1.下载ThoughtWorks.QRCode引用并添加在工程中
2.在实现类QRCodeEncoderDemo中引入Dll，添加方法

using System;
 
using System.Collections.Generic;
 
using System.Drawing;
 
using System.Drawing.Drawing2D;
 
using System.Linq;
 
using System.Web;
 
using ThoughtWorks.QRCode;
 
 
using ThoughtWorks.QRCode.Codec;
 
namespace WebApplication3
 
{
 
    public class QRCodeEncoderDemo
 
    {
 
        /// <summary>  
 
        /// 生成二维码.  
 
        /// </summary>  
 
        /// <param name="data">需要添加进去的文本</param>  
 
        /// <returns></returns>  
 
        public System.Drawing.Image GCode(String data)
 
        {
 
            
 
           QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
 
             
 
            qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
 
            qrCodeEncoder.QRCodeScale = 5;
 
            qrCodeEncoder.QRCodeVersion = 7;
 
 
            qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.L;
 
            var pbImg = qrCodeEncoder.Encode(data, System.Text.Encoding.UTF8);
 
            var width = pbImg.Width / 10;
 
            var dwidth = width * 2;
 
            Bitmap bmp = new Bitmap(pbImg.Width + dwidth, pbImg.Height + dwidth);
 
            Graphics g = Graphics.FromImage(bmp);
 
            var c = System.Drawing.Color.White;
 
            g.FillRectangle(new SolidBrush(c), 0, 0, pbImg.Width + dwidth, pbImg.Height + dwidth);
 
            g.DrawImage(pbImg, width, width);
 
            g.Dispose();
 
            return bmp;
 
        }
 
 
        /// <summary>  
 
        /// 调用此函数后使此两种图片合并，类似相册，有个  
 
        /// 背景图，中间贴自己的目标图片  
 
        /// </summary>  
 
        /// <param name="sourceImg">粘贴的源图片</param>  
 
        /// <param name="destImg">粘贴的目标图片</param>  
 
        public static System.Drawing.Image CombinImage(System.Drawing.Image imgBack, string destImg)
 
        {
 
 
            System.Drawing.Image img = System.Drawing.Image.FromFile(destImg);        //照片图片    
 
            if (img.Height != 50 || img.Width != 50)
 
            {
 
                img = KiResizeImage(img, 60, 60, 0);
 
            }
 
            Graphics g = Graphics.FromImage(imgBack);
 
 
            //g.DrawImage(imgBack, 0, 0, 相框宽, 相框高); 
 
            g.DrawImage(imgBack, 0, 0, imgBack.Width, imgBack.Height);        
 
 
            //g.FillRectangle(System.Drawing.Brushes.White, imgBack.Width / 2 - img.Width / 2 - 1, imgBack.Width / 2 - img.Width / 2 - 1,1,1);
 
            //相片四周刷一层黑色边框  
 
 
            //g.DrawImage(img, 照片与相框的左边距, 照片与相框的上边距, 照片宽, 照片高);  
 
 
            g.DrawImage(img, imgBack.Width / 2 - img.Width / 2, imgBack.Width / 2 - img.Width / 2, img.Width, img.Height);
 
            GC.Collect();
 
            return imgBack;
 
        }
 
 
        /// <summary>  
 
        /// Resize图片  
 
        /// </summary>  
 
        /// <param name="bmp">原始Bitmap</param>  
 
        /// <param name="newW">新的宽度</param>  
 
        /// <param name="newH">新的高度</param>  
 
        /// <param name="Mode">保留着，暂时未用</param>  
 
        /// <returns>处理以后的图片</returns>  
 
        public static System.Drawing.Image KiResizeImage(System.Drawing.Image bmp, int newW, int newH, int Mode)
 
        {
 
            try
 
            {
 
                System.Drawing.Image b = new Bitmap(newW, newH);
 
                Graphics g = Graphics.FromImage(b);
 
 
                // 插值算法的质量  
 
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
 
 
                g.DrawImage(bmp, new Rectangle(0, 0, newW, newH), new Rectangle(0, 0, bmp.Width, bmp.Height), GraphicsUnit.Pixel);
 
                g.Dispose();
 
 
                return b;
 
            }
 
            catch
 
            {
 
                return null;
 
            }
 
        }
 
    }
 
}

 3.生成二维码(psb.jpg可自选，此处默认)

protected void BtnCreate_Click(object sender, EventArgs e)
 
{         
 
    QRCodeEncoderDemo qrc = new QRCodeEncoderDemo();
 
    //生成二维码图片
 
    System.Drawing.Image ImageBack=qrc.GCode(this.txtstr.Text.ToString());
 
    string DestImg = Server.MapPath(@"~/Image/psb.jpg");
 
    System.Drawing.Image Img = QRCodeEncoderDemo.CombinImage(ImageBack, DestImg);
 
    string filename = DateTime.Now.ToString("yyyyMMddhhmmss") + ".jpg";
 
    Img.Save(Server.MapPath(@"~/Image/") + filename);
 
    this.Img.ImageUrl = "~/Image/" + filename;
 
}

  4.解析二维码

protected void Button1_Click(object sender, EventArgs e)
 
        {
 
            QRCodeDecoder decoder = new QRCodeDecoder();
 
           Bitmap bt = new Bitmap(Server.MapPath(@"~/Image/"+this.Img.ImageUrl.Substring(this.Img.ImageUrl.LastIndexOf('/'))));
 
            string decodedString = decoder.decode(new QRCodeBitmapImage(bt),Encoding.UTF8);
 
            this.TxtContent.Text = decodedString;
 
        }