调用Zebra打印只能打印部分，设置Bitmap大小没用

Question

            //开始绘制图片
            int initialWidth =1200, initialHeight = 600;
            Bitmap theBitmap = new Bitmap(initialWidth, initialHeight);
            Graphics theGraphics = Graphics.FromImage(theBitmap);
            Brush bush = new SolidBrush(System.Drawing.Color.Black);//填充的颜色
                                                                    //呈现质量
            //theGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.Default;
            //背景色
            theGraphics.Clear(System.Drawing.Color.FromArgb(120, 240, 180));
            System.Drawing.Font myFont;
            myFont = new System.Drawing.Font("宋体", 18, FontStyle.Bold)


            int totalbytes = 720000;
            int rowbytes = 900;
            string hex = ZebraUnity.BmpToZpl(theBitmap, out totalbytes, out rowbytes);//将图片转成ASCii码
            string mubanstring = "~DGR:ZLOGO.GRF," + totalbytes.ToString() + "," + rowbytes.ToString() + "," + hex;//将图片生成模板指令
            //readerCamera2.CameraSendMessage(mubanstring);//利用TCP/IP发送模板指令到打印机
            //return hex;

            string otherstring = "^XA^FO0,0^XGR:ZLOGO.GRF,1,1^FS";//调用该模板指令
            otherstring += "^XZ";
            return mubanstring + otherstring;

怎么设置 initialWidth和initialHeight 的值都没有用？设置Bitmap的大小不起作用的。标签纸打不全，只能打部分，右边的二维码打不出来？是什么原因？
使用斑马打印机rowbytes每行的字节数是什么意思？