Android-如何将Firebase Uid保存到SharedReferences？

在用户登录并获取其uid后，如何将其uid保存到SharedReferences上，以便在整个项目中访问它？ 这是我获取其uid的代码：

FirebaseAuth auth = FirebaseAuth.getInstance();
FirebaseAuth.AuthStateListener authListener = new FirebaseAuth.AuthStateListener() {
    @Override
    public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
        FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
        if (firebaseUser != null) {
            String userId = firebaseUser.getUid();
            String userEmail = firebaseUser.getEmail();
        } 
    }
};

---

像这样试试

private SharedPreferences sharedPref;
FirebaseAuth auth = FirebaseAuth.getInstance();
FirebaseAuth.AuthStateListener authListener = new FirebaseAuth.AuthStateListener() {
    @Override
    public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
        FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
        if (firebaseUser != null) {
            String userId = firebaseUser.getUid();
            String userEmail = firebaseUser.getEmail();
            sharedPref = getPreferences(MODE_PRIVATE);
            SharedPreferences.Editor editor = sharedPref.edit();
            editor.putString("firebasekey", userId);
            editor.commit();
        } 
    }
};

---

使用此代码将UID保存到

SharedReference

中

// for saving uid for shared preference



FirebaseAuth auth = FirebaseAuth.getInstance();
FirebaseAuth.AuthStateListener authListener = new FirebaseAuth.AuthStateListener() {
    @Override
    public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
        FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
        if (firebaseUser != null) {
            String userId = firebaseUser.getUid();
            String userEmail = firebaseUser.getEmail();
            SharedPreferences sp = getSharedPreferences(PREFS_UID ,Context.MODE_PRIVATE);
            sp.edit().putInt(Save_UID,userId ).commit();
        } 
    }
};


// Retrieving id to any activity by calling this

SharedPreferences sp = getSharedPreferences(PREFS_UID,Context.MODE_PRIVATE);
int sc  = sp.getInt(Save_UID,0); 

像这样尝试：

在其他活动中检索：

        sharedPref = getPreferences(MODE_PRIVATE);
        String UserId = sharedPref.getString("firebasekey", "");

---

“firebasekey”后面的“”代表什么？它是字符串类型的默认值@MozySo我应该把什么值放在那里？它就像“键”，“值”。您可以输入任何值。我输入了值“0”，但当我引用UserId并将该文件保存到Firebase时，该文件不是UserId而是“0”？

        sharedPref = getPreferences(MODE_PRIVATE);
        String UserId = sharedPref.getString("firebasekey", "");