Stream与byte[]与Image与string

        public byte[] GetByteImage(Image img)
        {
            byte[] bt = null;
            if (!img.Equals(null))
            {
                using (MemoryStream mostream = new MemoryStream())
                {
                    Bitmap bmp = new Bitmap(img);
                    bmp.Save(mostream, System.Drawing.Imaging.ImageFormat.Bmp);//将图像以指定的格式存入缓存内存流
                    bt = new byte[mostream.Length];
                    mostream.Position = ;//设置留的初始位置
                    mostream.Read(bt, , Convert.ToInt32(bt.Length));
                }
            }
            return bt;
        }