string sqlText = "select pic,msg from WapPushMsg where id = " + id;
            Odbc o = new Odbc();
            byte[] photo = null;
            using (OdbcDataReader dr = o.ExecuteReader(sqlText))
            {
                if (dr.Read())
                {
                    msgView.Text = dr[1].ToString();
                    if (!dr.IsDBNull(0))
                    {
                        photo = (Byte[])dr[0];                        
                    }
                    else
                    {

                    }
                }
            }

private void LoadImage(string fileName)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                string sql = "select blobdata from Image where ImageFileName like @filename";
                 SqlCommand cmd = new SqlCommand(sql, conn);
                 cmd.Parameters.Add("@filename", SqlDbType.Text);
                 cmd.Parameters["@filename"].Value = fileName;

                 conn.Open();

                object objImage = cmd.ExecuteScalar();

                byte[] buffer = (byte[])objImage;

                 BinaryWriter bw = new BinaryWriter(new FileStream("C:\\abcd.png", FileMode.Create));
                 bw.Write(buffer);
                 bw.Close();
               MemoryStream ms = new MemoryStream(buffer);
                 Image bgImage = Image.FromStream(ms);
                 ms.Close();
                this.BackgroundImage = bgImage;
             }
            
         }

------解决方案--------------------
pic字段类型是二进制的吗