androidandroid-fragmentsandroid-viewpagerillegalstateexceptionfragmenttransaction

Reputation: 100468

IllegalStateException: Can not perform this action after onSaveInstanceState with ViewPager

I'm getting user reports from my app in the market, delivering the following exception:

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)

Apparently it has something to do with a FragmentManager, which I don't use. The stacktrace doesn't show any of my own classes, so I have no idea where this exception occurs and how to prevent it.

For the record: I have a tabhost, and in each tab there is a ActivityGroup switching between Activities.

Upvotes: 579

Answers (30)

Abdul Muqeet

Reputation: 128

This error IllegalStateException: Can not perform this action after onSaveInstanceState occurs when you trying to create or replace a fragment while the parent activity or parent fragment is in a Stop State and UI doesn't exist.

Q. How can this state occur?.

A. When your parent activity or parent fragment is already in a stop state. This can happen when your app is trying to move to a new fragment while the user puts your app back to the background.

Q. Apparently it has something to do with a FragmentManager, which I don't use. The stacktrace doesn't show any of my own classes, so I have no idea where this exception occurs and how to prevent it

A. When you attach a ViewPager with Fragments. It internally uses FragmentManager to place fragments.

Q. How to handle it?

A. There are some solutions that others already give but I think you should not use a workaround to avoid this problem. It is a genuine problem and you should handle it gracefully.

You can use the below code to know whether the activity is in a stop state before placing fragments or attaching a viewpager

if(supportFragmentManager.isStateSaved.not()){
        // safe to attach viewpager or fragments
  }

Use childFragmentManager.isStateSaved if inside the parent fragment before placing fragments or attaching viewpager

Upvotes: 2

Lynda Douglas

Reputation: 11

I had the same problem but in my case, there were errors in my xml files. I added spaces between buttons and text boxes that were no longer allowed. When I removed them, I did not receive any report of this error.

Upvotes: 0

Njuacha Hubert

Reputation: 566

as you can see in your crash report, the last line that is throwing the exception is

checkStateLoss(FragmentManager.java:1109)

if you look at the implementation of checkStateLoss

private void checkStateLoss() {
    if (isStateSaved()) {
        throw new IllegalStateException(
                "Can not perform this action after onSaveInstanceState");
    }
}

so a simple solution for me is to find what ever method of the Fragment Manager you are calling in your app that eventually leads to this method being called and simply check if isStateSaved() is false before calling that method. For me it was the show() method. I did like this

if (!isStateSaved()) {
  myDialog.show(fragmentManager, Tag)
}

Upvotes: 4

user17576552

Reputation: 21

change getFragmentManager() to getChildFragmentManager(). Don't use parent FragmentManager, try to use self.

Upvotes: 2

CoolMind

Reputation: 28875

Kotlin extension

fun FragmentManager?.replaceAndAddToBackStack(
    @IdRes containerViewId: Int,
    fragment: () -> Fragment,
    tag: String
) {
    // Find and synchronously remove a fragment with the same tag.
    // The second transaction must start after the first has finished.
    this?.findFragmentByTag(tag)?.let {
        beginTransaction().remove(it).commitNow()
    }
    // Add a fragment.
    this?.beginTransaction()?.run {
        replace(containerViewId, fragment, tag)
        // The next line will add the fragment to a back stack.
        // Remove if not needed.
        // You can use null instead of tag, but tag is needed for popBackStack(), 
        // see https://stackoverflow.com/a/59158254/2914140
        addToBackStack(tag)
    }?.commitAllowingStateLoss()
}

Usage:

val fragment = { SomeFragment.newInstance(data) }
fragmentManager?.replaceAndAddToBackStack(R.id.container, fragment, SomeFragment.TAG)

Upvotes: 2

Ivo Stoyanov

Reputation: 18939

Fragment transactions should not be executed after Activity.onStop() ! Check that you do not have any callbacks that could execute transaction after onStop(). It is better to fix the reason instead of trying to walk around the problem with approaches like .commitAllowingStateLoss()

Upvotes: 5

Synesso

Reputation: 39018

There are many related problems with a similar error message. Check the second line of this particular stack trace. This exception is specifically related to the call to FragmentManagerImpl.popBackStackImmediate.

This method call, like popBackStack, will always fail with IllegalStateException if the session state has already been saved. Check the source. There is nothing you can do to stop this exception being thrown.

Removing the call to super.onSaveInstanceState will not help.
Creating the Fragment with commitAllowingStateLoss will not help.

Here's how I observed the problem:

There's a form with a submit button.
When the button is clicked a dialog is created and an async process starts.
The user clicks the home key before the process is finished - onSaveInstanceState is called.
The process completes, a callback is made and popBackStackImmediate is attempted.
IllegalStateException is thrown.

