帮我看一下这段代码
SqlParameter[] paras ={ new SqlParameter("@Id", SqlDbType.Int, 4), new SqlParameter("@Name", SqlDbType.NVarChar, 50),new SqlParameter("@Explain", SqlDbType.NVarChar, 80), new SqlParameter("@IsSuccess", SqlDbType.Bit), new SqlParameter("@Vis", SqlDbType.Bit) };
paras[0].Value = nId;
paras[1].Value = txtName;
paras[2].Value = txtExplain;
paras[3].Value = txtSuccess;
paras[4].Value = txtSelect;
SqlHelper.ExcuteNonQurey("UPDATE [Product] set Name=@Name,Explain=@Explain,IsSuccess=@IsSuccess,Vis=@Vis WHERE Id=@Id", CommandType.Text, paras); 说一说这三个参数的作用
BindAD();