winfrom控制相机拍照

using System;
using System.Runtime.InteropServices;

// public delegate void SaveImg(Pick Pick1);
/// <summary>
/// 一个控制摄像头的类
/// </summary>
public class CameraManager
{
    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 CameraManager(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 (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 CatchImage(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);
    }

}