QrCode.Net 生成二维码图片

　　QrCode.Net  0.4.0

　　最近实现.net生成二维码。如果二维码png图片不存在，则使用第三方库QrCode.Net生成二维码png图片保存到服务器上，然后返回该二维码的生成路径（因为生成png图片的路径，是根据参数归类到**年文件夹 下的**月文件夹 下的 **日文件夹下，所以要根据参数找对应的二维码图片路径）

1.打开 程序包管理器 控制台，在窗口中 输入  Install-Package QrCode.Net，就可以通过 nuget获取到 QrCode.Net  0.4.0 dll包。

2.新建类，添加引用。

using Gma.QrCodeNet.Encoding;
using Gma.QrCodeNet.Encoding.Windows.Render;

3.该类实现代码如下。

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using Gma.QrCodeNet.Encoding;
using Gma.QrCodeNet.Encoding.Windows.Render;

namespace CYP2014.Shd.Common
{
    public class GenerateImage
    {
        private static readonly CYPLog.TextLogger _generateImage = CYPLog.TextLogManager.Create(typeof (GenerateImage));

        /// <summary>
        /// 获取分享到微信二维码图片路径,如果图片不存在，则生成二维码png图片
        /// </summary>
        /// <param name="tradeCode">车辆编码</param>
        /// <param name="wayTag">检测报告导入平台  1  PC端   2 WCF   默认为1</param>
        /// <returns>二维码图片路径</returns>
        public static string GetImage(string tradeCode, int wayTag = 1)
        {
            try
            {
                if (string.IsNullOrEmpty(tradeCode))
                {
                    return "";
                }

                //图片路径  
                string fileName = tradeCode.Trim() + ".png";
                string secondFolder = "/WeChatImg";

                string subYearMonth = tradeCode.Substring(3, 5);
                int yearNum = 0;
                int dayNum = 0;
                int.TryParse(subYearMonth.Substring(0, 2), out yearNum);
                int.TryParse(subYearMonth.Substring(2, 3), out dayNum);
                int.TryParse("20" + yearNum, out yearNum);

                //声明日期
                var date = new DateTime();
                date = date.AddYears(yearNum).AddYears(-1);
                date = date.AddDays(dayNum).AddDays(-1);
                secondFolder = string.Format("{0}\{1}\{2}\{3}\", secondFolder, yearNum, date.Month, date.Day);
                string tagFolder = System.Web.Hosting.HostingEnvironment.MapPath("~" + secondFolder);
                if (!Directory.Exists(tagFolder))
                {
                    Directory.CreateDirectory(tagFolder);
                }

                string newfilename = tagFolder + fileName;
                if (!File.Exists(newfilename))
                {
                    //请求 下载图片
                    //var httpWebRequest = WebRequest.Create(url);
                    //var httpWebResponse = httpWebRequest.GetResponse();
                    //var stream = httpWebResponse.GetResponseStream();
                    //var bitmap = (Bitmap) Image.FromStream(stream);
                    ////保存图片文件  
                    //bitmap.Save(newfilename, System.Drawing.Imaging.ImageFormat.Png);

                    string url = string.Format(@"{0}Share/Report.aspx?tradecode={1}&waytag={2}", Config.MobileServiceUrl,
                        tradeCode, wayTag);
                    GenQrCode(newfilename, url);
                }
                return string.Concat(Config.VirtualDirectory, secondFolder, fileName);
            }
            catch (Exception ex)
            {
                _generateImage.Info(string.Format(
                    "GenerateImage.GetImage异常。参数：tradeCode=【{0}】,wayTag=【{1}】。异常信息：【{2}】", tradeCode, wayTag,
                    ex.ToString()));
                return string.Empty;
            }
        }

        /// <summary>
        /// 生成二维码，并保存图片到指定路径下
        /// </summary>
        /// <param name="fileName">图片保存路径全名（包括路径和文件名）</param>
        /// <param name="content">要生成二维码的内容</param>
        public static void GenQrCode(string fileName, string content)
        {
            try
            {
                var qrEncoder = new QrEncoder(ErrorCorrectionLevel.H);
                var qrCode = qrEncoder.Encode(content);
                var gRender = new GraphicsRenderer(new FixedModuleSize(5, QuietZoneModules.Two));

                using (var stream = new FileStream(fileName, FileMode.Create))
                {
                    gRender.WriteToStream(qrCode.Matrix, ImageFormat.Png, stream, new Point(600, 600));
                }

            }
            catch (Exception ex)
            {
                _generateImage.Info(
                    string.Format(
                        "GenerateImage.GenQrCode异常。参数：content=【{0}】,fileName=【{1}】。异常信息：【{2}】", content, fileName,
                        ex.ToString()));
            }

        }
    }
}