装了摄像头后一般会有 avicap32.dll文件，没有一样可以用这些代码。
不需要在解决方案里面引用这个.dll文件。
下面有二种写法的例子：
例一：
using System;using System.Runtime.InteropServices;using System.Drawing;using System.Drawing.Imaging;namespace WinVideo
{
/// <summary>
/// webcam 的摘要说明。
/// </summary> public class webcam { private const int WM_USER=0x400; private const int WS_CHILD=0x40000000; private const int WS_VISIBLE=0x10000000; private const int WM_CAP_START=WM_USER; private const int WM_CAP_STOP=WM_CAP_START + 68; private const int WM_CAP_DRIVER_CONNECT=WM_CAP_START + 10; private const int WM_CAP_DRIVER_DISCONNECT=WM_CAP_START + 11; private const int WM_CAP_SAVEDIB=WM_CAP_START + 25; private const int WM_CAP_GRAB_FRAME=WM_CAP_START + 60; private const int WM_CAP_SEQUENCE=WM_CAP_START + 62; private const int WM_CAP_FILE_SET_CAPTURE_FILEA=WM_CAP_START + 20; private const int WM_CAP_SEQUENCE_NOFILE=WM_CAP_START+ 63; private const int WM_CAP_SET_OVERLAY=WM_CAP_START+ 51; private const int WM_CAP_SET_PREVIEW=WM_CAP_START+ 50; private const int WM_CAP_SET_CALLBACK_VIDEOSTREAM=WM_CAP_START +6; private const int WM_CAP_SET_CALLBACK_ERROR=WM_CAP_START +2; private const int WM_CAP_SET_CALLBACK_STATUSA=WM_CAP_START +3; private const int WM_CAP_SET_CALLBACK_FRAME=WM_CAP_START +5; private const int WM_CAP_SET_SCALE=WM_CAP_START+ 53; private const int WM_CAP_SET_PREVIEWRATE=WM_CAP_START+ 52; private IntPtr hWndC; private bool bStat = false; private IntPtr mControlPtr; private int mWidth; private int mHeight; private int mLeft; private int mTop; private string GrabImagePath=""; private string KinescopePath=""; /// <summary> /// 初始化摄像头 /// </summary> /// <param name="handle">控件的句柄</param> /// <param name="left">开始显示的左边距</param> /// <param name="top">开始显示的上边距</param> /// <param name="width">要显示的宽度</param> /// <param name="height">要显示的长度</param> public webcam(IntPtr handle,int left,int top,int width,int height) { mControlPtr=handle; mWidth=width; mHeight=height; mLeft=left; mTop=top; }
"属性设置" [DllImport("avicap32.dll")] private static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName,int dwStyle,int x,int y,int nWidth,int nHeight,IntPtr hWndParent,int nID); [DllImport("avicap32.dll")] private static extern int capGetVideoFormat(IntPtr hWnd,IntPtr psVideoFormat,int wSize ); [DllImport("User32.dll")] private static extern bool SendMessage(IntPtr hWnd,int wMsg,int wParam,long lParam); /// <summary> /// 开始显示图像 /// </summary> public void Start() { if(bStat) return; bStat=true; byte[] lpszName=new byte[100]; hWndC=capCreateCaptureWindowA(lpszName,WS_CHILD|WS_VISIBLE ,mLeft,mTop,mWidth,mHeight,mControlPtr,0); if (hWndC.ToInt32()!=0) { SendMessage(hWndC,WM_CAP_SET_CALLBACK_VIDEOSTREAM,0,0); SendMessage(hWndC,WM_CAP_SET_CALLBACK_ERROR,0,0); SendMessage(hWndC,WM_CAP_SET_CALLBACK_STATUSA,0,0); SendMessage(hWndC,WM_CAP_DRIVER_CONNECT,0,0); SendMessage(hWndC,WM_CAP_SET_SCALE,1,0); SendMessage(hWndC,WM_CAP_SET_PREVIEWRATE,66,0); SendMessage(hWndC,WM_CAP_SET_OVERLAY,1,0); SendMessage(hWndC,WM_CAP_SET_PREVIEW,1,0); } return; } /// <summary> /// 停止显示 /// </summary> public void Stop() { SendMessage(hWndC,WM_CAP_DRIVER_DISCONNECT,0,0); bStat=false; } /// <summary> /// 抓图 /// </summary> /// <param name="path">要保存bmp文件的路径</param> public void GrabImage() { IntPtr hBmp=Marshal.StringToHGlobalAnsi(GrabImagePath); SendMessage(hWndC,WM_CAP_SAVEDIB,0,hBmp.ToInt64()); } /// <summary> /// 录像 /// </summary> /// <param name="path">要保存avi文件的路径</param> public void Kinescope() { IntPtr hBmp=Marshal.StringToHGlobalAnsi(KinescopePath); SendMessage(hWndC,WM_CAP_FILE_SET_CAPTURE_FILEA,0,hBmp.ToInt64()); SendMessage(hWndC,WM_CAP_SEQUENCE,0,0); } /// <summary> /// 停止录像 /// </summary> public void StopKinescope() { SendMessage(hWndC,WM_CAP_STOP,0,0); } }
}对该类的调用：
public webcam wcam=null; private void Form1_Load(object sender, System.EventArgs e) { start(); this.btnKinescopeStop.Enabled=false; } private void btnStar_Click(object sender, System.EventArgs e) { wcam.Start(); } private void btnStop_Click(object sender, System.EventArgs e) { wcam.Stop(); } private void btnSnapPic_Click(object sender, System.EventArgs e) { //得到路径。例：d:/a.bmp string myPath=this.txtPath.Text; if(myPath=="") { MessageBox.Show("必须填写路径！"); return; } else { wcam.grabImagePath=myPath; wcam.GrabImage(); MessageBox.Show("截图成功！"); } } public void start() { //以panel1为容器显示视频内容 wcam=new webcam(panel1.Handle,0,0,this.panel1.Width,this.panel1.Height); wcam.Start(); } private void panel1_SizeChanged(object sender, System.EventArgs e) { wcam.Stop(); wcam.Height=this.panel1.Height; wcam.Width=this.panel1.Width; wcam.Start(); } private delegate void delegateKinescope(); private void btnKinescopeBegin_Click(object sender, System.EventArgs e) { //得到路径。例：d:/a.avi string myPath=this.txtPath.Text; if(myPath=="") { MessageBox.Show("必须填写路径！"); return; } else { wcam.kinescopePath=myPath; delegateKinescope myK=new delegateKinescope(wcam.Kinescope); Thread threadKinescope=new Thread(new ThreadStart(myK)); threadKinescope.Start(); this.btnKinescopeBegin.Enabled=false; this.btnKinescopeStop.Enabled=true; } } public void starKinescope() { delegateKinescope myK=new delegateKinescope(wcam.Kinescope); } private void btnKinescopeStop_Click(object sender, System.EventArgs e) { wcam.StopKinescope(); this.btnKinescopeBegin.Enabled=true; this.btnKinescopeStop.Enabled=false; }例二：
using System;using System.Runtime.InteropServices;namespace webcam{ /**//// /// avicap 的摘要说明。 /// public class showVideo { // showVideo calls [DllImport("avicap32.dll")] public static extern IntPtr capCreateCaptureWindowA(byte[] lpszWindowName, int dwStyle, int x, int y, int nWidth, int nHeight, IntPtr hWndParent, int nID); [DllImport("avicap32.dll")] public static extern bool capGetDriverDescriptionA(short wDriver, byte[] lpszName, int cbName, byte[] lpszVer, int cbVer); [DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, bool wParam, int lParam); [DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, int lParam); [DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, short wParam, FrameEventHandler lParam); [DllImport("User32.dll")] public static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, ref BITMAPINFO lParam); [DllImport("User32.dll")] public static extern int SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int y, int cx, int cy, int