ASP.NET的DropDownList OnSelectedIndexChanged事件不会触发

问题描述：

我试图用一些AJAX和ASP.Net在一起，使我不必刷新整个页面运行的功能，但我已经跨越一个问题，在做这个迷迷糊糊

I'm trying to use some AJAX and ASP.Net together to enable me to run functions without having to refresh the whole page but i've stumbled across a problem in doing this

下面是我的code

<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <asp:DropDownList ID="ddl1" runat="server" OnSelectedIndexChanged="update1" />

        <asp:TextBox runat="server" ID="txt1" />

    </ContentTemplate>
</asp:UpdatePanel>

这是我的code后面

And here's my code behind

 Sub update1(ByVal sender As Object, ByVal e As EventArgs)

    txt1.Text = Now.ToString

End Sub

本次活动不火，因为我没有的AutoPostBack =真在我的DDL，但补充说，到DDL将回发整个页面。

The event doesn't fire because I don't have AutoPostBack="True" on my ddl but adding that to the ddl will postback the whole page.

有没有办法避免使用的AutoPostBack =真，使其只更新面板？

Is there a way to avoid using AutoPostBack="True" so that it only updates the panel?

我知道我可以使用 ASP：按钮来解决这个问题，但我真的很想能够使用一个DDL与 OnSelectedIndexChanged

I know I can use an asp:Button to get around this but i'd really like to be able to use a ddl with OnSelectedIndexChanged

感谢

答

如果你想避免整个视图状态发送给服务器，你应该看看的回调。

If you want to avoid to send the whole viewstate to the server, you should look at callbacks.

相反，如果你想避免整个页面的刷新，但回发，这应该工作：

Instead, if you want to avoid a refresh of the entire page, but with postback, this should work:

<asp:DropDownList ID="ddl1" runat="server" OnSelectedIndexChanged="update1" AutoPostBack="True"  />

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <Triggers>
         <asp:AsyncPostbackTrigger ControlID="ddl1" EventName="SelectedIndexChanged" />
    </Triggers>
    <ContentTemplate>
        <asp:TextBox runat="server" ID="txt1" />
    </ContentTemplate>
</asp:UpdatePanel>

ASP.NET的DropDownList OnSelectedIndexChanged事件不会触发

相关推荐