c# - 如何初始化AForge网络摄像头

Question

我尝试编写少量代码来使用 Aforge 捕获帧我引用了 Aforge.dll 和 AForge.Video.DirectShow.dll代码在下面，但我做错了什么。我得到的警告“名称 videoDevices 在当前上下文中不存在。我认为这与我尝试创建该变量的位置有关，但我不确定将按钮代码放置在何处以对其进行初始化。该错误在 visual studio 中也显示为对象“videoDevices”下的红线

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using AForge;
using AForge.Video.DirectShow;

namespace AforgeCam
 {
   public partial class Form1 : Form
 {
    public Form1()
    {
        InitializeComponent();

    }

    private void button1_Click(object sender, EventArgs e)
    {

        videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);

        if (videoDevices.Count == 0)
            throw new ApplicationException();

        foreach (FilterInfo device in videoDevices)
        {
    VideoCaptureDevice videoSource = new    VideoCaptureDevice(device.MonikerString);
            videoSource.DesiredFrameSize = new Size(320, 240);
            videoSource.DesiredFrameRate = 15;
            videoSourcePlayer1.VideoSource = videoSource;
            videoSourcePlayer1.Start();
        }

    }
    }
}

Answer 1

根据要求，解决方案如下，代码有效，我将针对另一个问题提出一个新问题。该代码需要一个下拉框、两个按钮和一个图片框

using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using AforgeCam;
using AForge.Video;
using AForge.Video.DirectShow;

namespace AforgeCam
{
public partial class Form1 : Form
{
private FilterInfoCollection VideoCaptureDevices;
private VideoCaptureDevice FinalVideo;

public Form1() // init
{
    InitializeComponent();
    {
        VideoCaptureDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
        foreach (FilterInfo VideoCaptureDevice in VideoCaptureDevices)
        {
            comboBox1.Items.Add(VideoCaptureDevice.Name);
        }
        comboBox1.SelectedIndex = 0;
    }
}

private void button1_Click(object sender, EventArgs e)
{
    FinalVideo = new VideoCaptureDevice(VideoCaptureDevices[comboBox1.SelectedIndex].MonikerString);
    FinalVideo.NewFrame += new NewFrameEventHandler(FinalVideo_NewFrame);
    FinalVideo.Start();
}

void FinalVideo_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
    Bitmap video = (Bitmap)eventArgs.Frame.Clone();
    pictureBox1.Image = video;

}

private void button2_Click(object sender, EventArgs e)
{
    FinalVideo.Stop();
}
}