本文將介紹在 Click DataList 中的 Button 後，如何取得 ItemTemplate 中其他控制項的內容？
今天在論壇上看到有網友討論到 Click DataList 中的 Button 後，如何取得 ItemTemplate 中其他控制項的內容？一般筆者都是這樣做的。首先先將 Button 的 CommandName 設定為 Select，不需要額外在 Button Click 事件中寫任何程式碼。
1: <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="DataListDemo.aspx.cs" Inherits="Demo.DataListDemo" %>
2:
3: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
4:
5: <html xmlns="http://www.w3.org/1999/xhtml">
6: <head runat="server">
7: <title></title>
8: </head>
9: <body>
10: <form id="form1" runat="server">
11: <div>
12: <asp:DataList ID="DataList1" runat="server" DataKeyField="RegionID"
13: DataSourceID="SqlDataSource1"
14: onselectedindexchanged="DataList1_SelectedIndexChanged">
15: <ItemTemplate>
16: RegionID:
17: <asp:Label ID="RegionIDLabel" runat="server" Text='<%# Eval("RegionID") %>' />
18: <br />
19: RegionDescription:
20: <asp:Label ID="RegionDescriptionLabel" runat="server"
21: Text='<%# Eval("RegionDescription") %>' />
22: <br />
23: <asp:Button ID="Button1" runat="server" CommandName="select"
24: Text="Button" />
25: <br />
26: <br />
27: </ItemTemplate>
28: </asp:DataList>
29: <asp:SqlDataSource ID="SqlDataSource1" runat="server"
30: ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
31: SelectCommand="SELECT [RegionID], [RegionDescription] FROM [Region]">
32: </asp:SqlDataSource>
33: </div>
34: </form>
35: </body>
36: </html>
經過上述設定，當位於 DataList 中的 Button 被 Click 後會觸發 DataList 的 SelectedIndexChanged 事件，因此我們可以在這個事件中透過 SelectedIndex 屬性來取得該項目（Item）中的任何控制項。程式碼如下：
1: using System;
2: using System.Collections.Generic;
3: using System.Linq;
4: using System.Web;
5: using System.Web.UI;
6: using System.Web.UI.WebControls;
7:
8: namespace Demo
9: {
10: public partial class DataListDemo : System.Web.UI.Page
11: {
12: protected void Page_Load(object sender, EventArgs e)
13: {
14:
15: }
16:
17: protected void DataList1_SelectedIndexChanged(object sender, EventArgs e)
18: {
19: string dataKey = DataList1.DataKeys[DataList1.SelectedIndex].ToString();
20: Label RegionIDLabel = DataList1.Items[DataList1.SelectedIndex].FindControl("RegionIDLabel") as Label;
21: Label RegionDescriptionLabel = DataList1.Items[DataList1.SelectedIndex].FindControl("RegionDescriptionLabel") as Label;
22: Response.Write(string.Format("{0},{1},{2}", dataKey, RegionIDLabel.Text, RegionDescriptionLabel.Text));
23: }
24: }
25: }