android facebook login button does not work - facebook

Question

I'm following this tutorial "Facebook Login Flow for Android" (https://developers.facebook.com/docs/howtos/androidsdk/3.0/login-with-facebook/) to create a simple app containing only one facebook login button to test facebook login.
However, I've been having trouble logging in facebook with this button.... I've been following every step in this tutorial and I've double checked everything -- it is exactly the same as in this tutorial. I see other people who have similar problems are always because of incorrect debug hash code. But I've checked like a million times that I got the correct debug hash code. Some people say that if you wanna release an app, you need a release code. However, I'm not releasing my app -- I'm just testing it on an android device, so I guess I dont really need a release code to do that?
Also, I've checked that I've included my facebook application id for this app in the Android Manifest. So basically, everything I did was strictly following the tutorials on Facebook Developers.
I've seen some people suggesting to use the "keytool" in JDK 6 in stead of JDK 7. And I've checked that I actually did generate my debug hash code with the "keytool" in JDK 6.
So I've tried everything, but the problem still exists!
In that Android Tutorial, it suggests putting this in your code so that you can monitor your LogCat to see if your current state is logged in or logged out:
private void onSessionStateChange(Session session, SessionState state, Exception exception) {
if (state.isOpened()) {
Log.i(TAG, "Logged in...");
} else if (state.isClosed()) {
Log.i(TAG, "Logged out...");
}
}
In my case, no matter how many times I clicked Facebook Login Button, I always got "Logged out..." in my LogCat.
Also, the funny thing is, I can't even log in facebook using those sample apps coming with Facebook Android SDK 3.0.1 (eg. SessonLoginSample)!!!!! When I click the login button in those sample apps, nothing happens -- which means I'm not successfully logged in.
I really hope you guys out there can help me with this problem. It's weird I don't see other people with the exact same problem (as I said, those with similar problems are always because of incorrect debug code, but I've checked mine, it is 100% correct). THANK YOU SO MUCH!

Answer 1

It happened to me once. You might have added the export key hash in facebook developer setting.
Add these lines to your code to get your debugging key hash and then add to facebook.
for (Signature signature : info.signatures) {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(signature.toByteArray());
Log.d("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
}