1.先下载NuGet包(ZXing.Net)

2.新建控制器及编写后台代码

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using ZXing;
using ZXing.QrCode;

namespace WebApplication1.Controllers
{
public class StrController : Controller
{
// GET: Str
public ActionResult Index()
{
return View();
}
///

/// 生成二维码方法 ///

/// 输入的字符串
/// 二维码宽度
/// 二维码高度
///
public string QRcode(string text, string width, string height)
{
string Response = "";
try
{
BarcodeWriter writer = new BarcodeWriter();
writer.Format = BarcodeFormat.QR_CODE;
QrCodeEncodingOptions options = new QrCodeEncodingOptions();
options.DisableECI = true;
//设置内容编码
options.CharacterSet = "UTF-8";
//将传来的值赋给二维码的宽度和高度
options.Width = Convert.ToInt32(width);
options.Height = Convert.ToInt32(height);
//设置二维码的边距,单位不是固定像素
options.Margin = ;
writer.Options = options;

            Bitmap map = writer.Write(text);  
            string di = text + DateTime.Now.ToString("yyyyMMddHHmmss") + ".png";  
            //二维码会显示在桌面(你也想显示在桌面的话,要改一下路径)  
            string path = Path.Combine("C:\\\\Users\\\\zhulin\\\\Desktop", di);  
            map.Save(path, ImageFormat.Png);  
            map.Dispose();  
            Response = "二维码生成成功！";  
        }  
        catch (Exception)  
        {  
            Response = "二维码生成失败！";  
        }  
        return Response;  
    }  
}  

}

3.前端

@{
Layout = null;
}