Question

我有一个从

背后的代码填充的asp列表框

    <asp:ListBox ID="UploadsApprovedCountries" EnableViewState="true"  runat="server" Rows="1" AutoPostBack="True" OnSelectedIndexChanged="SelectedCountryChange"></asp:ListBox>

    protected void Load_Countries()
    {
        ListItem ps = new ListItem("Please select", "");
        ps.Value = "";
        UploadsApprovedCountries.Items.Add(ps);



        foreach (string cntry in Countries.CountriesArray())
        {
            UploadsApprovedCountries.Items.Add(new ListItem(cntry, cntry));
        }
    }

在我的Page_Load中，我称之为

        if (!IsPostBack)
        {
            Load_Countries();
        }

并在autopostback上调用此方法

    protected void SelectedCountryChange(object sender, EventArgs e)
    {
        filter = UploadsApprovedCountries.SelectedItem.Value;
        Response.Write("line 589");
    }

然而，我似乎没有做过任何实际调用此方法的事情。从不填充过滤器字符串和＆＃34;行589＆＃34;永远不会被写出来。

任何人都可以帮忙吗

整个我的asp.net页面

asp:Content ContentPlaceHolderID="ContentMainBody" ID="LocalMainBody" runat="server">
<h1> administration</h1>
<div class="clearboth"></div>
    <div>
    <div class="demo">
    <div id="tabs">
        <ul>
        <li><a href="#tabs-1">Uploads awaiting approval</a></li>
        <li><a href="#tabs-3">Uploads approved</a></li>
        <li><a href="#tabs-2">Sign-ups awaiting approval</a></li>
        <li><a href="#tabs-4">Sign-ups approved</a></li>
        <li><a href="#tabs-5">Rejected</a></li>
        </ul>
        <div id="tabs-5">
        <h2>Rejected submissions</h2>
        <div id="rejectedSubmissions" runat="server">

        </div>
        </div>
        <div id="tabs-1">
        <h2>Uploads awaiting approval</h2>
        <div id="matUnautherised" runat="server">
        </div>
         <div class="clearboth"></div>
        </div>
        <div id="tabs-3">
           <h2>Uploads live on site</h2>
        <asp:ListBox ID="UploadsApprovedCountries" EnableViewState="true"  runat="server" Rows="1" AutoPostBack="True" OnSelectedIndexChanged="SelectedCountryChange" OnTextChanged="SelectedCountryChange"></asp:ListBox>
        <div id="matAutherised" runat="server">
        </div>
        <div class="clearboth"></div>
        </div>

        <div id="tabs-2">
        <h2>Sign-ups awaiting approval</h2>
        <div id="signups" runat="server">

        </div>
        <div class="clearboth"></div>
        </div>
        <div id="tabs-4">
        <h2>Sign-ups live on site</h2>
        <div id="signupsapproved" runat="server">


        </div>
        </div>

    </div>
     </div>

      </div>

我刚刚注意到，如果我将列表框中的代码更改为此

            <asp:ListBox ID="UploadsApprovedCountries" EnableViewState="true"  runat="server" Rows="1" AutoPostBack="True" OnSelectedIndexChanged="SelectedCountryChange">
                <asp:ListItem Value="test1" Text="test1"></asp:ListItem>
                <asp:ListItem Value="test2" Text="test2"></asp:ListItem>
                <asp:ListItem Value="test3" Text="test3"></asp:ListItem>
                <asp:ListItem Value="test4" Text="test4"></asp:ListItem>
                <asp:ListItem Value="test5" Text="test5"></asp:ListItem>
            </asp:ListBox>

并且不要从数据源填充它然后它按预期工作。添加后面的代码中的项目和直接添加它们之间有区别吗？

Answer 1

一旦你知道如何

就很简单

    protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);
        Load_Countries();
        UploadsApprovedCountries.EnableViewState = true;
    }

asp：列表框在autopostback上失去价值

1 个答案: