WPF使用ZXing.Net生成二维码遇泛型参数错误的修复咨询

问题场景 #

按照旧教程在WPF应用中集成ZXing.Net实现二维码生成功能，安装最新版ZXing.Net后，复制教程中的代码到MainWindow.xaml.cs，出现编译错误：使用泛型类型‘BarcodeReader’需要1个类型参数。

相关代码片段：

private void BtnConvert_Click(object sender, RoutedEventArgs e)
{
    try
    {
        System.Drawing.Image img = null;
        BitmapImage bimg = new BitmapImage();
        using (var ms = new MemoryStream())
        {
            BarcodeWriter writer; // 错误相关行
            writer = new ZXing.BarcodeWriter() { Format = BarcodeFormat.QR_CODE }; // 错误相关行
            writer.Options.Height = 80;
            writer.Options.Width = 280;
            writer.Options.PureBarcode = true;
            img = writer.Write(this.txtbarcodecontent.Text);
            img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            ms.Position = 0;
            bimg.BeginInit();
            bimg.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
            bimg.CacheOption = BitmapCacheOption.OnLoad;
            bimg.UriSource = null;
            bimg.StreamSource = ms;
            bimg.EndInit();
            this.imgbarcode.Source = bimg;  
            this.tbkbarcodecontent.Text = this.txtbarcodecontent.Text;
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

引用的命名空间：

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using System.IO;
using ZXing;
using System.Drawing;

错误原因 #

旧教程使用的是ZXing.Net的旧版本，当时BarcodeWriter是非泛型类；而新版ZXing.Net中BarcodeWriter已改为泛型类BarcodeWriter<TOutput>，必须指定输出类型参数，因此直接实例化BarcodeWriter会触发编译错误。

修复方案 #

方案1：指定泛型类型参数（兼容原有System.Drawing.Image逻辑） #

将BarcodeWriter改为BarcodeWriter<System.Drawing.Image>，明确指定输出类型为System.Drawing.Image，修改后的代码如下：

private void BtnConvert_Click(object sender, RoutedEventArgs e)
{
    try
    {
        System.Drawing.Image img = null;
        BitmapImage bimg = new BitmapImage();
        using (var ms = new MemoryStream())
        {
            // 指定泛型参数为System.Drawing.Image
            BarcodeWriter<System.Drawing.Image> writer;
            writer = new ZXing.BarcodeWriter<System.Drawing.Image>() 
            { 
                Format = BarcodeFormat.QR_CODE,
                Options = new ZXing.Common.EncodingOptions
                {
                    Height = 80,
                    Width = 280,
                    PureBarcode = true
                }
            };
            img = writer.Write(this.txtbarcodecontent.Text);
            img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
            ms.Position = 0;
            bimg.BeginInit();
            bimg.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
            bimg.CacheOption = BitmapCacheOption.OnLoad;
            bimg.UriSource = null;
            bimg.StreamSource = ms;
            bimg.EndInit();
            this.imgbarcode.Source = bimg;  
            this.tbkbarcodecontent.Text = this.txtbarcodecontent.Text;
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

方案2：使用WPF适配的BarcodeWriterPixelData（推荐，避免System.Drawing依赖） #

ZXing.Net提供了针对WPF的BarcodeWriterPixelData，可以直接生成像素数据，无需依赖System.Drawing，更适合WPF环境。修改后的代码如下：

首先确保安装ZXing.Net.Bindings.Wpf NuGet包（如果未安装），然后修改代码：

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media.Imaging;
using System.IO;
using ZXing;
using ZXing.Common;

private void BtnConvert_Click(object sender, RoutedEventArgs e)
{
    try
    {
        BitmapImage bimg = new BitmapImage();
        var writer = new BarcodeWriterPixelData
        {
            Format = BarcodeFormat.QR_CODE,
            Options = new EncodingOptions
            {
                Height = 80,
                Width = 280,
                PureBarcode = true,
                Margin = 0
            }
        };
        var pixelData = writer.Write(this.txtbarcodecontent.Text);

        // 将PixelData转换为BitmapImage
        using (var ms = new MemoryStream())
        {
            var bitmap = new System.Drawing.Bitmap(pixelData.Width, pixelData.Height);
            var bitmapData = bitmap.LockBits(
                new System.Drawing.Rectangle(0, 0, pixelData.Width, pixelData.Height),
                System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
            System.Runtime.InteropServices.Marshal.Copy(pixelData.Pixels, 0, bitmapData.Scan0, pixelData.Pixels.Length);
            bitmap.UnlockBits(bitmapData);
            bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
            ms.Position = 0;

            bimg.BeginInit();
            bimg.CacheOption = BitmapCacheOption.OnLoad;
            bimg.StreamSource = ms;
            bimg.EndInit();
        }

        this.imgbarcode.Source = bimg;
        this.tbkbarcodecontent.Text = this.txtbarcodecontent.Text;
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

注意事项 #

• 如果使用方案2，需要安装ZXing.Net.Bindings.Wpf NuGet包，该包专门为WPF优化，减少不必要的依赖。
• 新版ZXing.Net中，EncodingOptions需要通过ZXing.Common命名空间引用，确保代码中添加using ZXing.Common;。

内容的提问来源于stack exchange，提问作者Jessica Sztefka