ASP.NET - 控制事件不会在中继器内部烧毁 [英] ASP.NET - Control Events Not Firing Inside Repeater

问题描述

这是一个荒谬的常见问题，耗尽了所有明显的解决方案，我希望SO可以为我提供一些输入...我在一个页面中有一个UserControl，它包含一个包含多个控件的中继器，导致回发。麻烦的是，中继器内部的所有控件在回发时都不会触发他们的事件处理程序，但在中继器之外的控制（仍在UC中）被正确处理。我已经确保我的控件没有被重新生成，因为如果（！IsPostBack）缺少，并且我验证了Request.Form [__ EVENTTARGET]包含正确的控件ID在Page_Load事件中。我试图在一个单独的项目中重现症状，它的工作正常。

This is a absurdly common issue and having exhausted all of the obvious solutions, I'm hoping SO can offer me some input... I have a UserControl inside a page which contains a repeater housing several controls that cause postback. Trouble is, all of the controls inside of the repeater never hit their event handlers when they postback, but controls outside of the repeater (still in the UC) are correctly handled. I already made sure my controls weren't being regenerated due to a missing if(!IsPostBack) and I verified that Request.Form["__EVENTTARGET"] contained the correct control ID in the Page_Load event. I attempted to reproduce the symptoms in a separate project and it worked as it should.

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="NoteListControl.ascx.cs"
    Inherits="SantekGBS.Web.UserControls.NoteListControl" %>

<asp:UpdatePanel ID="upNotes" runat="server" UpdateMode="Conditional">
    <ContentTemplate>
        <div class="NoteList" id="divNoteList" runat="server">
            <asp:Repeater ID="repNotes" runat="server">
                <HeaderTemplate>
                    <table width="98%" cellpadding="3" cellspacing="0">
                </HeaderTemplate>
                <ItemTemplate>
                    <tr class="repeaterItemRow">
                        <asp:ImageButton ID="ImageButton1" runat="server" ImageUrl="~/Content/images/DeleteIcon.gif"
                            OnClick="ibRemove_Click" CommandArgument='<%# Container.ItemIndex %>' CommandName='<%# Eval("ID") %>'
                            CausesValidation="false" AlternateText="Delete" />
                        <%# Eval("Text") %></td>
                    </tr>
                </ItemTemplate>
                <FooterTemplate>
                    </table>
                </FooterTemplate>
            </asp:Repeater>
            <asp:PlaceHolder ID="phNoNotes" runat="server" Visible="false">
                <div class="statusMesssage">
                    No notes to display.
                </div>
            </asp:PlaceHolder>
        </div>
    </ContentTemplate>
</asp:UpdatePanel>

---

---

public partial class NoteListControl : UserControl
{
    [Ninject.Inject]
    public IUserManager UserManager { get; set; }

    protected List<Note> Notes
    {
        get
        {
            if (ViewState["NoteList"] != null)
                return (List<Note>)ViewState["NoteList"];
            return null;
        }
        set { ViewState["NoteList"] = value; }
    }

    public event EventHandler<NoteEventArgs> NoteAdded;
    public event EventHandler<NoteEventArgs> NoteDeleted;
    public event EventHandler<NoteEventArgs> NoteChanged;

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            UtilityManager.FillPriorityListControl(ddlPriority, false);
        }
    }

    protected void ibRemove_Click(object sender, ImageClickEventArgs e)
    {
        System.Diagnostics.Debug.WriteLine("ibRemove POSTBACK"); // This is NEVER hit
    }

    public void Fill(List<Note> notes)
    {
        Notes = notes;
        RefreshRepeater();
    }

    private void RefreshRepeater()
    {
        if (Notes != null && Notes.Any())
        {
            var sorted = Notes.OrderByDescending(n => n.Timestamp);
            Notes = new List<Note>();
            Notes.AddRange(sorted);
            repNotes.Visible = true;
            phNoNotes.Visible = false;
            repNotes.DataSource = Notes;
            repNotes.DataBind();
        }
        else
        {
            repNotes.Visible = false;
            phNoNotes.Visible = true;
        }
    }
}

public class NoteEventArgs : EventArgs
{
    public Note Note { get; set; }
    public NoteEventArgs()
    { }
    public NoteEventArgs(Note note)
    {
        this.Note = note;
    }
}

代码是故意缺少的功能，所以只要忽略这个事实

The code is intentionally missing functionality so just disregard that fact.

推荐答案

您编辑的代码中有 CommandArgument 和 CommandName 属性;您是否真正处理 Repeater.ItemCommand 事件？

Your edited code has residual CommandArgument and CommandName properties; are you actually handling the Repeater.ItemCommand event?

如果是，如果您的页面调用控件的填写方法在回发，这将解释它。

If so, and if your page calls the control's Fill method on postbacks, that would explain it.

这些经典的ASP.NET发型问题在这些帖子中解释： ASP.NET问题的破坏者和 ASP.NET问题的修补程序问题：SOLVED！

This classic ASP.NET hair-tearing problem is explained in these posts: A Stumper of an ASP.NET Question and A Stumper of an ASP.NET Question: SOLVED!

这个解释是有点心灵的，但它的关键是 Repeater.DataBind 会干扰ASP.NET的能力以确定哪个中继器按钮导致回发。

The explanation is a little mind-bending, but the crux of it is that Repeater.DataBind interferes with ASP.NET's ability to determine which repeater button caused a postback.

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