How do I dynamically add and remove a href

Try this:

ScriptManager.RegisterClientScriptBlock(this.Page, this.Page.GetType(), "script", "<script>$('#idLocal').append('<a href = \'url\'></a>');</script>", false);

Or this:

<asp:Button id="myid" runat="server" OnClientClick="$('#idLocal').append('<a href = \'url\'></a>')"/>

The code in js is using jQuery.

There are several ways. One of them, without changing the code a lot, is to add in a a runat="server" and a id='nome' .

 <a href="/UpLoads/<%# Eval("DsPathDocumento")%>" runat="server" class="linkUpload"><%#Eval("NmTipoDocumentoDown")%></a>

Then, in your .cs you will have to reference your nome like any other control.

Another way is to put an object of type HyperLink and set its Visible="false" . You can set your NavigateUrl (link) of your .cs . Only view the link when you need it.

By what looks like DsPathDocument is a string, so you can use something like:

I do not really like writing in ASP.NET using inline code, but since you're already using it, there's an alternative:

<% if(!String.IsNullOrEmpty(Eval("DsPathDocumento ").ToString())) { %>
    <a href="/UpLoads/<%# Eval("DsPathDocumento")%>" class="linkUpload"><%# Eval("NmTipoDocumentoDown")%></a>
<% } %>