wFlags); [DllImport("avicap32.dll")]public static extern int capGetVideoFormat(IntPtr hWnd, IntPtr psVideoFormat, int wSize ); // Constants public const int WM_USER = 0x400; public const int WS_CHILD = 0x40000000; public const int WS_VISIBLE = 0x10000000; public const int SWP_NOMOVE = 0x2; public const int SWP_NOZORDER = 0x4; public const int WM_CAP_DRIVER_CONNECT = WM_USER + 10; public const int WM_CAP_DRIVER_DISCONNECT = WM_USER + 11; public const int WM_CAP_SET_CALLBACK_FRAME = WM_USER + 5; public const int WM_CAP_SET_PREVIEW = WM_USER + 50; public const int WM_CAP_SET_PREVIEWRATE = WM_USER + 52; public const int WM_CAP_SET_VIDEOFORMAT = WM_USER + 45; // Structures [StructLayout(LayoutKind.Sequential)] public struct VIDEOHDR { [MarshalAs(UnmanagedType.I4)] public int lpData; [MarshalAs(UnmanagedType.I4)] public int dwBufferLength; [MarshalAs(UnmanagedType.I4)] public int dwBytesUsed; [MarshalAs(UnmanagedType.I4)] public int dwTimeCaptured; [MarshalAs(UnmanagedType.I4)] public int dwUser; [MarshalAs(UnmanagedType.I4)] public int dwFlags; [MarshalAs(UnmanagedType.ByValArray, SizeConst=4)] public int[] dwReserved; } [StructLayout(LayoutKind.Sequential)] public struct BITMAPINFOHEADER { [MarshalAs(UnmanagedType.I4)] public Int32 biSize ; [MarshalAs(UnmanagedType.I4)] public Int32 biWidth ; [MarshalAs(UnmanagedType.I4)] public Int32 biHeight ; [MarshalAs(UnmanagedType.I2)] public short biPlanes; [MarshalAs(UnmanagedType.I2)] public short biBitCount ; [MarshalAs(UnmanagedType.I4)] public Int32 biCompression; [MarshalAs(UnmanagedType.I4)] public Int32 biSizeImage; [MarshalAs(UnmanagedType.I4)] public Int32 biXPelsPerMeter; [MarshalAs(UnmanagedType.I4)] public Int32 biYPelsPerMeter; [MarshalAs(UnmanagedType.I4)] public Int32 biClrUsed; [MarshalAs(UnmanagedType.I4)] public Int32 biClrImportant; } [StructLayout(LayoutKind.Sequential)] public struct BITMAPINFO { [MarshalAs(UnmanagedType.Struct, SizeConst=40)] public BITMAPINFOHEADER bmiHeader; [MarshalAs(UnmanagedType.ByValArray, SizeConst=1024)] public Int32[] bmiColors; } public delegate void FrameEventHandler(IntPtr lwnd, IntPtr lpVHdr); // Public methods public static object GetStructure(IntPtr ptr,ValueType structure) { return Marshal.PtrToStructure(ptr,structure.GetType()); } public static object GetStructure(int ptr,ValueType structure) { return GetStructure(new IntPtr(ptr),structure); } public static void Copy(IntPtr ptr,byte[] data) { Marshal.Copy(ptr,data,0,data.Length); } public static void Copy(int ptr,byte[] data) { Copy(new IntPtr(ptr),data); } public static int SizeOf(object structure) { return Marshal.SizeOf(structure); } } //Web Camera Class public class WebCamera { // Constructur public WebCamera(IntPtr handle, int width,int height) { mControlPtr = handle; mWidth = width; mHeight = height; } // delegate for frame callback public delegate void RecievedFrameEventHandler(byte[] data); public event RecievedFrameEventHandler RecievedFrame; private IntPtr lwndC; // Holds the unmanaged handle of the control private IntPtr mControlPtr; // Holds the managed pointer of the control private int mWidth; private int mHeight; private showVideo.FrameEventHandler