c#调用摄像头

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

public class VideoWork
{
private const int WM_USER = 0×400;
private const int WS_CHILD = 0×40000000;
private const int WS_VISIBLE = 0×10000000;
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);

//
//这里特别注意，因为WinAPI中的long为32位，而C#中的long为64wei，所以需要将lParam该为int
//
[DllImport("User32.dll ")]
private static extern bool SendMessage(IntPtr hWnd, int wMsg, int wParam, int 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.ToInt32());
}
}

调用方法：

在窗体上拖入一个panel

调用代码为：

VideoWork wv = new VideoWork(panel1.Handle, 0, 0, panel1.Width, panel1.Height);
wv.Start();