我有一个Live Android应用程序,从市场上我收到了以下堆栈跟踪,我不知道为什么它会发生,因为它不是发生在应用程序代码中,而是由应用程序的一些或其他事件引起的(假设)

我没有使用片段,仍然有一个FragmentManager的参考。 如果有人能揭示一些隐藏的事实,以避免这类问题:

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.onKeyDown(Activity.java:1962)
at android.view.KeyEvent.dispatch(KeyEvent.java:2482)
at android.app.Activity.dispatchKeyEvent(Activity.java:2274)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1668)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1720)
at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1258)
at android.app.Activity.dispatchKeyEvent(Activity.java:2269)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1668)
at android.view.ViewRoot.deliverKeyEventPostIme(ViewRoot.java:2851)
at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2824)
at android.view.ViewRoot.handleMessage(ViewRoot.java:2011)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:132)
at android.app.ActivityThread.main(ActivityThread.java:4025)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
at dalvik.system.NativeStart.main(Native Method)  

当前回答

I noticed something very interesting. I have in my app the option to open the phone's gallery and the device asks what app to use, there I click on the gray area away from the dialog and saw this issue. I noticed how my activity goes from onPause, onSaveInstanceState back to onResume, it doesn't happen to visit onCreateView. I am doing transactions at onResume. So what I ended up doing is setting a flag being negated onPause, but being true onCreateView. if the flag is true onResume then do onCommit, otherwise commitAllowingStateLoss. I could go on and waste so much time but I wanted to check the lifecycle. I have a device which is sdkversion 23, and I don't get this issue, but I have another one which is 21, and there I see it.

其他回答

谢谢@gunar,但我认为有更好的方法。

医生说:

*如果您提交的单个事务没有修改 *碎片回栈,强烈考虑使用 * {@link FragmentTransaction#commitNow()}代替。这有助于避免 *当应用程序中的其他代码未提交时,会产生不必要的副作用 *需要不同时间的事务。 * * @return如果有任何待处理事务则返回true *执行。 * / executePendingTransactions();

所以使用commitNow替换:

fragmentTransaction.commit();
FragmentManager.executePendingTransactions()

这发生在你试图加载一个片段,但活动已改变其状态为onPause()。例如,当您试图获取数据并将其加载到活动中,但当用户单击某个按钮并移动到下一个活动时,就会发生这种情况。

你可以用两种方法解决这个问题

您可以使用transaction.commitAllowingStateLoss()而不是transaction.commit()来加载片段,但您可能最终会丢失已完成的提交操作。

or

在加载片段时,确保活动处于恢复状态,而不是进入暂停状态。 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,而加载片段检查活动是否存在,只有当活动是前景时才加载。

if(mIsResumed){
 //load the fragment
}

这对我很管用……我自己发现的…希望对你有所帮助!

1)不要有全局的“静态”FragmentManager / FragmentTransaction。

2) onCreate,总是初始化FragmentManager再次!

样本如下:-

public abstract class FragmentController extends AnotherActivity{
protected FragmentManager fragmentManager;
protected FragmentTransaction fragmentTransaction;
protected Bundle mSavedInstanceState;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mSavedInstanceState = savedInstanceState;
    setDefaultFragments();
}

protected void setDefaultFragments() {
    fragmentManager = getSupportFragmentManager();
    //check if on orientation change.. do not re-add fragments!
    if(mSavedInstanceState == null) {
        //instantiate the fragment manager

        fragmentTransaction = fragmentManager.beginTransaction();

        //the navigation fragments
        NavigationFragment navFrag = new NavigationFragment();
        ToolbarFragment toolFrag = new ToolbarFragment();

        fragmentTransaction.add(R.id.NavLayout, navFrag, "NavFrag");
        fragmentTransaction.add(R.id.ToolbarLayout, toolFrag, "ToolFrag");
        fragmentTransaction.commitAllowingStateLoss();

        //add own fragment to the nav (abstract method)
        setOwnFragment();
    }
}

读 http://chris-alexander.co.uk/on-engineering/dev/android-fragments-within-fragments/

篇文章。 fragment. isresume()检查帮助我在onDestroyView w/o使用onSaveInstanceState方法。

我发现,如果另一个应用程序是对话类型,并允许触摸被发送到后台应用程序,那么几乎任何后台应用程序都会崩溃与此错误。 我认为我们需要在每次执行事务时检查实例是否保存或恢复。