除了使用onSaveInstanceState和onRestoreInstanceState，你还可以使用ViewModel。让你的数据模型扩展ViewModel，然后你可以在每次Activity被重新创建时使用ViewModelProviders来获得你的模型的相同实例:

class MyData extends ViewModel {
    // have all your properties with getters and setters here
}

public class MyActivity extends FragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // the first time, ViewModelProvider will create a new MyData
        // object. When the Activity is recreated (e.g. because the screen
        // is rotated), ViewModelProvider will give you the initial MyData
        // object back, without creating a new one, so all your property
        // values are retained from the previous view.
        myData = ViewModelProviders.of(this).get(MyData.class);

        ...
    }
}

要使用ViewModelProviders，在app/build.gradle中添加以下依赖项:

implementation "android.arch.lifecycle:extensions:1.1.1"
implementation "android.arch.lifecycle:viewmodel:1.1.1"

注意你的MyActivity扩展了FragmentActivity而不仅仅是扩展了Activity。

你可以在这里阅读更多关于ViewModels的信息:

Android开发者指南，处理配置更改 Android开发者指南，保存UI状态，使用ViewModel处理配置更改 教程视图模型:一个简单的例子

下面是另一种混合使用上述两种方法的变体。 将Parcelable的速度和正确性与Bundle的简单性结合起来:

@Override
public Parcelable onSaveInstanceState() {
    Bundle bundle = new Bundle();
    // The vars you want to save - in this instance a string and a boolean
    String someString = "something";
    boolean someBoolean = true;
    State state = new State(super.onSaveInstanceState(), someString, someBoolean);
    bundle.putParcelable(State.STATE, state);
    return bundle;
}

@Override
public void onRestoreInstanceState(Parcelable state) {
    if (state instanceof Bundle) {
        Bundle bundle = (Bundle) state;
        State customViewState = (State) bundle.getParcelable(State.STATE);
        // The vars you saved - do whatever you want with them
        String someString = customViewState.getText();
        boolean someBoolean = customViewState.isSomethingShowing());
        super.onRestoreInstanceState(customViewState.getSuperState());
        return;
    }
    // Stops a bug with the wrong state being passed to the super
    super.onRestoreInstanceState(BaseSavedState.EMPTY_STATE); 
}

protected static class State extends BaseSavedState {
    protected static final String STATE = "YourCustomView.STATE";

    private final String someText;
    private final boolean somethingShowing;

    public State(Parcelable superState, String someText, boolean somethingShowing) {
        super(superState);
        this.someText = someText;
        this.somethingShowing = somethingShowing;
    }

    public String getText(){
        return this.someText;
    }

    public boolean isSomethingShowing(){
        return this.somethingShowing;
    }
}

我认为这是一个更简单的版本。Bundle是实现Parcelable的内置类型

public class CustomView extends View
{
  private int stuff; // stuff

  @Override
  public Parcelable onSaveInstanceState()
  {
    Bundle bundle = new Bundle();
    bundle.putParcelable("superState", super.onSaveInstanceState());
    bundle.putInt("stuff", this.stuff); // ... save stuff 
    return bundle;
  }

  @Override
  public void onRestoreInstanceState(Parcelable state)
  {
    if (state instanceof Bundle) // implicit null check
    {
      Bundle bundle = (Bundle) state;
      this.stuff = bundle.getInt("stuff"); // ... load stuff
      state = bundle.getParcelable("superState");
    }
    super.onRestoreInstanceState(state);
  }
}

除了使用onSaveInstanceState和onRestoreInstanceState，你还可以使用ViewModel。让你的数据模型扩展ViewModel，然后你可以在每次Activity被重新创建时使用ViewModelProviders来获得你的模型的相同实例:

class MyData extends ViewModel {
    // have all your properties with getters and setters here
}

public class MyActivity extends FragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // the first time, ViewModelProvider will create a new MyData
        // object. When the Activity is recreated (e.g. because the screen
        // is rotated), ViewModelProvider will give you the initial MyData
        // object back, without creating a new one, so all your property
        // values are retained from the previous view.
        myData = ViewModelProviders.of(this).get(MyData.class);

        ...
    }
}

要使用ViewModelProviders，在app/build.gradle中添加以下依赖项:

implementation "android.arch.lifecycle:extensions:1.1.1"
implementation "android.arch.lifecycle:viewmodel:1.1.1"

注意你的MyActivity扩展了FragmentActivity而不仅仅是扩展了Activity。

你可以在这里阅读更多关于ViewModels的信息:

Android开发者指南，处理配置更改 Android开发者指南，保存UI状态，使用ViewModel处理配置更改 教程视图模型:一个简单的例子

我有一个问题，onRestoreInstanceState恢复了我所有的自定义视图与最后一个视图的状态。我通过向我的自定义视图添加这两个方法来解决这个问题:

@Override
protected void dispatchSaveInstanceState(SparseArray<Parcelable> container) {
    dispatchFreezeSelfOnly(container);
}

@Override
protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) {
    dispatchThawSelfOnly(container);
}

你可以通过实现view# onSaveInstanceState和view# onRestoreInstanceState并扩展视图来实现这一点。BaseSavedState类。

public class CustomView extends View {

  private int stateToSave;

  ...

  @Override
  public Parcelable onSaveInstanceState() {
    //begin boilerplate code that allows parent classes to save state
    Parcelable superState = super.onSaveInstanceState();

    SavedState ss = new SavedState(superState);
    //end

    ss.stateToSave = this.stateToSave;

    return ss;
  }

  @Override
  public void onRestoreInstanceState(Parcelable state) {
    //begin boilerplate code so parent classes can restore state
    if(!(state instanceof SavedState)) {
      super.onRestoreInstanceState(state);
      return;
    }

    SavedState ss = (SavedState)state;
    super.onRestoreInstanceState(ss.getSuperState());
    //end

    this.stateToSave = ss.stateToSave;
  }

  static class SavedState extends BaseSavedState {
    int stateToSave;

    SavedState(Parcelable superState) {
      super(superState);
    }

    private SavedState(Parcel in) {
      super(in);
      this.stateToSave = in.readInt();
    }

    @Override
    public void writeToParcel(Parcel out, int flags) {
      super.writeToParcel(out, flags);
      out.writeInt(this.stateToSave);
    }

    //required field that makes Parcelables from a Parcel
    public static final Parcelable.Creator<SavedState> CREATOR =
        new Parcelable.Creator<SavedState>() {
          public SavedState createFromParcel(Parcel in) {
            return new SavedState(in);
          }
          public SavedState[] newArray(int size) {
            return new SavedState[size];
          }
    };
  }
}

该工作在视图和视图的SavedState类之间进行分割。您应该在SavedState类中完成对Parcel进行读写的所有工作。然后，您的View类可以执行提取状态成员的工作，并执行将类恢复到有效状态所需的工作。

注意:如果View#getId返回值>= 0，则View#onSavedInstanceState和View#onRestoreInstanceState将自动为您调用。当您在xml中给它一个id或手动调用setId时，就会发生这种情况。否则，您必须调用view# onSaveInstanceState并将Parcelable返回到您在活动#onSaveInstanceState中获得的包中以保存状态，随后读取它并将其传递给活动#onRestoreInstanceState中的view# onRestoreInstanceState。

另一个简单的例子是CompoundButton