<p>I want to get a type of a "BasePage" object that I am creating. Every Page object is based off BasePage. For instance, I have a Login.aspx and in my code-behind and a class that has a method Display:</p>

<pre><code>Display(BasePage page) {
    ResourceManager manager = new ResourceManager(page.GetType());
}
</code></pre>

<p>In my project structure I have a default resource file and a psuedo-translation resource file. If I set try something like this:</p>

<pre><code>Display(BasePage page) {
    ResourceManager manager = new ResourceManager(typeof(Login));
}
</code></pre>

<p>it returns the translated page.  After some research I found that page.GetType().ToString() returned something to the effect of "ASP_login.aspx" How can I get the actual code behind class type, such that I get an object of type "Login" that is derived from "BasePage"? </p>

<p>Thanks in advance!</p>

It depends where you're calling Display() from. If you're calling it from the ASPX, then you'llse "ASP_login.aspx". If you're calling it from the code-behind (i.e. the Page_Load() method) you should get the Login page type.
Instead of passing the Page in, you might consider just using the Page property (i.e. this.Page.GetType()) which should always be the current page/codebehind type, if I recall correctly.
I should also make the point that you might consider moving this sort of stuff out of the ASPX/codebehind and into some sort of service. It's generally a good idea to minimize the amount of things you do in a code behind and, instead, push logic into a presenter class and follow the MVP pattern for ASP.NET Web Forms development.