Bitmap image=new Bitmap((int)Math.Ceiling(checkCode.length*15.0)),25);
执行到这句话时报错
GDI+ limits the maximum height of an image to 65500,图片宽高限制一下
参考 https://stackoverflow.com/questions/1053052/a-generic-error-occurred-in-gdi-jpeg-image-to-memorystream?r=SearchResults