使用Firebase将完整侦听器添加到活动中的自定义登录

dependencies {
    // Firebase Authentication
    implementation 'com.google.firebase:firebase-auth:21.0.1'
}

private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mAuth = FirebaseAuth.getInstance();
    mAuthListener = new FirebaseAuth.AuthStateListener() {
        @Override
        public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
            FirebaseUser user = firebaseAuth.getCurrentUser();
            if (user != null) {
                // 用户已登录
                // 在这里处理登录后的逻辑
            } else {
                // 用户未登录
                // 在这里处理未登录时的逻辑
            }
        }
    };
}

@Override
protected void onStart() {
    super.onStart();
    mAuth.addAuthStateListener(mAuthListener);
}

@Override
protected void onStop() {
    super.onStop();
    if (mAuthListener != null) {
        mAuth.removeAuthStateListener(mAuthListener);
    }
}