java-使用Android Studio和Facebook SDK实现Facebook登录

Question

I've tried to use the Facebook SDK to create a simple Facebook login inside my application. Everything works fine, but the registerCallback function of LoginButton does not work properly. This is my code:

    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    FacebookSdk.sdkInitialize(getApplicationContext());
    callbackManager = CallbackManager.Factory.create();

    setContentView(R.layout.activity_main);
    loginButton = (LoginButton)findViewById(R.id.btn_login);

    loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            message = "Success! ";
        }

        @Override
        public void onCancel() {
            message = "Cancel!";
        }

        @Override
        public void onError(FacebookException e) {
            message = e.getMessage();
        }
    });
}

This is inside my main activity. I then proceed to print the 'message' variable which is always empty because none of the registerCallback functions seems to be executed. If I try to login again, Facebook says that I already enabled this application, but I did not receive feedback about the LoginResult.

Answer 1

Have you implemented onActivityResult in your activity

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    callbackManager.onActivityResult(requestCode, resultCode, data);
}