Adding css class through aspx code behind
If you want to add attributes, including the class, you need to set runat="server" on the tag.
<div id="classMe" runat="server"></div>Then in the code-behind:
classMe.Attributes.Add("class", "some-class")
If you're not using the id for anything other than code-behind reference (since .net mangles the ids), you could use a panel control and reference it in your codebehind:
<asp:panel runat="server" id="classMe"></asp:panel>classMe.cssClass = "someClass"
Assuming your div has some CSS classes already...
<div id="classMe" CssClass="first"></div>The following won't replace existing definitions:
ClassMe.CssClass += " second";And if you are not sure until the very last moment...
string classes = ClassMe.CssClass;ClassMe.CssClass += (classes == "") ? "second" : " second";