I am trying to make a really basic Facebook login program for Android studio. I have followed all of the steps, exactly as described in at least 4 tutorials, but the result remains the same. When I open the app it crashes. So here is my code:
private FacebookCallback<LoginResult> mCallBack = new FacebookCallback<LoginResult>(){
@Override
public void onSuccess(LoginResult loginResult) {
AccessToken accessToken = loginResult.getAccessToken();
Profile profile = Profile.getCurrentProfile();
if(profile!=null){
textlogin.setText("Hello "+profile.getFirstName());
}
}
@Override
public void onCancel() {
// App code
}
@Override
public void onError(FacebookException exception) {
// App code
}
};
@Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
FacebookSdk.sdkInitialize(getActivity().getApplicationContext());
callbackManager=CallbackManager.Factory.create();
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
LoginButton loginButton = (LoginButton)view.findViewById(R.id.login_button);
textlogin = (TextView)view.findViewById(R.id.textView);
loginButton.setReadPermissions("user_friends");
loginButton.setFragment(this);
loginButton.registerCallback(callbackManager, mCallBack);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode,resultCode,data);
callbackManager.onActivityResult(requestCode,resultCode,data);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_main, container, false);
}
and here is the error log (it really is that short):
java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:911)
at com.facebook.internal.Utility.queryAppSettings(Utility.java:802)
at com.facebook.login.widget.LoginButton$1.run(LoginButton.java:509)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Found error. Misplaced the <Metadata>
. All working now!
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.