Question

所以我的应用是这样的： mainActivity - ＆GT; gameview＆GT; gamegeneration

mainActivity会将信息（上下文，属性）传递到gameview，这会将gridColRow金额传递给gamegeneration（生成随机网格），然后会显示gameview。

但是，如果我更改了屏幕方向，则会创建一个新网格，即使屏幕方向发生变化，如何保持相同的网格呢？

我在游戏视图中使用它，

protected Parcelable onSaveInstanceState() {}

和

protected void onRestoreInstanceState(Parcelable state) {}

＆安培;捆绑放置/恢复。

然而它不起作用，网格仍然不同。下面是一个简单的例子（我只想存储一个数字，但仍有问题）。

感谢

protected Parcelable onSaveInstanceState() {
        Bundle bd = new Bundle();
        bd.putParcelable("instanceState", super.onSaveInstanceState());
        bd.putInt("save1", numbersave);
        return super.onSaveInstanceState();

    }

protected void onRestoreInstanceState(Parcelable state) {
        Bundle bd = (Bundle) state;
        super.onRestoreInstanceState(bd.getParcelable("instanceState"));
        numbersave= bundle.getInt("save1");
    }

Answer 1

您需要覆盖onSaveInstanceState(Bundle savedInstanceState)并将要更改的应用程序状态值写入Bundle参数，如下所示：

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
  super.onSaveInstanceState(savedInstanceState);
  // Save UI state changes to the savedInstanceState.
  // This bundle will be passed to onCreate if the process is
  // killed and restarted.
  savedInstanceState.putBoolean("MyBoolean", true);
  savedInstanceState.putDouble("myDouble", 1.9);
  savedInstanceState.putInt("MyInt", 1);
  savedInstanceState.putString("MyString", "Welcome back to Android");
  // etc.
  // Also you can add parcelable and serializable for Objects of classes
}

Bundle本质上是一种存储NVP（“名称 - 价值对”）地图的方式，它将被传递到onCreate()，即你可以在onCraete恢复你的状态

    // Check whether we're recreating a previously destroyed instance
    if (savedInstanceState != null) {
        // Restore UI state from the savedInstanceState.
        // This bundle has also been passed to onCreate.
        boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
        double myDouble = savedInstanceState.getDouble("myDouble");
        int myInt = savedInstanceState.getInt("MyInt");
        String myString = savedInstanceState.getString("MyString");
        // etc.
        // Also you can get parcelable and serializable for Objects of classes
    } else {
        // Probably initialize members with default values for a new instance
    }

或你可以覆盖onRestoreInstanceState()，你可以在这里提取这样的值：

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
  super.onRestoreInstanceState(savedInstanceState);
  // Restore UI state from the savedInstanceState.
  // This bundle has also been passed to onCreate.
  boolean myBoolean = savedInstanceState.getBoolean("MyBoolean");
  double myDouble = savedInstanceState.getDouble("myDouble");
  int myInt = savedInstanceState.getInt("MyInt");
  String myString = savedInstanceState.getString("MyString");
  // etc.
  // Also you can get parcelable and serializable for Objects of classes
}

您通常会使用此技术来存储应用程序的实例值（选择，未保存的文本等）。

修改：

要保存班级Gameview对象的状态，班级必须实施parcelable（推荐）或serializable，详情请见answer

如何保存视图类？

1 个答案: