winform打开本地摄像头识别条形码在文本框中，完整代码及组件

以下是一个基于WinForm的条形码识别程序的完整代码及组件。

首先需要引入以下命名空间：

using System;
using System.Drawing;
using System.Windows.Forms;
using AForge.Video;
using AForge.Video.DirectShow;
using ZXing;

然后在Form的类中定义以下字段：

private FilterInfoCollection videoDevices;
private VideoCaptureDevice videoDevice;
private Bitmap currentFrame;
private BarcodeReader barcodeReader;

在Form的构造函数中初始化这些字段：

public Form1()
{
    InitializeComponent();

    // 初始化摄像头设备
    videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
    if (videoDevices.Count != 0)
    {
        videoDevice = new VideoCaptureDevice(videoDevices[0].MonikerString);
        videoDevice.NewFrame += new NewFrameEventHandler(videoDevice_NewFrame);
        videoDevice.Start();
    }

    // 初始化条形码读取器
    barcodeReader = new BarcodeReader();
}

在Form的FormClosing事件中停止摄像头设备：

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    if (videoDevice != null && videoDevice.IsRunning)
    {
        videoDevice.SignalToStop();
        videoDevice.WaitForStop();
        videoDevice = null;
    }
}

在Form中添加一个PictureBox控件，并在videoDevice_NewFrame事件中实时显示摄像头捕获的画面：

private void videoDevice_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
    // 显示摄像头捕获的画面
    currentFrame = (Bitmap)eventArgs.Frame.Clone();
    pictureBox1.Image = currentFrame;
}

最后，在Form中添加一个TextBox控件，并在Timer的Tick事件中实现条形码识别并将结果显示在TextBox中：

private void timer1_Tick(object sender, EventArgs e)
{
    // 识别条形码并显示结果
    if (currentFrame != null)
    {
        Result result = barcodeReader.Decode(currentFrame);
        if (result != null)
        {
            textBox1.Text = result.Text;
        }
    }
}

完整代码如下：

using System;
using System.Drawing;
using System.Windows.Forms;
using AForge.Video;
using AForge.Video.DirectShow;
using ZXing;

namespace BarcodeReader
{
    public partial class Form1 : Form
    {
        private FilterInfoCollection videoDevices;
        private VideoCaptureDevice videoDevice;
        private Bitmap currentFrame;
        private BarcodeReader barcodeReader;

        public Form1()
        {
            InitializeComponent();

            // 初始化摄像头设备
            videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
            if (videoDevices.Count != 0)
            {
                videoDevice = new VideoCaptureDevice(videoDevices[0].MonikerString);
                videoDevice.NewFrame += new NewFrameEventHandler(videoDevice_NewFrame);
                videoDevice.Start();
            }

            // 初始化条形码读取器
            barcodeReader = new BarcodeReader();
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (videoDevice != null && videoDevice.IsRunning)
            {
                videoDevice.SignalToStop();
                videoDevice.WaitForStop();
                videoDevice = null;
            }
        }

        private void videoDevice_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            // 显示摄像头捕获的画面
            currentFrame = (Bitmap)eventArgs.Frame.Clone();
            pictureBox1.Image = currentFrame;
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            // 识别条形码并显示结果
            if (currentFrame != null)
            {
                Result result = barcodeReader.Decode(currentFrame);
                if (result != null)
                {
                    textBox1.Text = result.Text;
                }
            }
        }
    }
}

需要注意的是，以上代码中使用了AForge和ZXing两个第三方库，需要通过NuGet安装。可以在Visual Studio中打开“工具”->“NuGet包管理器”->“管理解决方案的NuGet包”窗口，搜索并安装AForge和ZXing。