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

请在这里检查我的答案。基本上我只需要:

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

不要在saveInstanceState方法上调用super()。这把事情搞砸了……

这是支持包中的一个已知错误。

如果你需要保存实例并添加一些东西到outState Bundle中,你可以使用以下方法:

@Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putString("WORKAROUND_FOR_BUG_19917_KEY", "WORKAROUND_FOR_BUG_19917_VALUE");
    super.onSaveInstanceState(outState);
}

最后,正确的解决方案是(如评论所示)使用:

transaction.commitAllowingStateLoss();

当添加或执行导致异常的FragmentTransaction时。

其他回答

如果状态保存,请使用remove()而不是popup()。

   private void removeFragment() {
    FragmentManager fragmentManager = getSupportFragmentManager();
    if (fragmentManager.isStateSaved()) {
        List<Fragment> fragments = fragmentManager.getFragments();
        if (fragments != null && !fragments.isEmpty()) {
            fragmentManager.beginTransaction().remove(fragments.get(fragments.size() - 1)).commitAllowingStateLoss();
        }
    }
}

另一个可能的解决方法,我不确定是否在所有情况下都有帮助(来源在这里):

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        final View rootView = findViewById(android.R.id.content);
        if (rootView != null) {
            rootView.cancelPendingInputEvents();
        }
    }
}

Fragment事务不应该在Activity.onStop()之后执行! 检查你没有任何回调可以在onStop()之后执行事务。最好是修复原因,而不是尝试使用.commitAllowingStateLoss()等方法来绕过问题。

每当你试图在你的活动中加载一个片段时,请确保活动处于恢复状态,而不是进入暂停状态。在暂停状态下,您可能会丢失已完成的提交操作。

你可以使用transaction.commitAllowingStateLoss()而不是transaction.commit()来加载片段

or

创建一个布尔值并检查activity是否不进入onpause状态

@Override
public void onResume() {
    super.onResume();
    mIsResumed = true;
}

@Override
public void onPause() {
    mIsResumed = false;
    super.onPause();
}

然后在加载片段时检查

if(mIsResumed){
//load the your fragment
}

从支持库版本24.0.0开始,您可以调用FragmentTransaction.commitNow()方法,该方法同步提交事务,而不是调用commit(),然后调用executePendingTransactions()。正如文档所述,这种方法甚至更好:

调用commitNow比调用commit()之后再调用executePendingTransactions()更可取,因为后者会产生试图提交所有当前挂起的事务的副作用,无论这是否是所需的行为。