How to edit CSS style of a div using C# in .NET

Question

I'm trying to grab a div's ID in the code behind (C#) and set some css on it. Can I grab it from the DOM or do I have to use some kind of control?

<div id="formSpinner">     <img src="images/spinner.gif" />     <p>Saving...</p> </div> 

Answer 1

Add the runat="server" attribute to it so you have:

<div id="formSpinner" runat="server">     <img src="images/spinner.gif">     <p>Saving...</p> </div> 

That way you can access the class attribute by using:

formSpinner.Attributes["class"] = "classOfYourChoice"; 

It's also worth mentioning that the asp:Panel control is virtually synonymous (at least as far as rendered markup is concerned) with div, so you could also do:

<asp:Panel id="formSpinner" runat="server">     <img src="images/spinner.gif">     <p>Saving...</p> </asp:Panel> 

Which then enables you to write:

formSpinner.CssClass = "classOfYourChoice"; 

This gives you more defined access to the property and there are others that may, or may not, be of use to you.

Answer 2

Make sure that your div is set to runat="server", then simply reference it in the code-behind and set the "class" attribute.

<div runat="server" id="formSpinner">    ...content... </div> 

Code-behind

formSpinner.Attributes["class"] = "class-name";