C#生成二维码，把二维码图片放入Excel中

  /// <summary>
        /// 把图片保存到excel中
        /// </summary>
        /// <param name="excelFilePath">目标Excel</param>
        /// <param name="imageFilePath">保存的图片</param>
        /// <param name="width">保存时图片宽度</param>
        /// <param name="height">保存时图片高度</param>
        /// <param name="col">Excel第几列开始放</param>
        /// <param name="row">Excel第几行开始放</param>
        public static void InsertImgToExcel(string excelFilePath, string imageFilePath,int width,int height,int col,int row)
        {
            try
            {
                FileStream fs = new FileStream(excelFilePath, FileMode.Open, FileAccess.ReadWrite);
                HSSFWorkbook hssfworkbook = new HSSFWorkbook(fs);
                ISheet sheet1 = hssfworkbook.GetSheetAt(0);

                //map the path to the img folder
                string imagesPath = imageFilePath;
                //create an image from the path
                System.Drawing.Image image = System.Drawing.Image.FromFile(imagesPath);
                MemoryStream ms = new MemoryStream();
                //pull the memory stream from the image (I need this for the byte array later)
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
                //the drawing patriarch will hold the anchor and the master information
                IDrawing patriarch = sheet1.CreateDrawingPatriarch();
                //store the coordinates of which cell and where in the cell the image goes
                HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 100, 100, col, row, col+3, row+3);
                //types are 0, 2, and 3. 0 resizes within the cell, 2 doesn't
                anchor.AnchorType = 2;
                //add the byte array and encode it for the excel file
                int index = hssfworkbook.AddPicture(ms.ToArray(), PictureType.JPEG);
                IPicture pict = patriarch.CreatePicture(anchor, LoadImage(imagesPath, hssfworkbook));
                pict.Resize();//原图大小

                FileStream fs3 = new FileStream(excelFilePath, FileMode.OpenOrCreate);
                hssfworkbook.Write(fs3);
                fs3.Close();
                fs.Close();
}

　　生成二维码

 /// <summary>
        /// 生成二维码图片
        /// </summary>
        /// <param name="codeNumber">要生成二维码的字符串</param>
        /// <param name="size">大小尺寸</param>
        /// <returns>二维码图片</returns>
        public Bitmap Create_ImgCode(string codeNumber, int size)
        {
            //创建二维码生成类
            QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
            //设置编码模式
            qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
            //设置编码测量度
            qrCodeEncoder.QRCodeScale = size;
            //设置编码版本
            qrCodeEncoder.QRCodeVersion = 0;
            //设置编码错误纠正
            qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
            //生成二维码图片
            System.Drawing.Bitmap image = qrCodeEncoder.Encode(codeNumber);
            return image;
        }

　　用上面方法生成二维码有个问题，当数据量特别大的时候就生成不了。后面换了zxing来生成二维码，生成的数据多一点

 public static Bitmap Create(string str)
         {
             EncodingOptions options = null;
             BarcodeWriter writer = null;

             options = new QrCodeEncodingOptions
             {
                 DisableECI = true,
                 CharacterSet = "UTF-8",
                 Margin = ,
                 Width = ,
                 Height =
             };
             writer = new BarcodeWriter();
             writer.Format = BarcodeFormat.QR_CODE;
             writer.Options = options;
             return writer.Write(str);
         }

生成出来的二维码有可能周围的空白处有点多，初步测试可能是由于信息量过大，二维码如果按照原始块间距生成的话会导致超过固定的大小，因此自动减小块间距导致生成的没有固定大小大，留有空白

利用仪器扫描一张图片中某个部分含有二维码，如果图片过大，我遇到过3000*2400左右大小的，用二维码解析根本解析不出来，只有按照二维码的位置进行剪切裁剪后再解析二维码，能实现

  /// <summary>
        /// 剪裁 -- 用GDI+
        /// </summary>
        /// <param name="b">原始Bitmap</param>
        /// <returns>剪裁后的Bitmap</returns>
        public static Bitmap Cut(Bitmap b)
        {
            if (b == null)
            {
                return null;
            }
            int startX = b.Width *  / ;
            int startY = ;
            int width = b.Width / ;
            int height = b.Height / ;
            try
            {
                Bitmap bmpOut = new Bitmap(width, height, PixelFormat.Format24bppRgb);
                Graphics g = Graphics.FromImage(bmpOut);
                g.DrawImage(b, new Rectangle(, , width, height), new Rectangle(startX, startY, width, height), GraphicsUnit.Pixel);
                g.Dispose();
                return bmpOut;
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 剪裁 -- 用GDI+
        /// </summary>
        /// <param name="b">原始Bitmap</param>
        /// <param name="StartX">开始坐标X</param>
        /// <param name="StartY">开始坐标Y</param>
        /// <param name="iWidth">宽度</param>
        /// <param name="iHeight">高度</param>
        /// <returns>剪裁后的Bitmap</returns>
        public static Bitmap Cut(Bitmap b, int StartX, int StartY, int iWidth, int iHeight)
        {
            if (b == null)
            {
                return null;
            }
            int w = b.Width;
            int h = b.Height;
            if (StartX >= w || StartY >= h)
            {
                return null;
            }
            if (StartX + iWidth > w)
            {
                iWidth = w - StartX;
            }
            if (StartY + iHeight > h)
            {
                iHeight = h - StartY;
            }
            try
            {
                Bitmap bmpOut = new Bitmap(iWidth, iHeight, PixelFormat.Format24bppRgb);
                Graphics g = Graphics.FromImage(bmpOut);
                g.DrawImage(b, new Rectangle(, , iWidth, iHeight), new Rectangle(StartX, StartY, iWidth, iHeight), GraphicsUnit.Pixel);
                g.Dispose();
                return bmpOut;
            }
            catch
            {
                return null;
            }
        }