Check Facebook Login in Android
<p>I have an application that uses the Facebook SDK for Android to login into my application. But I am having some problems in checking whether the user is already logged-in or not. After the login page, the main interface will be displayed to the user. What I want is that, if the user  has logged-in in its past interaction with application, the next time the application is launched, no more login screen just the main interface. So at start-up my application should check whether a user is logged in or not. How will I do it? </p>

<p>I tried using <code>mFacebook.isSessionValid()</code>, but it's always returning a false.</p>
