安裝攝像頭後，一般可以找到一個avicap32.dll文件
這是一個關於設想頭的類
using system;
using System.Runtime.InteropServices;
namespace webcam
{
///
/// avicap 的摘要說明。
///
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);
}
}
}
