///图片转二进制
private byte[] convertByte(Image img)
{
    MemoryStream ms = new MemoryStream();
    img.Save(ms, img.RawFormat);
    //byte[] bytes = new byte[ms.Length];
    //ms.Read(bytes, 0, Convert.ToInt32(ms.Length));
    //以上两句改成下面两句
    byte[] bytes = ms.ToArray();
    ms.Close();
    return bytes;
}

///二进制生成图片
private Image convertImg(byte[] datas)
{
    MemoryStream ms = new MemoryStream(datas);
    Image img = Image.FromStream(ms, true);
    ms.Close();
    return img;
}