javascript – 如何使用jQuery过滤DropDownList中的选项

我有2个DropDownList.first DropDownList有4个选项.Second DropDownList有20个选项.我想在第一个DropDownList中选择值为1的选项时我在第二个DropDownList中显示所有元素,如果在第一个DropDownList中选择了值为2的选项我展示了一些第二个DropDownList选项,等等.我如何使用jQuery来做到这一点

编辑1)

代码是：

<div>
    <asp:DropDownList ID="DropDownList1" runat="server" Height="72px" Width="184px">
        <asp:ListItem Value="1">All</asp:ListItem>
        <asp:ListItem Value="2">Apples</asp:ListItem>
        <asp:ListItem Value="2">Orange</asp:ListItem>
        <asp:ListItem Value="3">Onion</asp:ListItem>
    </asp:DropDownList>
    <br />
    <asp:DropDownList ID="DropDownList2" runat="server" Height="18px" Width="187px">
        <asp:ListItem Value="Apple_Style_1">Apple Style 1</asp:ListItem>
        <asp:ListItem Value="Apple_Style_2">Apple Style 2</asp:ListItem>
        <asp:ListItem Value="Apple_Style_3">Apple Style 3</asp:ListItem>
        <asp:ListItem Value="Orange_Style_1">Orange Style 1</asp:ListItem>
        <asp:ListItem Value="Orange_Style_2">Orange Style 2</asp:ListItem>
        <asp:ListItem Value="Orange_Style_3">Orange Style 3</asp:ListItem>
        <asp:ListItem Value="Orange_Style_4">Orange Style 4</asp:ListItem>
        <asp:ListItem Value="Onion_Style_1">Onion Style 1</asp:ListItem>
        <asp:ListItem Value="Onion_Style_2">Onion Style 2</asp:ListItem>
    </asp:DropDownList>
</div>

解决方法:

你可以尝试这个jsfiddle：http://jsfiddle.net/Chran/1/

HTML

<div>
<select ID="DropDownList1" Height="72px" Width="184px">
    <option Value="1">All</option>
    <option Value="2">Apples</option>
    <option Value="2">Orange</option>
    <option Value="3">Onion</option>
</select>
<br />
<select ID="DropDownList2" Height="18px" Width="187px">
    <option Value="Apple_Style_1">Apple Style 1</option>
    <option Value="Apple_Style_2">Apple Style 2</option>
    <option Value="Apple_Style_3">Apple Style 3</option>
    <option Value="Orange_Style_1">Orange Style 1</option>
    <option Value="Orange_Style_2">Orange Style 2</option>
    <option Value="Orange_Style_3">Orange Style 3</option>
    <option Value="Orange_Style_4">Orange Style 4</option>
    <option Value="Onion_Style_1">Onion Style 1</option>
    <option Value="Onion_Style_2">Onion Style 2</option>
</select>
</div>​

JavaScript的

var options = $("#DropDownList2").html();
$("#DropDownList1").change(function(e) {
    var text = $("#DropDownList1 :selected").text();
    $("#DropDownList2").html(options);
    if(text == "All") return;
    $('#DropDownList2 :not([value^="' + text.substr(0, 3) + '"])').remove();
});​

根据ASP.Net Control Id,您必须更改Id.

希望这对你有所帮助.