c# 生成二维码

http://www.cnblogs.com/Soar1991/archive/2012/03/30/2426115.html

QRCode 项目地址：http://qrcodenet.codeplex.com/

ASP.NET 输出二维码图片

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Gma.QrCodeNet.Encoding;
using Gma.QrCodeNet.Encoding.Windows.Render;
using System.Drawing;
using System.IO;
using System.Drawing.Imaging;

protected void Page_Load(object sender, EventArgs e)
        {
            var str = Request.QueryString["qrCode"] ?? "http://www.baidu.com";
            QrEncoder qrEncoder = new QrEncoder(ErrorCorrectionLevel.H);
            QrCode qrCode = new QrCode();
            qrEncoder.TryEncode(str, out qrCode);

            var codeSize = new FixedCodeSize(100, QuietZoneModules.Zero); // 图片大小
            var codeSize2 = new FixedModuleSize(2, QuietZoneModules.Two); // 图片大小
            GraphicsRenderer gRenderer = new GraphicsRenderer(
                            codeSize,
                            Brushes.Black, Brushes.White);
            MemoryStream ms = new MemoryStream();
            gRenderer.WriteToStream(qrCode.Matrix, ImageFormat.Png, ms);

            var bytes = ms.GetBuffer();
            
            Response.ContentType = "image/png";
            Response.BinaryWrite(bytes);
            Response.End();
        }