Picking One Animation Out Of a List

Christian Wenz

Overview

The Animation control in the ASP.NET AJAX Control Toolkit is not just a control but a whole framework to add animations to a control. The framework also allows the programmer to pick one animation out of a list of animations, depending on the evaluation of some JavaScript code.

Steps

First of all, include the ScriptManager in the page; then, the ASP.NET AJAX library is loaded, making it possible to use the Control Toolkit:

<asp:ScriptManager ID="asm" runat="server" />

The animation will be applied to a panel of text which looks like this:

<asp:Panel ID="panelShadow" runat="server" CssClass="panelClass">      ASP.NET AJAX is a free framework for quickly creating a new generation of more      efficient, more interactive and highly-personalized Web experiences that work      across all the most popular browsers.<br />      ASP.NET AJAX is a free framework for quickly creating a new generation of more      efficient, more interactive and highly-personalized Web experiences that work      across all the most popular browsers.<br />      ASP.NET AJAX is a free framework for quickly creating a new generation of more      efficient, more interactive and highly-personalized Web experiences that work      across all the most popular browsers.<br /> </asp:Panel>

In the associated CSS class for the panel, define a nice background color and also set a fixed width for the panel:

<style type="text/css">      .panelClass {background-color: lime; width: 300px;} </style>

Then, add the AnimationExtender to the page, providing an ID, the TargetControlID attribute and the obligatory runat="server":

<ajaxToolkit:AnimationExtender ID="ae" runat="server" TargetControlID="Panel1">

Within the <Animations> node, use <OnLoad> to run the animations once the page has been fully loaded. Instead of one of the regular animations, the <Case> element comes into play. The value of its SelectScript attribute is evaluated; the return value must be numerical. Depending on this number, one of the subanimations within <Case> is executed. For instance, if SelectScript evaluates to 2, the Control Toolkit runs the third animation within <Case> (counting starts at 0).

The following markup defines three subanimations: Resizing the width, resizing the height, and fading out. The JavaScript code (Math.floor(3 * Math.random())) then picks a number between 0 and 2, so that one of the three animations is run:

<ajaxToolkit:AnimationExtender ID="ae" runat="server"      TargetControlID="Panel1">      <Animations>           <OnLoad>                <Case SelectScript="Math.floor(3 * Math.random())">                     <Resize Width="1000" Unit="px" />                     <Resize Height="150" Unit="px" />                     <FadeOut Duration="1.5" Fps="24" />                </Case>           </OnLoad>      </Animations> </ajaxToolkit:AnimationExtender>

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