UserControl中的LinkButton返回,但不触发OnClick

我有一个名为RolloverLink的用户控件,它基本上包含 asp:LinkButton 和一个 <img /> . 我尝试如下设置onclick处理程序:

<%@ Control Language="C#" AutoEventWireup="true" 
    CodeBehind="RolloverLink.ascx.cs" Inherits="Controls.RolloverLink" %>
<asp:LinkButton  runat="server" ID="mug" OnClick="propagate" 
    CausesValidation="false" onmouseout="MM_swapImgRestore()" >
       <img runat="server" ID="pug" name="<%# pug.ClientID %>" border="0" />
</asp:LinkButton>

我在 propagate 方法,但它不会就此停止。页面会回发(闪烁),但不会调用事件。

下面是我的代码隐藏方式:

public partial class RolloverLink : System.Web.UI.UserControl
{
    private string _imageRl;
    public string Href { get; set; }
    public string ImageUp { get { return pug.Src; } set { pug.Src = value; } }
    public string ImageRl {
        get
        { 
            return _imageRl;
        }
        set
        {
            _imageRl = value;
            mug.Attributes["onmouseover"] = "MM_swapImage('"+pug.ClientID+"','','"+_imageRl+"',1)";
        }
    }
    public string Alt { get { return pug.Alt; } set { pug.Alt = value; } }
    public int Width { get { return pug.Width; } set { pug.Width = value; } }
    public int Height { get { return pug.Height; } set { pug.Height = value; } }
    public event EventHandler Click
    {
        add{click += value; }
        remove { click -= value; }
    }
    private event EventHandler click;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.Url.AbsolutePath.EndsWith(Href))
            ImageUp = ImageRl;
    }
    protected void propagate(object sender, EventArgs e)
    {
        EventHandler copy = click;
        if (copy != null)
            copy(this, EventArgs.Empty);
        else
            Response.Redirect(Href);
    }
}

这就是我在主页上使用它的方式:

<pwc:RolloverLink ID="contacts" Href="Contacts.aspx" 
    ImageRl="images/M_contacts_rl.png" ImageUp="images/M_contacts_up.png" 
    Alt="Initech Global : Laurierville, Qu&eacute;bec, Canada" Width="61" 
    Height="17" runat="server" />

是否有人有想法或指向想法的指针?