SharedPreferences返回一個空字符串

Question

為什么烤面包只顯示一個空字符串或我在getString行上輸入的“默認”值

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

    SharedPreferences sharedPreferences = this.getSharedPreferences("com.example.stefan.dijeljenepreference", Context.MODE_PRIVATE);
    sharedPreferences.edit().putString("username", "stefan");

    String username = sharedPreferences.getString("username","");
    Toast.makeText(this,"username:" + username, Toast.LENGTH_SHORT).show();
}

Answer 1

您應該使用如下的apply（）方法保存所做的編輯

sharedPreferences.edit().putString("username", "stefan").apply();