是谁看一下这段代码。我从数据库读图片的二进制流，转化为图片并显示

Question

                DataTable dt = sql.ExecuteSqlSelect("select Image from Image where id=1 ");
                foreach (DataRow dr in dt.Rows)
                {
                    string str = dr["Image"].ToString();
                    int i = str.Length;
                    if (dr["Image"].ToString() == null && dr["Image"].ToString()=="")
                    {
                    }
                    else{
                        MemoryStream buf = new MemoryStream((byte[]) dr[0]);                        Image image = Image.FromStream(buf, true);                        pictureBox1.Image = image;
                  
                    }
                }
            }
            catch (SqlException ee)
            {
                Console.WriteLine(ee.Message);
            }
        }
这样写总是报参数错误的错误提示。谁知道是怎么回事？