将Filter Expression动态添加到Gridview以过滤两列

Please see the following code:

请参阅以下代码：

protected void CheckBoxList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        SqlDataSource1.FilterExpression = "";
        foreach (ListItem l in CheckBoxList1.Items)
        {
            if (l.Selected)
            {
                HD1.Value += l.Value + ",";
                if (SqlDataSource1.FilterExpression == "")
                    SqlDataSource1.FilterExpression += " TSOType like '" + l.Value + "%'";
                else
                {
                    SqlDataSource1.FilterExpression += "or TSOType like '" + l.Value + "%'";
                }

            }
        }
    }
pro