Question

我正在为java类构建一个内存游戏应用程序，我需要保存通过设备旋转显示哪些单词...需要保存并传递给新的onCreate（）方法的小部件是按钮小部件我使用setText显示正在显示的单词....我可以保存并传递应用程序的整个状态...这是我的代码显然不起作用，我希望我能得到一些见解..谢谢......这是我的代码..

private Bundle myBundle = new Bundle();
.....
@Override
protected void onCreate(Bundle savedInstanceState) {


    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_eight);

    if(savedInstanceState != null) {
        savedInstanceState = myBundle;
    }
    ......
    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
       super.onSaveInstanceState(savedInstanceState);
       myBundle = savedInstanceState;
}

Answer 1

你有向后使用Bundle的语义。你不想要保存Bundle（或覆盖它）。只需使用它将您自己的状态变量序列化到其中即可。例如，如果要在旋转之间保留两个整数变量和一个字符串（以便稍后可以使用这些成员重新初始化视图），则可以执行以下操作：

protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_eight);

    if(savedInstanceState != null) {

        // Restore our member variables that represent activity state right here from the passed in Bundle.

        _x = savedInstanceState.getInt("MyApp.X", 0);
        _y = savedInstanceState.getInt("MyApp.Y", 0);
        _name = savedInstanceState.getString("MyApp.NAME", "player");

        // not shown - initializing the view elements with the initialized member variables.

    }
......

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {

   // save our activity state by adding our member variables that represent activity state into the Bundle.
   savedInstanceState.putInt("MyApp.X", _x);
   savedInstanceState.putInt("MyApp.Y", _y);
   savedInstanceState.putString("MyApp.NAME", _name);

    // call the parent method *after* you have saved your state
   super.onSaveInstanceState(savedInstanceState);
}

Bundle还支持简单类型的数组。

Answer 2

在onSaveInstanceState方法中，添加要保存的值，如下所示

@Override
  public void onSaveInstanceState(Bundle savedInstanceState) {
   savedInstanceState.putString("key","your string here");
}

并在oncreate里面

@Override
public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  if( savedInstanceState != null ) {
     System.out.println(savedInstanceState .getString("key"));
  }

}

通过轮换保存我的应用程序的状态

2 个答案: