SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["byte_img"].ConnectionString);

            conn.Open();

            string sql = "select top 1 * from byte_img order by ID desc";

         

            SqlDataAdapter sda = new SqlDataAdapter(sql.ToString(),conn);

            DataSet ds = new DataSet();

          

            ds.Clear();

            sda.Fill(ds);

            conn.Close();

            DataTable dt = ds.Tables[0];

            byte[] b2 = (byte[])dt.Rows[0]["ImgByte"];

            string type = (string)dt.Rows[0]["ImgType"];

            Response.Clear();

            string Type = checktype(type);

            Response.ContentType = Type; 

          

            byte[] photo = (byte[])dt.Rows[0]["ImgByte"];

            Response.BinaryWrite(b2);

            Response.End();

 //根据文件的扩展名来获取对应的“输出流的HTTP MIME“类型

    private string checktype(string type)

    {

        string ContentType;

        switch (type)

        {

          

             

            case ".gif ":

                ContentType = "image/gif "; break;

            case ".jpg ":

                ContentType = "image/jpeg "; break;

            case "jpeg ":

                ContentType = "image/jpeg "; break;

            case ".png":

              &nb