.NET使用ZXing.NET生成中间带图片和不带图片的二维码

基于开源的 ZXing.NET 组件，代码如下：

1、先添加对ZXing.NET的引用，然后添加相应的命名空间：

using System;
using System.Collections.Generic;
using System.Drawing;
using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using ZXing.QrCode.Internal;

2、生成二维码方法类：

 public class QrCodeHelper
    {




        #region  方法一是生成中间不带图片的二维码图片

        /// <summary>
        /// 生成二维码图片
        /// </summary>
        /// <param name="contents">要生成二维码包含的信息</param>
        /// <param name="width">生成的二维码宽度（默认300像素）</param>
        /// <param name="height">生成的二维码高度（默认300像素）</param>
        /// <returns>二维码图片</returns>
        public static Bitmap GeneratorQrImage(string contents, int width = 300, int height = 300)
        {
            if (string.IsNullOrEmpty(contents))
            {
                return null;
            }

            //本文地址：http://www.cnblogs.com/Interkey/p/qrcode.html
            EncodingOptions options = null;
            BarcodeWriter writer = null;
            options = new QrCodeEncodingOptions
            {
                DisableECI = true,
                CharacterSet = "UTF-8",
                Width = width,
                Height = height,
                ErrorCorrection = ErrorCorrectionLevel.H,
            };
            writer = new BarcodeWriter();
            writer.Format = BarcodeFormat.QR_CODE;
            writer.Options = options;

            Bitmap bitmap = writer.Write(contents);
            return bitmap;
        }

        #endregion



        #region  方法二生成中间带图片的二维码图片

        /// <summary>
        /// 生成中间带有图片的二维码图片
        /// </summary>
        /// <param name="contents">要生成二维码包含的信息</param>
        /// <param name="middleImg">要生成到二维码中间的图片</param>
        /// <param name="width">生成的二维码宽度（默认300像素）</param>
        /// <param name="height">生成的二维码高度（默认300像素）</param>
        /// <returns>中间带有图片的二维码</returns>
        public static Bitmap GeneratorQrImage(string contents, Image middleImg, int width = 300, int height = 300)
        {
            if (string.IsNullOrEmpty(contents))
            {
                return null;
            }
            if (middleImg == null)
            {
                //return null;
                return GeneratorQrImage(contents);
            }



            //构造二维码写码器
            MultiFormatWriter mutiWriter = new MultiFormatWriter();
            Dictionary<EncodeHintType, object> hint = new Dictionary<EncodeHintType, object>();
            hint.Add(EncodeHintType.CHARACTER_SET, "UTF-8");
            hint.Add(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

            //生成二维码
            BitMatrix bm = mutiWriter.encode(contents, BarcodeFormat.QR_CODE, width, height, hint);
            BarcodeWriter barcodeWriter = new BarcodeWriter();
            Bitmap bitmap = barcodeWriter.Write(bm);

            //获取二维码实际尺寸（去掉二维码两边空白后的实际尺寸）
            int[] rectangle = bm.getEnclosingRectangle();

            //计算插入图片的大小和位置
            int middleImgW = Math.Min((int)(rectangle[2] / 3.5), middleImg.Width);
            int middleImgH = Math.Min((int)(rectangle[3] / 3.5), middleImg.Height);
            int middleImgL = (bitmap.Width - middleImgW) / 2;
            int middleImgT = (bitmap.Height - middleImgH) / 2;

            //将img转换成bmp格式，否则后面无法创建 Graphics对象
            Bitmap bmpimg = new Bitmap(bitmap.Width, bitmap.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            using (Graphics g = Graphics.FromImage(bmpimg))
            {
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
                g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
                g.DrawImage(bitmap, 0, 0);
            }

            //在二维码中插入图片
            Graphics myGraphic = Graphics.FromImage(bmpimg);
            //白底
            myGraphic.FillRectangle(Brushes.White, middleImgL, middleImgT, middleImgW, middleImgH);
            myGraphic.DrawImage(middleImg, middleImgL, middleImgT, middleImgW, middleImgH);
            return bmpimg;
        }

        #endregion

        






    }

3、简单方法调用实例：

 #region  生成二维码



        public ActionResult QrCode()
        {
            String url = "https://www.cnblogs.com/sharing1986687846";

            Bitmap barcodeBitmap = (Bitmap)Image.FromFile(@"G:MyWebWeb学习WindowsLiveProjectLiveProjectImagespanda.png");

            Bitmap noImgCrCodeBmp=  QrCodeHelper.GeneratorQrImage(url);  //生成中间不带图的二维码


            Bitmap   imgCrCodeBmp= QrCodeHelper.GeneratorQrImage(url, barcodeBitmap);  //生成中间带图的二维码

            MemoryStream  ms=new MemoryStream();

            String imgStr = String.Empty;

            imgStr += String.Format("<br>二维码对应内容:{0}"  />", url);
            
            
            noImgCrCodeBmp.Save(ms, ImageFormat.Png);
            string base64 = Convert.ToBase64String(ms.ToArray());

            imgStr += String.Format("<br>中间不带图:<br><img src="data:image/png;base64,{0}"  />", base64);

            MemoryStream ms1 = new MemoryStream();
            imgCrCodeBmp.Save(ms1, ImageFormat.Png);

            base64 = Convert.ToBase64String(ms1.ToArray());

            imgStr += String.Format("<br>中间带图:<br><img src="data:image/png;base64,{0}"  />", base64);

           


            return Content(imgStr);

        }

         #endregion

效果图如下：

4、中间有图片与没有图片的生成的不一样，原因不清楚，初步以为中间有图片的是因为容错率的原故。

对应的解析代码也很简单：

// create a barcode reader instance
IBarcodeReader reader = new BarcodeReader();
// load a bitmap
Bitmap barcodeBitmap = (Bitmap)Image.FromFile("C:\sample-barcode-image.png");
// detect and decode the barcode inside the bitmap
Result result = reader.Decode(barcodeBitmap);
// do something with the result
if (result != null)
{
    this.txtDecoderType.Text = result.BarcodeFormat.ToString();
    this.txtDecoderContent.Text = result.Text;
}

结语：

其他常用可生成二维码的组件有：QrCode.Net（开源）、ZXing（开源）、ThoughtWorks.QRCode等。

了解了二维码的数据存储后，可以基于这些技术生成富有创意的二维码。