winform调用摄像头扫描识别条形码在文本框中，完整组件及代码

这里提供一个简单的WinForm组件和代码，可以调用摄像头扫描条形码并将其识别后显示在文本框中。使用了ZXing库进行条形码识别。

组件包含一个Button和一个TextBox控件，Button用于启动摄像头扫描，TextBox用于显示识别出的条形码内容。

首先需要安装ZXing库，可以通过NuGet包管理器安装。

代码如下：

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

namespace BarcodeScanner
{
    public partial class BarcodeScannerControl : UserControl
    {
        private readonly Webcam webcam;
        private readonly Timer timer;
        private readonly BarcodeReader barcodeReader;

        public BarcodeScannerControl()
        {
            InitializeComponent();

            webcam = new Webcam();
            timer = new Timer { Interval = 100 };
            barcodeReader = new BarcodeReader();
        }

        private void buttonScan_Click(object sender, EventArgs e)
        {
            if (webcam.IsRunning)
            {
                webcam.Stop();
                timer.Stop();
                buttonScan.Text = "Scan";
            }
            else
            {
                webcam.Start();
                timer.Start();
                buttonScan.Text = "Stop";
            }
        }

        private void timer_Tick(object sender, EventArgs e)
        {
            if (!webcam.IsRunning)
            {
                return;
            }

            using (var bitmap = webcam.GetBitmap())
            {
                if (bitmap == null)
                {
                    return;
                }

                var result = barcodeReader.Decode(bitmap);

                if (result == null)
                {
                    return;
                }

                textBoxBarcode.Text = result.Text;
                webcam.Stop();
                timer.Stop();
                buttonScan.Text = "Scan";
            }
        }
    }

    public class Webcam
    {
        private readonly VideoCaptureDevice videoCaptureDevice;

        public bool IsRunning { get; private set; }

        public Webcam()
        {
            var videoCaptureDeviceMoniker = (new FilterInfoCollection(FilterCategory.VideoInputDevice))[0].MonikerString;
            videoCaptureDevice = new VideoCaptureDevice(videoCaptureDeviceMoniker);
        }

        public void Start()
        {
            videoCaptureDevice.NewFrame += VideoCaptureDevice_NewFrame;
            videoCaptureDevice.Start();
            IsRunning = true;
        }

        public void Stop()
        {
            videoCaptureDevice.NewFrame -= VideoCaptureDevice_NewFrame;
            videoCaptureDevice.SignalToStop();
            videoCaptureDevice.WaitForStop();
            IsRunning = false;
        }

        public Bitmap GetBitmap()
        {
            return videoCaptureDevice.IsRunning ? (Bitmap)videoCaptureDevice.GetCurrentVideoFrame().Clone() : null;
        }

        private void VideoCaptureDevice_NewFrame(object sender, AForge.Video.NewFrameEventArgs eventArgs)
        {
            // Do nothing, just need to fire the event to obtain new frames
        }
    }
}

使用方法：

1. 新建一个WinForm应用程序，在设计视图中添加一个UserControl控件。

2. 在UserControl中添加一个Button和一个TextBox控件。

3. 将以上代码复制到UserControl的.cs文件中，并将命名空间改成你的应用程序命名空间。

4. 在UserControl中添加以下代码：

private readonly BarcodeScannerControl barcodeScannerControl;

public MainForm()
{
    InitializeComponent();

    barcodeScannerControl = new BarcodeScannerControl();
    Controls.Add(barcodeScannerControl);
    barcodeScannerControl.Dock = DockStyle.Fill;
}

5. 编译并运行程序，点击Button开始扫描条形码。扫描到条形码后，识别结果会显示在TextBox中。