[100分]客户端checkboxlist选定项改变事件

我想用javascript根据checkboxlist的选定项中是否有指定项（如“天气”）,来控制一个dropdownlist控件是否显示，不能在后台写，因为不想刷新页面。checkboxlist的datasource是从数据库绑定的，因为数量是动态的，所以不能用checkbox
有没有什么好的实现办法？还请大家多帮忙!

解决方案 »

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asp.net2.0还是以前的？
asp.net2.0可以直接使用Attributes.Add("onclick","jsMethod();return false");实现
ajax，想不刷新用前台控件去改变后台控件，用传统办法行不通
<%@ Page Language="C#" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">  protected void Page_Load( object sender, EventArgs e )
  {
    if (!Page.IsPostBack)
    {
      string[] a = {"A","B"};
      CheckBoxList1.DataSource = a;
      CheckBoxList1.DataBind();
      for (int i = 0 ; i < CheckBoxList1.Items.Count ; i++)
      {
        if (CheckBoxList1.Items[i].Text == "A")
        {
          CheckBoxList1.Items[i].Attributes.Add("onclick", "document.getElementById('" + DropDownList1.ClientID + "').style.display='block'");
        }
        else
        {
          CheckBoxList1.Items[i].Attributes.Add("onclick", "document.getElementById('" + DropDownList1.ClientID + "').style.display='none'");
        }

      }
    }
  }
</script><html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
     <asp:CheckBoxList ID="CheckBoxList1" runat="server">
      </asp:CheckBoxList></div>
      <asp:DropDownList ID="DropDownList1" runat="server">
      </asp:DropDownList>
    </form>
</body>
</html>
<%@ Page Language="C#" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">  protected void Page_Load( object sender, EventArgs e )
  {
    if (!Page.IsPostBack)
    {
      string[] a = { "天气", "B", "C"};
      CheckBoxList1.DataSource = a;
      CheckBoxList1.DataBind();
      for (int i = 0 ; i < CheckBoxList1.Items.Count ; i++)
      {
        if (CheckBoxList1.Items[i].Text == "天气")
        {
          CheckBoxList1.Items[i].Attributes.Add("onclick", "document.getElementById('" + DropDownList1.ClientID + "').style.display='none'");
        }
        else
        {
          CheckBoxList1.Items[i].Attributes.Add("onclick", "document.getElementById('" + DropDownList1.ClientID + "').style.display=''");
        }

      }
    }
  }
</script><html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
     <asp:CheckBoxList ID="CheckBoxList1" runat="server" AutoPostBack="false">
      </asp:CheckBoxList></div>
      <asp:DropDownList ID="DropDownList1" runat="server">
      </asp:DropDownList>
    </form>
</body>
</html>
或者
<%@ Page Language="C#" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">  protected void Page_Load( object sender, EventArgs e )
  {
    if (!Page.IsPostBack)
    {
      string[] a = { "天气", "B", "C"};
      CheckBoxList1.DataSource = a;
      CheckBoxList1.DataBind();
      for (int i = 0 ; i < CheckBoxList1.Items.Count ; i++)
      {
        if (CheckBoxList1.Items[i].Text == "天气")
        {
          CheckBoxList1.Items[i].Attributes.Add("onclick", "if(this.checked) {document.getElementById('" + DropDownList1.ClientID + "').style.display='none'}else{document.getElementById('" + DropDownList1.ClientID + "').style.display=''}");
        }
      }
    }
  }
</script><html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
     <asp:CheckBoxList ID="CheckBoxList1" runat="server" AutoPostBack="false">
      </asp:CheckBoxList></div>
      <asp:DropDownList ID="DropDownList1" runat="server">
      </asp:DropDownList>
    </form>
</body>
</html>
也可以这样<%@ Page Language="C#" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">  protected void Page_Load( object sender, EventArgs e )
  {
    if (!Page.IsPostBack)
    {
      string[] a = { "天气", "B", "C" };
      CheckBoxList1.DataSource = a;
      CheckBoxList1.DataBind();
      for (int i = 0 ; i < CheckBoxList1.Items.Count ; i++)
      {
        CheckBoxList1.Items[i].Attributes.Add("onclick", "ClickMe(this)");
      }
    }
  }
</script><html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
  <title></title>  <script type="text/javascript">
    function ClickMe(o)
    {
      var boxid = "<%=CheckBoxList1.ClientID %>"
      var boxs = document.getElementsByTagName("INPUT")
      for(i = 0;i<boxs.length;i++)
      {
       if(boxs[i].id.substr(0,boxid.length) == boxid)
       {
        var chname = boxs[i].nextSibling.innerHTML

        if(chname == "天气" && boxs[i].checked)
        {
          document.getElementById('<%=DropDownList1.ClientID%>').style.display='none';
          break;
        }
        else
        {
        document.getElementById('<%=DropDownList1.ClientID%>').style.display='';
        }
       }
      }
    }

  </script></head>
<body>
  <form id="form1" runat="server">
    <div>
      <asp:CheckBoxList ID="CheckBoxList1" runat="server" AutoPostBack="false">
      </asp:CheckBoxList></div>
    <asp:DropDownList ID="DropDownList1" runat="server">
    </asp:DropDownList>
  </form>
</body>
</html>随你的需要而定
前台如果用了protected void Page_Load( object sender, EventArgs e )，后台的就被屏蔽了，能把前台的换个名字吗？也让它在初始化页面时执行？
另外因为页面继承了master页，所以没有body,没法用onload事件
OnClick该成OnCheckedChanged事件试试
OnClick该成OnCheckedChanged事件试试
============================
试过，不行
uping............................................................................................小女帮你顶一次
另外因为页面继承了master页，所以没有body,没法用onload事件??
总的页面是有的window.onload=function(){alert("ok")}
服务器端的Page_Load更没有问题