You need to override DataBind() because the poll that is actually displayed is based on what the PollID is.
In some cases, the control is used like this:
Code:
<mb:PollBox id="PollBox1" runat="server" PollID='<%# Eval("ID") %>'
ShowHeader="False" ShowQuestion="False" ShowArchiveLink="False" />
In other cases, it is used like this:
Code:
<mb:PollBox id="PollBox1" runat="server"
ShowHeader="False" ShowQuestion="False" ShowArchiveLink="False" />
In the case where the PollID is specified declaratively, we need to show the specified Poll. In cases where no PollID is specified, we need to show the Current Poll.
In order to do that, you need to determine what the PollID is, and you do that by calling base.DataBind(); Then, you need to determine which poll to show based on the evaluated ID, which is done in the call to DoBinding().