java - SharedPreferences 返回空字符串

Question

为什么 toast 只显示空字符串或我在 getString 行上输入的“默认”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

您应该使用这样的apply()方法保存您的编辑

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