读取图片到picturebox

private void ShowImage(string sql)

        {

            SqlConnection conn = new SqlConnection( "Data Source=10.118.15.249;Asynchronous Processing=true;Initial Catalog=test_att;User ID=kqgluser;Password=tlgdh");

            //调用方法如：

　　　 ShowImage("select Photo from UserPhoto where UserNo='" + userno +"'");

            SqlCommand cmd = new SqlCommand(sql, conn);

            conn.Open();

            byte[] b = (byte [])cmd.ExecuteScalar();

            if (b.Length > 0)

            {

                MemoryStream stream = new MemoryStream(b, true);

                stream.Write(b, 0, b.Length);

                pbPhoto11.Image = new Bitmap (stream);

                stream.Close();

            }

            conn.Close();

        }