Android - Firebase Dynamic Facebook button

问题

Excuse me for double posting this question, I did not get a response and I still have the same problem. Tried to fix it, but wasn't successful. Any help is greatly appreciated.

I want to use the Facebook login button to sign users in to my app.

Now when the loginbutton is clicked, I log in and continue to the 2nd activity.

callbackManager = CallbackManager.Factory.create();
    LoginButton loginButton = (LoginButton) findViewById(R.id.loginButton);
    loginButton.setReadPermissions("email", "public_profile");
    loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            Log.d(TAG, "facebook:onSuccess:" + loginResult);
            handleFacebookAccessToken(loginResult.getAccessToken());
        }

        @Override
        public void onCancel() {
            Log.d(TAG, "facebook:onCancel");
            // ...
        }

        @Override
        public void onError(FacebookException error) {
            Log.d(TAG, "facebook:onError", error);
            // ...
        }
    });

Now in the 2nd activity, I have a button Sign Out which returns me to the 1st activity, and sign out my account I signed in with. Code:

        AuthUI.getInstance()
                .signOut(this)
                .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        finish();
                    }
                });

Now, everything works fine, except for the sign out part.

It does sign out the account (I can see it in my log). But when I get back to the MainActivity, the dynamic Facebook login button still says: Sign out while it should already say Sign in with Facebook.

This is the Facebook button I use:

    <com.facebook.login.widget.LoginButton
    android:id="@+id/loginButton"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_gravity="center_horizontal"
    android:layout_weight="1"
    android:layout_marginBottom="56dp"
    android:layout_alignParentBottom="true"
    android:layout_alignParentStart="true" />

I have googled this, but I could not find anything. Tried to change the sign out method to

FirebaseAuth.getInstance().signOut();

But this was without any different result.

回答1:

I had the same bad experience with that. Finally, I use the LoginManager for Facebook authentication and did something like this:

public void logOut() {
    FirebaseAuth.getInstance().signOut();
    LoginManager.getInstance().logOut();
}

来源：https://stackoverflow.com/questions/40985007/android-firebase-dynamic-facebook-button