生成二维码

1.到网上下载 ThoughtWorks.QRCode.dll 到桌面（其他路径也可以，只要你自己知道就行），不用担心，文件很小的。这是生成二维码的dll文件。如果少了后面就没法操作了。

2.控制器

using System.Web.Mvc;
using ThoughtWorks;
using ThoughtWorks.QRCode;
using ThoughtWorks.QRCode.Codec;
using ThoughtWorks.QRCode.Codec.Data;
using System.Drawing;
using System.IO;
using System.Text;
public string CreateQRCode(string text)
        {
            QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
            qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
            qrCodeEncoder.QRCodeScale = 4;
            qrCodeEncoder.QRCodeVersion = 8;
            qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
            System.Drawing.Image image = qrCodeEncoder.Encode(text, Encoding.UTF8);
            string targetFilePath = Path.Combine(Request.MapPath("~/image/"));
            if (!Directory.Exists(targetFilePath))//文件夹不存在的时候创建
            {
                Directory.CreateDirectory(targetFilePath);
            }
            string filename = DateTime.Now.ToString("yyyymmddhhmmssfff").ToString() + ".jpg";
            string filepath = Server.MapPath(@"~/image/") + filename;
            System.IO.FileStream fs = new System.IO.FileStream(filepath, System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.Write);
            image.Save(fs, System.Drawing.Imaging.ImageFormat.Jpeg);

            fs.Close();
            image.Dispose();
            return filename;
        }

3.html

<div>
    <table>
        <tr>
            <td><img id="imgs" /></td>
        </tr>
        <tr>
            <td><input id="text" /></td>
        </tr>
        <tr>
            <td><button type="button" style="height:30px;100px" onclick="generateQRCord(this)">生成二维码</button></td>
        </tr>
    </table>
</div>

<script>
    function generateQRCord(obj) {
        var text = $("#text").val();
        $.post("/Home/CreateQRCode", { text: text }, function (data) {
            $("#imgs").attr("src", "/image/" + data);
        })
    }
</script>