带动画的ModalPopUpExtender标记

Question

我有一个问题，我在我的网页中创建了一个ModelPopUpExtender控件。它运行正常，没有动画标签，但当我添加了一个动画标签时，它返回错误为“TargetControlID动画=”Button2“使用属性AjaxControlToolkit.ModalPopupExtender.OnShowing不存在或不能设置”

我不知道为什么它返回这种类型的错误？请给我建议任何解决方案。

在此先感谢。

代码：

<asp:ModalPopupExtender ID="ModalPopupExtender2" runat="server" TargetControlID="Button2" CancelControlID="Button4" PopupDragHandleControlID="Panel2" DropShadow="true"> 
     <Animations> 
       <OnShowing> 
       <FadeIn Duration=".5" Fps="30" /> 
      </OnShowing> 
      <OnShown> 
       <FadeIn Duration=".5" Fps="30" /> 
      </OnShown> 
      <%-- neither animation works from code-behind --%> 
      <OnHiding> 
       <FadeOut Duration=".5" Fps="30" /> 
      </OnHiding> 
      <OnHidden> 
       <FadeOut Duration=".5" Fps="30" /> 
      </OnHidden> 

      </Animations> 
     </asp:ModalPopupExtender> 

Answer 1

<Animations> 
<OnShown><Fadein Duration="0.50" /></OnShown> 
     <OnHiding><Fadeout Duration="0.75" /></OnHiding> 
</Animations> 

Answer 2

<asp:ModalPopupExtender runat="server" ID="ModalPopupExtender2" TargetControlID="Button2" 
          PopupControlID="Panel2" 
          DropShadow="true" 
          BackgroundCssClass="modalBackground" 
          CancelControlID="Button4"> 

<Animations> 
<OnShown><Fadein Duration="0.50" /></OnShown> 
<OnHiding><Fadeout Duration=".05" /></OnHiding> 
</Animations> 
</asp:ModalPopupExtender> 

<asp:Panel runat="server" ID="PnlDesignation" ScrollBars="Auto" CssClass="loginpnl" style="display:none"> 

    <div class="closepop text-right" id="Button4" > </div> 

</asp:Panel> 

CSS

.modalBackground 
{ 
background-color: #000; 
filter: alpha(opacity=70); 
opacity: 0.70; 
} 

.closepop 
{ 
margin:0 0 0 20px; 
BACKGROUND: url(../images/close.png) no-repeat 0 0; 
WIDTH:26px;POSITION: relative; background-position:right; 
HEIGHT: 26px; 
cursor:pointer; 
z-index: 100000; 
float:right; 
}