前言：

有些业务场景没有复杂的工业图像处理应用，只是简易使用视频展示，或者GDI+简单二次开发，就没必要使用halcon、海康VM等，这时候可以采用简单的AForge开源库进行操作。

需求

枚举所有摄像头，并找出需要的那个摄像头进行图像展示，存图、也可以进行图像旋转

AForge库的功能

如何使用

在NuGet,安装AForge库

1. 枚举摄像头
2. 选择分辨率
3. 注册图像处理回调
4. 开始采图
5. UI(来自于网络)

6.代码部分，声明来自于网络，我增加了图像旋转部分

  public partial class FrmMain : Form
    {
        public FrmMain()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 摄像头集合
        /// </summary>
        private FilterInfoCollection videoDevices;
        /// <summary>
        /// 具体摄像头
        /// </summary>
        private VideoCaptureDevice videoDevice;
        /// <summary>
        /// 分辨率对象
        /// </summary>
        private VideoCapabilities[] videoCapabilities;

     
        private void FrmMain_Load(object sender, EventArgs e)
        {
            //获取内置、外接摄像头，非网络摄像头
            videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
            if (videoDevices.Count != 0)
            {
                foreach (FilterInfo device in videoDevices)
                {
                    cbo_camera.Items.Add(device.Name);
                }
            }
            else
            {
                cbo_camera.Items.Add("没有找到摄像头");
            }

            cbo_camera.SelectedIndex = 0;
        }

        private void cbo_camera_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (videoDevices.Count != 0)
            {
                //获取每个摄像头支持的分辨率
                videoDevice = new VideoCaptureDevice(videoDevices[cbo_camera.SelectedIndex].MonikerString);
                GetDeviceResolution(videoDevice);
            }
        }

        /// <summary>
        /// 获取每个摄像头支持的分辨率
        /// </summary>
        /// <param name="videoCaptureDevice"></param>
        private void GetDeviceResolution(VideoCaptureDevice videoCaptureDevice)
        {
            cbo_rate.Items.Clear();
            videoCapabilities = videoCaptureDevice.VideoCapabilities;
            foreach (VideoCapabilities capabilty in videoCapabilities)
            {
                cbo_rate.Items.Add(#34;{capabilty.FrameSize.Width} x {capabilty.FrameSize.Height}");
            }
            cbo_rate.SelectedIndex = 0;
        }

        private void btn_conn_Click(object sender, EventArgs e)
        {
            if (videoDevice != null)
            {
                if ((videoCapabilities != null) && (videoCapabilities.Length != 0))
                {
                    videoDevice.VideoResolution = videoCapabilities[cbo_rate.SelectedIndex];
                 
                    myvideo.VideoSource = videoDevice;
                    myvideo.NewFrame += Myvideo_NewFrame;//进行图像二次处理
                    myvideo.Start();
                    btn_conn.Enabled = false;
                    btn_stop.Enabled = true;
                    btn_cap.Enabled = true;
                }
            }
        }

        private void Myvideo_NewFrame(object sender, ref Bitmap image)
        {
            #region 方法一
            //image.RotateFlip(RotateFlipType.Rotate180FlipX);
            #endregion
            #region 方法二
            RotateBilinear rotate = new RotateBilinear((int)numRotate.Value); // 图像旋转值
            image = rotate.Apply(image);
            #endregion


        }

        private void btn_stop_Click(object sender, EventArgs e)
        {
            if (myvideo.VideoSource != null)
            {
                myvideo.SignalToStop();
                myvideo.WaitForStop();
                myvideo.VideoSource = null;

                btn_conn.Enabled = true;
                btn_stop.Enabled = false;
                btn_cap.Enabled = false;
            }
        }

        private void btn_cap_Click(object sender, EventArgs e)
        {
            if (myvideo.VideoSource != null)
            {
                Bitmap img = myvideo.GetCurrentVideoFrame();
                img.Save("001.jpg");
                MessageBox.Show("抓拍成功，文件在程序根目录下。");
            }
        }

        /// <summary>
        /// 窗体关闭程序退出时断开摄像头连接
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void FrmMain_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (myvideo.VideoSource != null)
            {
                myvideo.SignalToStop();
                myvideo.WaitForStop();
                myvideo.VideoSource = null;

                btn_conn.Enabled = true;
                btn_stop.Enabled = false;
                btn_cap.Enabled = false;
            }
        }
      /*
      栋哥自动化 V=  dgzdh1
      */
        private void btnRotate_Click(object sender, EventArgs e)
        {

        }
    }

效果如下动图