除去生成标准的二维码，还可以生成中间带有Logo的个性化二维码，如下图。 

以下是实现代码。

public void GenerateWithLogo(string text)
        {
            //调用openFileDialog选择要插入的Logo
            openFileDialog.ShowDialog();
            Bitmap logo = new Bitmap(openFileDialog.FileName);
            //调用saveFileDialog选择保存位置
            saveFileDialog.ShowDialog();
            //初始化
            MultiFormatWriter writer = new MultiFormatWriter();
            Dictionary<EncodeHintType, object> hint = new Dictionary<EncodeHintType, object>();
            hint.Add(EncodeHintType.CHARACTER_SET, cbx_code.Text);
            hint.Add(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

            //生成二维码 
            BitMatrix bm = writer.encode(text, BarcodeFormat.QR_CODE, int.Parse(tbx_width.Text), int.Parse(tbx_height.Text), hint);
            BarcodeWriter barcodeWriter = new BarcodeWriter();
            Bitmap map = barcodeWriter.Write(bm);
            //计算尺寸
            int[] rectangle = bm.getEnclosingRectangle();

            //计算插入Logo的大小位置
            int middleW = Math.Min((int)(rectangle[2] / 3.5), logo.Width);
            int middleH = Math.Min((int)(rectangle[3] / 3.5), logo.Height);
            int middleL = (map.Width - middleW) / 2;
            int middleT = (map.Height - middleH) / 2;

            //将img转换成bmp格式，否则后面无法创建Graphics对象
            Bitmap bmpimg = new Bitmap(map.Width, map.Height, 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(map, 0, 0);
            }
            //将二维码插入图片
            Graphics myGraphic = Graphics.FromImage(bmpimg);
            //白底
            myGraphic.FillRectangle(Brushes.White, middleL, middleT, middleW, middleH);
            myGraphic.DrawImage(logo, middleL, middleT, middleW, middleH);

            //保存成图片
            bmpimg.Save(saveFileDialog.FileName, System.Drawing.Imaging.ImageFormat.Png);
            pictureBox.ImageLocation = saveFileDialog.FileName;
        }