mFrameEventHandler; // Delegate instance for the frame callback - must keep alive! gc should NOT collect it // Close the web camera public void CloseWebcam() { this.capDriverDisconnect(this.lwndC); } // start the web camera public void StartWebCam() { byte[] lpszName = new byte[100]; byte[] lpszVer = new byte[100]; showVideo.capGetDriverDescriptionA(0, lpszName, 100,lpszVer, 100); this.lwndC = showVideo.capCreateCaptureWindowA(lpszName, showVideo.WS_VISIBLE + showVideo.WS_CHILD, 0, 0, mWidth, mHeight, mControlPtr, 0); if (this.capDriverConnect(this.lwndC, 0)) { this.capPreviewRate(this.lwndC, 66); this.capPreview(this.lwndC, true); showVideo.BITMAPINFO bitmapinfo = new showVideo.BITMAPINFO(); bitmapinfo.bmiHeader.biSize = showVideo.SizeOf(bitmapinfo.bmiHeader); bitmapinfo.bmiHeader.biWidth = 352; bitmapinfo.bmiHeader.biHeight = 288; bitmapinfo.bmiHeader.biPlanes = 1; bitmapinfo.bmiHeader.biBitCount = 24; this.capSetVideoFormat(this.lwndC, ref bitmapinfo, showVideo.SizeOf(bitmapinfo)); this.mFrameEventHandler = new showVideo.FrameEventHandler(FrameCallBack); this.capSetCallbackOnFrame(this.lwndC, this.mFrameEventHandler); showVideo.SetWindowPos(this.lwndC, 0, 0, 0, mWidth , mHeight , 6); } } // private functions private bool capDriverConnect(IntPtr lwnd, short i) { return showVideo.SendMessage(lwnd, showVideo.WM_CAP_DRIVER_CONNECT, i, 0); } private bool capDriverDisconnect(IntPtr lwnd) { return showVideo.SendMessage(lwnd, showVideo.WM_CAP_DRIVER_DISCONNECT, 0, 0); } private bool capPreview(IntPtr lwnd, bool f) {return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_PREVIEW , f, 0);} private bool capPreviewRate(IntPtr lwnd, short wMS) { return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_PREVIEWRATE, wMS, 0); } private bool capSetCallbackOnFrame(IntPtr lwnd, showVideo.FrameEventHandler lpProc) { return showVideo.SendMessage(lwnd, showVideo.WM_CAP_SET_CALLBACK_FRAME, 0, lpProc); } private bool capSetVideoFormat(IntPtr hCapWnd, ref showVideo.BITMAPINFO BmpFormat, int CapFormatSize) { return showVideo.SendMessage(hCapWnd, showVideo.WM_CAP_SET_VIDEOFORMAT, CapFormatSize, ref BmpFormat); } private void FrameCallBack(IntPtr lwnd, IntPtr lpVHdr) { showVideo.VIDEOHDR videoHeader = new showVideo.VIDEOHDR(); byte[] VideoData; videoHeader = (showVideo.VIDEOHDR)showVideo.GetStructure(lpVHdr,videoHeader); VideoData = new byte[videoHeader.dwBytesUsed]; showVideo.Copy(videoHeader.lpData ,VideoData); if (this.RecievedFrame != null) this.RecievedFrame (VideoData); } }}调用代码：
WebCamera wc; private void Form1_Load(object sender, System.EventArgs e) { b_play.Enabled = false; b_stop.Enabled = true; panelPreview.Size = new Size(330,330); wc = new WebCamera( panelPreview.Handle,panelPreview.Width,panelPreview.Height); wc.StartWebCam(); } private void button1_Click(object sender, System.EventArgs e) { b_play.Enabled = false; b_stop.Enabled = true; panelPreview.Size = new Size(330,330); wc = new WebCamera( panelPreview.Handle,panelPreview.Width,panelPreview.Height); wc.StartWebCam(); } private void b_stop_Click(object sender, System.EventArgs e) { b_play.Enabled = true; b_stop.Enabled = false; wc.CloseWebcam(); }