<asp:CheckBoxList runat="server" ID="listTest">
</asp:CheckBoxList>
<input type="button" id="btnShow" value="显示选中值" />

if (dt != null && dt.Rows.Count > 0)
{
  foreach (DataRow dr in dt.Rows)
  {
    //分别为text值、value值
    listTest.Items.Add(new ListItem(dr["Title"].ToString(), dr["ID"].ToString()));
  }
}

<table id="listTest" border="0"> 
<tr> 
  <td>
    <input id="listTest_0" type="checkbox" name="listTest$0" />
    <label for="listTest_0">基于jQuery的一个震动效果</label>
  </td> 
  </tr>
<tr> 
  <td><input id="listTest_1" type="checkbox" name="listTest$1" />
    <label for="listTest_1">使用css的overflow属性改变缩略图大小</label>
  </td>
</tr>
</table>

if (dt != null && dt.Rows.Count > 0)
{
  foreach (DataRow dr in dt.Rows)
  {
    //分别为text值、value值
    listTest.Items.Add(new ListItem(dr["Title"].ToString(), dr["ID"].ToString()));
  }
  //为ListItem对象添加alt属性，值保存value值
  foreach (ListItem li in listTest.Items)
  {
    li.Attributes.Add("alt", li.Value);
  }
}

<table id="Table1" border="0"> 
<tr> 
  <td>
    <span alt="400"><input id="listTest_0" type="checkbox" name="listTest$0" />
    <label for="listTest_0">基于jQuery的一个震动效果</label></span>
  </td> 
</tr>
<tr> 
  <td><span alt="398"><input id="listTest_1" type="checkbox" name="listTest$1" />
  <label for="listTest_1">使用css的overflow属性改变缩略图大小</label></span>
  </td>
</tr>
</table>

$(document).ready(function() {
  $("#btnShow").click(function() {
    var valuelist = ""; //保存checkbox选中值
    //遍历name以listTest开头的checkbox
    $("input[name^='listTest']").each(function() {
      if (this.checked) {
        //$(this):当前checkbox对象;
        //$(this).parent("span"):checkbox父级span对象
        valuelist += $(this).parent("span").attr("alt") + ",";
      }
    });
    if (valuelist.length > 0) {
      //得到选中的checkbox值序列,结果为400,398
      valuelist = valuelist.substring(0, valuelist.length - 1);
    }
  });
});