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

为了补充其他答案-如果您有多个具有相同ID的自定义复合视图，并且它们都在配置更改时使用上一个视图的状态进行恢复，您所需要做的就是告诉视图仅通过覆盖两个方法将保存/恢复事件分派给自己。

class MyCompoundView : ViewGroup {

    ...

    override fun dispatchSaveInstanceState(container: SparseArray<Parcelable>) {
        dispatchFreezeSelfOnly(container)
    }

    override fun dispatchRestoreInstanceState(container: SparseArray<Parcelable>) {
        dispatchThawSelfOnly(container)
    }
}

对于正在发生的事情和为什么这样做的解释，请参阅这篇博客文章。基本上你的复合视图的子视图id是由每个复合视图共享的，状态恢复会很混乱。通过仅为复合视图本身调度状态，我们可以防止它们的子视图从其他复合视图获得混合消息。

这里的答案已经很好了，但并不一定适用于自定义viewgroup。为了让所有自定义视图保留它们的状态，你必须在每个类中重写onSaveInstanceState()和onRestoreInstanceState(Parcelable state)。 您还需要确保它们都具有唯一的id，无论它们是从xml扩展的还是以编程方式添加的。

我想出的答案与Kobor42的答案非常相似，但错误仍然存在，因为我以编程方式将视图添加到自定义ViewGroup中，而没有分配唯一的id。

由mato共享的链接可以工作，但这意味着没有任何单个视图管理它们自己的状态——整个状态保存在ViewGroup方法中。

问题是，当多个viewgroup被添加到一个布局中时，它们在xml中的元素id不再是唯一的(如果它是在xml中定义的)。在运行时，你可以调用静态方法View. generateviewid()来获取一个视图的唯一id。这只在API 17中可用。

下面是我在ViewGroup中的代码(它是抽象的，mOriginalValue是一个类型变量):

public abstract class DetailRow<E> extends LinearLayout {

    private static final String SUPER_INSTANCE_STATE = "saved_instance_state_parcelable";
    private static final String STATE_VIEW_IDS = "state_view_ids";
    private static final String STATE_ORIGINAL_VALUE = "state_original_value";

    private E mOriginalValue;
    private int[] mViewIds;

// ...

    @Override
    protected Parcelable onSaveInstanceState() {

        // Create a bundle to put super parcelable in
        Bundle bundle = new Bundle();
        bundle.putParcelable(SUPER_INSTANCE_STATE, super.onSaveInstanceState());
        // Use abstract method to put mOriginalValue in the bundle;
        putValueInTheBundle(mOriginalValue, bundle, STATE_ORIGINAL_VALUE);
        // Store mViewIds in the bundle - initialize if necessary.
        if (mViewIds == null) {
            // We need as many ids as child views
            mViewIds = new int[getChildCount()];
            for (int i = 0; i < mViewIds.length; i++) {
                // generate a unique id for each view
                mViewIds[i] = View.generateViewId();
                // assign the id to the view at the same index
                getChildAt(i).setId(mViewIds[i]);
            }
        }
        bundle.putIntArray(STATE_VIEW_IDS, mViewIds);
        // return the bundle
        return bundle;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {

        // We know state is a Bundle:
        Bundle bundle = (Bundle) state;
        // Get mViewIds out of the bundle
        mViewIds = bundle.getIntArray(STATE_VIEW_IDS);
        // For each id, assign to the view of same index
        if (mViewIds != null) {
            for (int i = 0; i < mViewIds.length; i++) {
                getChildAt(i).setId(mViewIds[i]);
            }
        }
        // Get mOriginalValue out of the bundle
        mOriginalValue = getValueBackOutOfTheBundle(bundle, STATE_ORIGINAL_VALUE);
        // get super parcelable back out of the bundle and pass it to
        // super.onRestoreInstanceState(Parcelable)
        state = bundle.getParcelable(SUPER_INSTANCE_STATE);
        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

用kotlin很容易

@Parcelize
class MyState(val superSavedState: Parcelable?, val loading: Boolean) : View.BaseSavedState(superSavedState), Parcelable


class MyView : View {

    var loading: Boolean = false

    override fun onSaveInstanceState(): Parcelable? {
        val superState = super.onSaveInstanceState()
        return MyState(superState, loading)
    }

    override fun onRestoreInstanceState(state: Parcelable?) {
        val myState = state as? MyState
        super.onRestoreInstanceState(myState?.superSaveState ?: state)

        loading = myState?.loading ?: false
        //redraw
    }
}

我发现这个答案在Android版本9和10上导致了一些崩溃。我认为这是一个很好的方法，但当我在看一些Android代码时，我发现它缺少一个构造函数。答案是相当古老的，所以在当时可能没有必要。当我添加了缺失的构造函数并从创建者调用它时，崩溃就修复了。

下面是编辑后的代码:

public class CustomView extends LinearLayout {

    private int stateToSave;

    ...

    @Override
    public Parcelable onSaveInstanceState() {
        Parcelable superState = super.onSaveInstanceState();
        SavedState ss = new SavedState(superState);

        // your custom state
        ss.stateToSave = this.stateToSave;

        return ss;
    }

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

    @Override
    public void onRestoreInstanceState(Parcelable state) {
        SavedState ss = (SavedState) state;
        super.onRestoreInstanceState(ss.getSuperState());

        // your custom state
        this.stateToSave = ss.stateToSave;
    }

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

    static class SavedState extends BaseSavedState {
        int stateToSave;

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

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

        // This was the missing constructor
        @RequiresApi(Build.VERSION_CODES.N)
        SavedState(Parcel in, ClassLoader loader)
        {
            super(in, loader);
            this.stateToSave = in.readInt();
        }

        @Override
        public void writeToParcel(Parcel out, int flags) {
            super.writeToParcel(out, flags);
            out.writeInt(this.stateToSave);
        }    
        
        public static final Creator<SavedState> CREATOR =
            new ClassLoaderCreator<SavedState>() {
          
            // This was also missing
            @Override
            public SavedState createFromParcel(Parcel in, ClassLoader loader)
            {
                return Build.VERSION.SDK_INT >= Build.VERSION_CODES.N ? new SavedState(in, loader) : new SavedState(in);
            }

            @Override
            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in, null);
            }

            @Override
            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }
}