1.添加引用

using System.Windows.Media.Imaging;
using AForge;
using AForge.Controls;
using AForge.Video;
using AForge.Video.DirectShow;
using Size = System.Drawing.Size;

//连接摄像头====================================
private void CameraConn()
{
VideoCaptureDevice videoSource = new VideoCaptureDevice(videoDevices[tscbxCameras.SelectedIndex].MonikerString);
videoSource.DesiredFrameSize = new System.Drawing.Size(320, 240);
videoSource.DesiredFrameRate = 1;

videoSourcePlayer.VideoSource = videoSource;
videoSourcePlayer.Start();
}　　

3.关闭摄像头=================================

private void btnClose_Click(object sender, EventArgs e)

{
       videoSourcePlayer.SignalToStop();
       videoSourcePlayer.WaitForStop();
}


4.截图============================

private void Photograph_Click(object sender, EventArgs e)
{
try
{
if (videoSourcePlayer.IsRunning)
{
BitmapSource bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
videoSourcePlayer.GetCurrentVideoFrame().GetHbitmap(),
IntPtr.Zero,
Int32Rect.Empty,
BitmapSizeOptions.FromEmptyOptions());
PngBitmapEncoder pE = new PngBitmapEncoder();
pE.Frames.Add(BitmapFrame.Create(bitmapSource));
string picName = GetImagePath() + "\\" + "xiaosy" + ".jpg";
if (File.Exists(picName))
{
File.Delete(picName);
}
using (Stream stream = File.Create(picName))
{
pE.Save(stream);
}
//拍照完成后关摄像头并刷新同时关窗体
if (videoSourcePlayer != null && videoSourcePlayer.IsRunning)
{
videoSourcePlayer.SignalToStop();
videoSourcePlayer.WaitForStop();
}

this.Close();
}
}
catch (Exception ex)
{
MessageBox.Show("摄像头异常：" + ex.Message);
}
}

private string GetImagePath()
{
string personImgPath = Path.GetDirectoryName(AppDomain.CurrentDomain.BaseDirectory)
+ Path.DirectorySeparatorChar.ToString() + "PersonImg";
if (!Directory.Exists(personImgPath))
{
Directory.CreateDirectory(personImgPath);
}

return personImgPath;
}