C#生成二維碼，把二維碼圖片放入Excel中

  /// <summary>
        /// 把圖片保存到excel中
        /// </summary>
        /// <param name="excelFilePath">目標Excel</param>
        /// <param name="imageFilePath">保存的圖片</param>
        /// <param name="width">保存時圖片寬度</param>
        /// <param name="height">保存時圖片高度</param>
        /// <param name="col">Excel第幾列開始放</param>
        /// <param name="row">Excel第幾行開始放</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();//原圖大小

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

　　生成二維碼

 /// <summary>
        /// 生成二維碼圖片
        /// </summary>
        /// <param name="codeNumber">要生成二維碼的字符串</param>     
        /// <param name="size">大小尺寸</param>
        /// <returns>二維碼圖片</returns>
        public Bitmap Create_ImgCode(string codeNumber, int size)
        {
            //創建二維碼生成類
            QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
            //設置編碼模式
            qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
            //設置編碼測量度
            qrCodeEncoder.QRCodeScale = size;
            //設置編碼版本
            qrCodeEncoder.QRCodeVersion = 0;
            //設置編碼錯誤糾正
            qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
            //生成二維碼圖片
            System.Drawing.Bitmap image = qrCodeEncoder.Encode(codeNumber);
            return image;
        }

　　用上面方法生成二維碼有個問題，當數據量特別大的時候就生成不了。后面換了zxing來生成二維碼，生成的數據多一點

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

            options = new QrCodeEncodingOptions
            {
                DisableECI = true,
                CharacterSet = "UTF-8",
                Margin = 0,
                Width = 125,
                Height = 125
            };
            writer = new BarcodeWriter();
            writer.Format = BarcodeFormat.QR_CODE;
            writer.Options = options;
            return writer.Write(str);
        }

生成出來的二維碼有可能周圍的空白處有點多，初步測試可能是由於信息量過大，二維碼如果按照原始塊間距生成的話會導致超過固定的大小，因此自動減小塊間距導致生成的沒有固定大小大，留有空白

利用儀器掃描一張圖片中某個部分含有二維碼，如果圖片過大，我遇到過3000*2400左右大小的，用二維碼解析根本解析不出來，只有按照二維碼的位置進行剪切裁剪后再解析二維碼，能實現

  /// <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 * 3 / 4;
            int startY = 0;
            int width = b.Width / 4;
            int height = b.Height / 4;
            try
            {
                Bitmap bmpOut = new Bitmap(width, height, PixelFormat.Format24bppRgb);
                Graphics g = Graphics.FromImage(bmpOut);
                g.DrawImage(b, new Rectangle(0, 0, 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">開始坐標X</param>
        /// <param name="StartY">開始坐標Y</param>
        /// <param name="iWidth">寬度</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(0, 0, iWidth, iHeight), new Rectangle(StartX, StartY, iWidth, iHeight), GraphicsUnit.Pixel);
                g.Dispose();
                return bmpOut;
            }
            catch
            {
                return null;
            }
        }