓到的图片小一些，我想控制在70K左右。不知怎么让拍照的像素变小？
108.
109.if(this.Request.QueryString["filename"]!=null)
110.{
111.//获取原图片
112.string filename=this.Request.QueryString["filename"];
113.Bitmap bmpOld=new Bitmap(this.Server.MapPath("p_w_picpaths/" + filename));
114.//计算缩小比例
115.double d1;
116.if(bmpOld.Height>bmpOld.Width)
117.d1=(double)(MaxLength/(double)bmpOld.Width);
118.else
119.d1=(double)(MaxLength/(double)bmpOld.Height);
120.//产生缩图
121.Bitmap bmpThumb=new Bitmap(bmpOld,(int)(bmpOld.Width*d1),(int)(bmpOld.Height*d1));
122.//清除缓冲
123.Response.Clear();
124.//生成图片
125.bmpThumb.Save(this.Response.OutputStream,ImageFormat.Jpeg);
126.Response.End();
127.//释放资源
128.bmpThumb.Dispose();
129.bmpOld.Dispose();
130.}
C#摄像头实现拍照功能的简单代码示例就介绍到这里。
