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  • c# 摄像头截图

    using System;
    using System.Runtime.InteropServices;
    using System.Drawing;
    using System.Drawing.Imaging;
    namespace Video
    {
    /// <summary>
    /// 一个控制摄像头的类
    /// </summary>
    public class VideoWork
    {
    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 bWorkStart = false;
    private IntPtr mControlPtr;
    private int mWidth;
    private int mHeight;
    private int mLeft;
    private int mTop;
    
    /// <summary>
    /// 初始化显示图像
    /// </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 VideoWork(IntPtr handle, int left, int top, int width,int height)
    {
    mControlPtr = handle;
    mWidth = width;
    mHeight = height;
    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 (bWorkStart)
    return;
    bWorkStart = 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);
    //Global.log.Write("SendMessage");
    }
    return;
    }
    /// <summary>
    /// 停止显示
    /// </summary>
    public void Stop()
    {
    SendMessage(hWndC, WM_CAP_DRIVER_DISCONNECT, 0, 0);
    bWorkStart = 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());
    }
    }
    }
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  • 原文地址:https://www.cnblogs.com/gwazy/p/2715686.html
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