1.登錄http://zxingnet.codeplex.com/，下載對應.net版本的zxing庫

2.引入zxing.dll

3.新建界面控件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using
 
 System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using ZXing.Common;
using ZXing;
using ZXing.QrCode;
using System.Runtime.InteropServices;
using System.Drawing;

namespace zxingQRCodeDemo
{
    /// <summary>
    /// MainWindow.xaml 的交互邏輯
    
 
/// </summary>
    public partial class MainWindow : Window
    {
        // 註銷對象方法API
        [DllImport("gdi32")]
        static extern int DeleteObject(IntPtr o);
        public MainWindow()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 創建二維碼圖像
        
 
/// </summary>
        /// <param name="content">要寫入的內容</param>
        /// <param name="width">寬</param>
        /// <param name="height">高</param>
        /// <returns></returns>
        private ImageSource createQRCode(String content, int width, int height)
        {
            EncodingOptions options;
            //包含一些編碼、大小等的設置
            //BarcodeWriter :一個智能類來編碼一些內容的條形碼圖像
            BarcodeWriter write = null;
            options = new QrCodeEncodingOptions
            {
                DisableECI = true,
                CharacterSet = "UTF-8",
                Width = width,
                Height = height,
                Margin = 0
            };
            write = new BarcodeWriter();
            //設置條形碼格式
            write.Format = BarcodeFormat.QR_CODE;
            //獲取或設置選項容器的編碼和渲染過程。
            write.Options = options;
            //對指定的內容進行編碼，並返回該條碼的呈現實例。渲染屬性渲染實例使用，必須設置方法調用之前。
            Bitmap bitmap = write.Write(content);
            IntPtr ip = bitmap.GetHbitmap();//從GDI+ Bitmap創建GDI位圖對象
                                            //Imaging.CreateBitmapSourceFromHBitmap方法，基於所提供的非托管位圖和調色板信息的指針，返回一個托管的BitmapSource
            BitmapSource bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, IntPtr.Zero, Int32Rect.Empty,
            System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
            DeleteObject(ip);
            return bitmapSource;
        }

        private void btnMake_Click(object sender, RoutedEventArgs e)
        {
            imQRCode.Source = createQRCode("牛逼不牛逼", 250, 250);
        }
    }
}

WPF調用zxing生成二維碼