string voltage = "9~40vDC";,
将字符串填充到画布中再以image形式输出到本地
g.DrawImage(image, l_intCodeX, l_intCodeY, l_intCodeWidth, l_intCodeHeight);//绘制二维码到画布,留边距20像素
g.DrawString($"供电:{voltage}", new Font("宋体", l_intFontSize, FontStyle.Regular), new SolidBrush(Color.Black), l_intFontX, l_intFontY + (l_intFontInterval * 4)); //绘制文字