c#实现摄像头拍照功能示例

using system.drawing;
using system.drawing.imaging;
using system;
using system.runtime.interopservices;

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 videoclass(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);

[dllimport("avicap32.dll")]
public static extern bool capgetdriverdescriptiona(short wdriver, byte[] lpszname, int cbname, byte[] lpszver, int cbver);

/// <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 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);
        }