AForge 播放摄像头（一）

在WPF中 和 WinForm中使用有些细微差别需要注意

WinForm

using System;
using System.Drawing;
using System.Windows.Forms;

using AForge.Video;
using AForge.Video.DirectShow;

namespace WindowsFormsApplication_Video
{
    public partial class Form1 : Form
    {
        private FilterInfoCollection _videoDevices = null;
        private VideoCaptureDevice _cameraDevice = null;

        public Form1()
        {
            InitializeComponent();

            this.FormClosing += Form1_FormClosing;
            try
            {
                _videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
                if (_videoDevices.Count == 0)
                {
                    MessageBox.Show("未找到摄像头");
                    return;
                }
                FilterInfo info = _videoDevices[0];//获取第一个摄像头
                _cameraDevice = new VideoCaptureDevice(info.MonikerString);
                _cameraDevice.NewFrame += OnCameraNewFrame;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "错误");
            }
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            OnStopCamera();
        }

        private void OnStartCamera()
        {
            if (_cameraDevice != null)
                _cameraDevice.Start();
        }

        private void OnStopCamera()
        {
            //WinForm可以直接调用Stop,但是WPF不可以，会卡住
            if (_cameraDevice != null && _cameraDevice.IsRunning)
                _cameraDevice.Stop();

            //WPF方式
            //if (_cameraDevice != null && _cameraDevice.IsRunning)
            //_cameraDevice.SignalToStop();
        }

        //异步线程
        private void OnCameraNewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            Bitmap bmp = (Bitmap)eventArgs.Frame.Clone();
            pictureBox1.Image = bmp;
        }

        private void playToolStripMenuItem_Click(object sender, EventArgs e)
        {
            OnStartCamera();
        }

        private void pauseToolStripMenuItem_Click(object sender, EventArgs e)
        {
            OnStopCamera();
        }
    }
}