连接列表项(checkboxItem)和数据集行使用linq

我有问题，我试图加入listtitem (checkboxItem)和数据集行使用linq使listtitem (checkboxItem)在选定

private void BindCheckboxList()
{
    int resID = Convert.ToInt32(hf_resID.Value);
    DataSet skillDS = Skill.GetSkillsForResousrce(resID);

    //checked pre selected items 
    var query = from ListItem li in chblSkills.Items
                join dsRow in skillDS.Tables[0].Rows
                on li.Value equals ds
                select ListItem;
    foreach (ListItem li in query)
        ListItem.selected = true;
}

    var query = from ListItem li in chblSkills.Items
            from dsRow in skillDS.Tables[0].Rows
            where li.Value == dsRow["ColumnName"]
            select ListItem