c# 读取摄像头录像截图

    using System;　　using System.Runtime.InteropServices;　　using System.Drawing;　　using System.Drawing.Imaging;　　namespace using System;　　using System.Runtime.InteropServices;　　using System.Drawing;　　using System.Drawing.Imaging;　　namespace PickHead　　{　　/// <summary>　　/// 一个控制摄像头的类　　/// </summary>　　public class Pick　　{　　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;　　　　/// <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 Pick(IntPtr handle, int left, int top, int width,int height)　　{　　mControlPtr = handle;　　mWidth = width;　　mHeight = height;[page_break]mLeft = left;　　mTop = top;　　}　　[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[page_break]/// </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(string path)　　{　　　　IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);　　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(string path)　　{　　IntPtr hBmp = Marshal.StringToHGlobalAnsi(path);　　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);　　}　　}　　}