ASP: Repeater控件的Items.Count属性始终为零

Question

我对ASP还比较陌生，这个问题让我有点困惑。我有一个重复器（basicInfoReport）与数据源（basicInfo）相连。这部分工作正常；重复器中的Eval调用返回了正确的数据。

我还有一些代码，意图是在页面上设置文本以替换<asp:Literal>。下面分别放了两个片段。

据我所知，重复器正在进行数据绑定（因为Eval调用起作用），所以我无法弄清楚为什么它报告零项，因此foreach语句什么也没做。有人能帮忙吗？ :)

编辑：已解决，请参见更新后的代码。

ASP（删除了不相关的内容）

<asp:AccessDataSource ID="basicInfo" runat="server" 
    DataFile="~/Disasters.accdb" 
    SelectCommand="SELECT * FROM [DisasterTable] WHERE ([ID] = ?)">
    <SelectParameters>
        <asp:QueryStringParameter Name="ID" QueryStringField="ID" Type="Int32" />
    </SelectParameters>
</asp:AccessDataSource>

<asp:Repeater ID="basicInfoReport" runat="server" DataSourceID="basicInfo" 
    onitemdatabound="basicInfoReport_ItemDataBound">
<ItemTemplate>
<h2>Disaster report: <%#Eval("Description")#%></h2>
<b><i>This report is confidential.</i></b><br /><br /><br />

This event was reported on <tt><%#Eval("dateReported")#%></tt>. It was reported  <asp:Literal ID="_wasReportedAnonymously" runat="server"></asp:Literal> and is currently  <asp:Literal ID="_isEmergency" runat="server"></asp:Literal> classed as an emergency.
</ItemTemplate>
</asp:Repeater>

C# (irrelevant stuff removed)

protected void basicInfoReport_ItemDataBound(object sender, RepeaterItemEventArgs e) {

// [...]

// reader refers to an OleDbDataReader that is used for some database interaction in this method.
// until this point, basicInfoReport has not been referenced at all.
if (reader[1].ToString().Equals("False"))
   {

     // at this point basicInfoReport.Items.Count is always zero

     foreach (RepeaterItem repeaterItem in basicInfoReport.Items) {

       // control never makes it this far

       if (repeaterItem.ItemType == ListItemType.Item || repeaterItem.ItemType == ListItemType.AlternatingItem)
          {

             Literal emergencyLiteral = (Literal)repeaterItem.FindControl("_isEmergency");

             emergencyLiteral.Text = "not";
           }
      }
   }

 // [...]

 }

更新: 在almog.ori的帮助下解决了问题。供我参考，这是可用的代码:

C#（删除了不相关的内容）

protected void basicInfoReport_ItemDataBound(object sender, RepeaterItemEventArgs e) {

// [...]

// reader refers to an OleDbDataReader that is used for some database interaction in this method.
// until this point, basicInfoReport has not been referenced at all.
if (reader[1].ToString().Equals("False"))
   {

       if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
          {

             Literal emergencyLiteral = (Literal)e.Item.FindControl("_isEmergency");

             emergencyLiteral.Text = "not";
           }
      }

 // [...]

 }

- Alex Ghiculescu

---

你是在尝试获取项目数量吗？我在你提供的代码中没有找到那行代码。 - Muhammad Akhtar

在这段代码片段中，我并没有出现。但是如果你在注释的地方添加"int count = basicInfoReport.Items.Count"，那么它将等于零（无论我运行时发生了什么）。 - Alex Ghiculescu

Answer 1

你应该查看msdn文档中关于ItemDataBound事件的内容，特别注意事件参数的使用。

      void R1_ItemDataBound(Object Sender, RepeaterItemEventArgs e) {

      // This event is raised for the header, the footer, separators, and items.

      // Execute the following logic for Items and Alternating Items.
      if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) {

事件ItemDataBound会将“行”传递给eventargs。所以你可以对它进行任何操作。您应该查看e.Item.DataItem，这将是绑定项目的数据项。

- almog.ori