在Repeater控件中DropDownList,无法触发SelectedIndexChanged

Question

我有一个转发器控件,在页脚中我有一个DropDownList.在我的代码隐藏中,我有:

protected void ddMyRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item
            || e.Item.ItemType == ListItemType.AlternatingItem)
    {
       // Item binding code
    }

    else if (e.Item.ItemType == ListItemType.Footer)
    {
        DropDownList ddl = e.Item.FindDropDownList("ddMyDropDownList");
        // Fill the list control
        ddl.SelectedIndexChanged += new  
           EventHandler(ddMyDropDownList_SelectedIndexChanged);
        ddl.AutoPostBack = true;
    }
 }

页面显示为PostBack但是我的EventHandler没有被调用.有任何想法吗？

Answer 1

如果你只想激活OnSelectedIndexChanged,它应该是这样的:

Page.aspx - 来源

<FooterTemplate>
    <asp:DropDownList ID="ddlOptions"
             runat="server" 
             AutoPostBack="true" 
             onselectedindexchanged="ddlOptions_SelectedIndexChanged">
        <asp:ListItem>Option1</asp:ListItem>
        <asp:ListItem>Option2</asp:ListItem>
    </asp:DropDownList>
</FooterTemplate>

Page.aspx.cs - 代码隐藏

protected void ddlOptions_SelectedIndexChanged(object sender, EventArgs e)
    {
        //Event Code here.
    }

就是这样.不需要更多.

Answer 2

如果DropDownList在Repeater中,然后激活SelectIndexChanged事件,则需要在GridView/Repeater上禁用EnableViewState.

例如

EnableViewState="false"

您还需要在每个回发上对GridView/Repeater进行数据绑定,以便在Page Load方法中对其进行数据绑定.