c#程序调用摄像头程序总是弹出视频源
RT，网上有人说是线程堵塞的问题。但是我没有开启与摄像头相关的进程呀。跪求大神帮忙！
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
namespace video
{
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);
//
//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());
}
/// <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.ToInt32());
SendMessage(hWndC, WM_CAP_SEQUENCE, 0, 0);
}
/// <summary>
/// 停止录像
/// </summary>
public void StopKinescope()
{
SendMessage(hWndC, WM_CAP_STOP, 0, 0);
}
}
}
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing.Imaging;
using System.Text;
using System.Windows;
using System.Windows.Forms;
using System.IO;
using AForge;
using AForge.Controls;
using AForge.Video;
using AForge.Video.DirectShow;
using Size = System.Drawing.Size;
using video;
namespace video
{
public partial class Form1 : Form
{
private FilterInfoCollection videoDevices;
private VideoCaptureDevice videoSource;
public Form1()
{
InitializeComponent();
}
VideoWork wv;
private void button1_Click(object sender, EventArgs e)
{
wv = new VideoWork(this.panel1.Handle, 0, 0, this.panel1.Width, panel1.Height);
wv.Start();
wv.Start();
}
private void button2_Click(object sender, EventArgs e)
{
string path=@"c:\1.bmp";
wv.GrabImage(path);
}
private void Form1_Load(object sender, EventArgs e)
{
try
{
// 枚举所有视频输入设备
videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
if (videoDevices.Count == 0)
throw new ApplicationException();
foreach (FilterInfo device in videoDevices)
{
tscbxCameras.Items.Add(device.Name);
}
tscbxCameras.SelectedIndex = 0;
}
catch (ApplicationException)
{
tscbxCameras.Items.Add("No local capture devices");
videoDevices = null;
}
}
private void button3_Click(object sender, EventArgs e)
{
if (button3.Text=="录像")
{
string path = @"c:\2.avi";
wv.Kinescope(path);
button3.Text = "停止";
}
else
{
wv.StopKinescope();
}
}
private void panel1_Paint(object sender, PaintEventArgs e)
{
}
}
}
我也遇到过这个问题，网上给出的比较靠谱的答案是 多次调用打开方法，确实，多打开，多选择几次，最后可以打开视频，但是这样用户完全受不不了！
这个问题的发生跟设备已经当时的运行环境有关联。
后来，我终于在开源工程codeproject找到了一个新的组件 webCameraControl，用这个组件整个世界顿时安静了，非常好用，兼容性特别好