问候！
我在绑定到 XmlDataSources 的 FormView 中有一个 DropDownList：
<asp:FormView ID="MyFormView" runat="server" DataSourceID="MyXmlDataSource">
<ItemTemplate>
<h1><%# XPath("SomeNode")%></h1>
<asp:Label ID="MyLabel" runat="server" AssociatedControlID="MyDdl" Text='<%# XPath("SomeOtherNode")%>' />
<asp:DropDownList ID="MyDdl"
runat="server"
DataSourceID="MyDdlDataSource"
DataTextField="name"
DataValueField="value"
AutoPostBack="true"
OnSelectedIndexChanged="MyDdl_SelectedIndexChanged">
</asp:DropDownList>
</ItemTemplate>
</asp:FormView>
<asp:XmlDataSource ID="MyXmlDataSource" runat="server" XPath="Root/MainSection" />
<asp:XmlDataSource ID="MyDdlDataSource" runat="server" XPath="Root/MainSection/Areas/*" />
在页面的代码隐藏中，我有以下 OnLoad() 方法以及下拉列表的选择索引更改时的方法：
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
if (!IsPostBack)
{
string xml = GetMyXml(0); // default value
MyXmlDataSource.Data = xml;
MyDdlDataSource.Data = xml;
}
}
protected void MyDdl_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList l_MyDdl = FindControl("MyDdl") as DropDownList;
int myVal;
if (l_MyDdl != null)
if (!Int32.TryParse(l_MyDdl.SelectedItem.Value, out myVal))
myVal = 0;
string xml = GetMyXml(myVal);
MyXmlDataSource.Data = xml;
MyDdlDataSource.Data = xml;
}
当从下拉列表中选择不同的值并调用 SelectedIndexChanged 时，我无法获取下拉列表的值（FindControl 始终返回 null）以使用它重新绑定数据源。我怎样才能得到这个值？