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

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。

其他回答

你可以使用FragmentActivity。onStart在popBackStackImmediate之前

是这样的:

public void backStackFragment() {
    this.start();
    getFragmentManager().popBackStackImmediate();
}

public void start(){
    FragmentActivity a = getActivity();
    if(a instanceof DepositPlanPadActivity){
      ((DepositPlanPadActivity)a).onStart();
    }
    if(a instanceof SmallChangePlanPad){
            ((SmallChangePlanPad)a).onStart();
        }
        if(a instanceof UserCenterActivity){
            ((UserCenterActivity)a).onStart();
        }
    }

http://jorryliu.blogspot.com/2014/09/illegalstateexception-can-not-perform.html

我对这个问题的解决方案是

在片段中添加方法:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    ...
    guideMapFragment = (SupportMapFragment)a.getSupportFragmentManager().findFragmentById(R.id.guideMap);
    guideMap = guideMapFragment.getMap();
    ...
}

@Override
public void onDestroyView() {
    SherlockFragmentActivity a = getSherlockActivity();
    if (a != null && guideMapFragment != null) {
        try {
            Log.i(LOGTAG, "Removing map fragment");
            a.getSupportFragmentManager().beginTransaction().remove(guideMapFragment).commit();
            guideMapFragment = null;
        } catch(IllegalStateException e) {
            Log.i(LOGTAG, "IllegalStateException on exit");
        }
    }
    super.onDestroyView();
}

可能很糟糕,但找不到更好的了。

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();
    }
}

你可能会调用fragmentManager.popBackStackImmediate();当活动暂停时。活动未完成,但处于暂停状态,且不在前台。你需要在popBackStackImmediate()之前检查activity是否被暂停。

在屏幕被锁定\blank并且Activity +对话框的实例状态被保存之后,在对话框片段上调用dismiss()也会发生这种情况。要绕过这个调用:

dismissAllowingStateLoss()

实际上,每次我解散一个对话框时,我都不再关心它的状态了,所以这样做是可以的——实际上你并没有失去任何状态。