IllegalStateException:在ViewPager的onSaveInstanceState后不能执行此操作

我在市场上从我的应用程序获得用户报告，交付以下异常:

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1109)
at android.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:399)
at android.app.Activity.onBackPressed(Activity.java:2066)
at android.app.Activity.onKeyUp(Activity.java:2044)
at android.view.KeyEvent.dispatch(KeyEvent.java:2529)
at android.app.Activity.dispatchKeyEvent(Activity.java:2274)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1803)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1855)
at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1277)
at android.app.Activity.dispatchKeyEvent(Activity.java:2269)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1803)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.widget.TabHost.dispatchKeyEvent(TabHost.java:297)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1855)
at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1277)
at android.app.Activity.dispatchKeyEvent(Activity.java:2269)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1803)
at android.view.ViewRoot.deliverKeyEventPostIme(ViewRoot.java:2880)
at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2853)
at android.view.ViewRoot.handleMessage(ViewRoot.java:2028)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:132)
at android.app.ActivityThread.main(ActivityThread.java:4028)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
at dalvik.system.NativeStart.main(Native Method)

显然这与FragmentManager有关，而我并不使用它。堆栈跟踪没有显示任何我自己的类，所以我不知道这个异常发生在哪里以及如何防止它。

为了记录:我有一个tabhost，在每个选项卡中都有一个在活动之间切换的ActivityGroup。

当前回答

异常在这里抛出(在FragmentActivity中):

@Override
public void onBackPressed() {
    if (!mFragments.getSupportFragmentManager().popBackStackImmediate()) {
        super.onBackPressed();
    }
}

在FragmentManager.popBackStatckImmediate()中，FragmentManager.checkStateLoss()首先被调用。这就是IllegalStateException的原因。参见下面的实现:

private void checkStateLoss() {
    if (mStateSaved) { // Boom!
        throw new IllegalStateException(
                "Can not perform this action after onSaveInstanceState");
    }
    if (mNoTransactionsBecause != null) {
        throw new IllegalStateException(
                "Can not perform this action inside of " + mNoTransactionsBecause);
    }
}

我通过使用一个标志来标记Activity的当前状态来解决这个问题。以下是我的解决方案:

public class MainActivity extends AppCompatActivity {
    /**
     * A flag that marks whether current Activity has saved its instance state
     */
    private boolean mHasSaveInstanceState;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        mHasSaveInstanceState = true;
        super.onSaveInstanceState(outState);
    }

    @Override
    protected void onResume() {
        super.onResume();
        mHasSaveInstanceState = false;
    }

    @Override
    public void onBackPressed() {
        if (!mHasSaveInstanceState) {
            // avoid FragmentManager.checkStateLoss()'s throwing IllegalStateException
            super.onBackPressed();
        }
    }
}

2017-08-07 06:19:20

其他回答

注意，使用transaction.commitAllowingStateLoss()可能会给用户带来糟糕的体验。有关为什么会抛出这个异常的更多信息，请参阅这篇文章。

2015-11-13 15:29:08

在我的案例中，我发现的最流畅和最简单的解决方案可能是避免在响应活动结果时从堆栈中弹出有问题的片段。所以在onActivityResult()中改变这个调用:

popMyFragmentAndMoveOn();

new Handler(Looper.getMainLooper()).post(new Runnable() {
    public void run() {
        popMyFragmentAndMoveOn();
    }
}

对我有帮助。

2017-06-02 16:52:01

将getFragmentManager()更改为getChildFragmentManager()。不要使用父FragmentManager，尽量使用self。

2021-12-03 02:04:52

我知道@Ovidiu Latcu有一个公认的答案，但过了一段时间，错误仍然存在。

@Override
protected void onSaveInstanceState(Bundle outState) {
     //No call for super(). Bug on API Level > 11.
}

Crashlytics仍然给我发送这个奇怪的错误信息。

但是错误现在只发生在版本7+(牛轧糖) 我的修复方法是在fragmentTransaction中使用commitAllowingStateLoss()而不是commit()。

这篇文章对commitAllowingStateLoss()有帮助，并且再也没有片段问题了。

总而言之，这里公认的答案可能适用于牛轧糖之前的安卓版本。

这可能会节省一些人几个小时的搜索时间。幸福的准则。< 3干杯

2018-05-18 05:06:06

我也经历过这个问题，每当FragmentActivity的上下文发生变化时(例如屏幕方向被改变等)，问题就会发生。所以最好的修复方法就是从FragmentActivity中更新context。

2016-04-01 10:54:10

IllegalStateException:在ViewPager的onSaveInstanceState后不能执行此操作

推荐文章

最新文章

标签