安装摄像头后，一般可以找到一个avicap32.dll文件 

这是一个关于摄像头的类

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);

}

}

}

具体调用如下：

using   system;

using   System.Drawing;

using   System.Collections;

using   System.ComponentModel;

using   System.Windows.Forms;

using   System.Data;

using   webcam;

namespace   webcam

{

///  

///   Form1   的摘要说明。

///  

public   class   Form1   :   System.Windows.Forms.Form

{

private   System.Windows.Forms.Panel   panelPreview;

private   System.Windows.Forms.Button   b_play;

private   System.Windows.Forms.Button   b_stop;

///  

///   必需的设计器变量。

///  

private   System.ComponentModel.Container   components   =   null;

WebCamera   wc;

public   form1()

{

//

//   Windows   窗体设计器支持所必需的

//

InitializeComponent();

//

//   TODO:   在   InitializeComponent   调用后添加任何构造函数代码

//

}

///  

///   清理所有正在使用的资源。

///  

protected   override   void   Dispose(   bool   disposing   )

{

if(   disposing   )

{

if   (components   !=   null)  

{

components.Dispose();

}

}

base.Dispose(   disposing   );

}

#region   windows   窗体设计器生成的代码

///  

///   设计器支持所需的方法   -   不要使用代码编辑器修改

///   此方法的内容。

///  

private   void   InitializeComponent()

{

this.b_play   =   new   System.Windows.Forms.Button();

this.panelPreview   =   new   System.Windows.Forms.Panel();

this.b_stop   =   new   System.Windows.Forms.Button();

this.SuspendLayout();

//  

//   b_play

//  

this.b_play.Location   =   new   System.Drawing.Point(280,   368);

this.b_play.Name   =   "b_play";

this.b_play.TabIndex   =   0;

this.b_play.Text   =   "&Play";

this.b_play.Click   +=   new   System.EventHandler(this.button1_Click);

//  

//   panelPreview

//  

this.panelPreview.Location   =   new   System.Drawing.Point(8,   8);

this.panelPreview.Name   =   "panelPreview";

this.panelPreview.Size   =   new   System.Drawing.Size(344,   272);

this.panelPreview.TabIndex   =   1;

//  

//   b_stop

//  

this.b_stop.Enabled   =   false;

this.b_stop.Location   =   new   System.Drawing.Point(360,   368);

this.b_stop.Name   =   "b_stop";

this.b_stop.TabIndex   =   2;

this.b_stop.Text   =   "&Stop";

this.b_stop.Click   +=   new   System.EventHandler(this.b_stop_Click);

//  

//   Form1

//  

this.AutoScaleBaseSize   =   new   System.Drawing.Size(6,   14);

this.ClientSize   =   new   System.Drawing.Size(464,   413);

this.Controls.Add(this.b_stop);

this.Controls.Add(this.panelPreview);

this.Controls.Add(this.b_play);

this.MaximizeBox   =   false;

this.MinimizeBox   =   false;

this.Name   =   "Form1";

this.Text   =   "GoodView   test   Web   Camera";

this.Load   +=   new   System.EventHandler(this.Form1_Load);

this.ResumeLayout(false);

}

#endregion

///  

///   应用程序的主入口点。

///  

[STAThread]

static   void   Main()  

{

Application.Run(new   Form1());

}

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();

}

}

}