带有动画标签的ModalPopUpExtender

Question

我有一个问题，我正在我的网页中创建一个ModelPopUpExtender控件。没有动画标签它运行正常，但当我在其中添加动画标签时，它返回错误，因为“在TargetControlID上的动画=”Button2“使用属性AjaxControlToolkit.ModalPopupExtender.OnShowing不存在或无法设置”

我不知道为什么它会返回这种类型的错误？请建议我任何有关相同的解决方案。

提前致谢。

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;
}