Here's what I did to solve it:

As it is not possible to avoid the IllegalStateException in the callback, catch & ignore it.

try {
    activity.getSupportFragmentManager().popBackStackImmediate(name);
} catch (IllegalStateException ignored) {
    // There's no way to avoid getting this if saveInstanceState has already been called.
}

This is enough to stop the app from crashing. But now the user will restore the app and see that the button they thought they'd pressed hasn't been pressed at all (they think). The form fragment is still showing!

To fix this, when the dialog is created, make some state to indicate the process has started.

progressDialog.show(fragmentManager, TAG);
submitPressed = true;

And save this state in the bundle.

@Override
public void onSaveInstanceState(Bundle outState) {
    ...
    outState.putBoolean(SUBMIT_PRESSED, submitPressed);
}

Don't forget to load it back again in onViewCreated

Then, when resuming, rollback the fragments if submit was previously attempted. This prevents the user from coming back to what seems like an un-submitted form.

@Override
public void onResume() {
    super.onResume();
    if (submitPressed) {
        // no need to try-catch this, because we are not in a callback
        activity.getSupportFragmentManager().popBackStackImmediate(name);
        submitPressed = false;
    }
}

Upvotes: 150

kim

Reputation: 1057

use remove() instead of popup() if state saved.

   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();
        }
    }
}

Upvotes: 0

no_cola

Reputation: 1160

@Gian Gomen In my case call SUPER solves problem. It seems like more correct solution then commitAllowingStateLoss(), because it solves problem, not hide it.

@Override
public void onRequestPermissionsResult(
     final int requestCode,
     @NonNull final String[] permissions, 
     @NonNull final int[] grantResults
) {
        super.onRequestPermissionsResult(requestCode,permissions, grantResults); //<--- Without this line crash 
        switch (requestCode) {
            case Constants.REQUEST_CODE_PERMISSION_STORAGE:
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    onPermissionGranted(Constants.REQUEST_CODE_PERMISSION_STORAGE);
                }
                break;
        }

Upvotes: 0

Janaco

Reputation: 1683

In my case I got this error in an override method called onActivityResult. After digging I just figure out maybe I needed to call 'super' before.
I added it and it just worked

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data); //<--- THIS IS THE SUPPER CALL
    if (resultCode == Activity.RESULT_OK && requestCode == 0) {
        mostrarFragment(FiltroFragment.newInstance())
    }

}

Maybe you just need to add a 'super' on any override you are doing before your code.

Upvotes: 2

Tapa Save

Reputation: 4857

If you have crash with popBackStack() or popBackStackImmediate() method please try fixt with:

        if (!fragmentManager.isStateSaved()) {
            fragmentManager.popBackStackImmediate();
        }

This is worked for me as well.

Upvotes: 2

Lawrence Kesteloot

Reputation: 4398

If you inherit from FragmentActivity, you must call the superclass in onActivityResult():

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
    super.onActivityResult(requestCode, resultCode, intent);
    ...
}

If you don't do this and try to show a fragment dialog box in that method, you may get OP's IllegalStateException. (To be honest, I don't quite understand why the super call fixes the problem. onActivityResult() is called before onResume(), so it should still not be allowed to show a fragment dialog box.)

Upvotes: 5

Frost Lau

Reputation: 53

The exception is threw here (In FragmentActivity):

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

In FragmentManager.popBackStatckImmediate()，FragmentManager.checkStateLoss() is called firstly. That's the cause of IllegalStateException. See the implementation below:

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);
    }
}

I solve this problem simply by using a flag to mark Activity's current status. Here's my solution:

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();
        }
    }
}

Upvotes: 2

Chandler

Reputation: 3295

Do not use commitAllowingStateLoss(), it should only be used for cases where it is okay for the UI state to change unexpectedly on the user.

https://developer.android.com/reference/android/app/FragmentTransaction.html#commitAllowingStateLoss()

If the transaction happens in ChildFragmentManager of parentFragment, use parentFragment.isResume() outside to check instead.

if (parentFragment.isResume()) {
    DummyFragment dummyFragment = DummyFragment.newInstance();
    transaction = childFragmentManager.BeginTransaction();
    trans.Replace(Resource.Id.fragmentContainer, startFragment);
}

Upvotes: 6

MorZa

Reputation: 2325

In regards to @Anthonyeef great answer, here is a sample code in Java:

private boolean shouldShowFragmentInOnResume;

private void someMethodThatShowsTheFragment() {

    if (this.getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.RESUMED)) {
        showFragment();
    } else {
        shouldShowFragmentInOnResume = true;
    }
}

private void showFragment() {
    //Your code here
}

@Override
protected void onResume() {
    super.onResume();

    if (shouldShowFragmentInOnResume) {
        shouldShowFragmentInOnResume = false;
        showFragment();
    }
}

Upvotes: 2

Irshad Kumail

Reputation: 1273

Courtesy: Solution for IllegalStateException

This issue had annoyed me for a lot of time but fortunately I came with a concrete solution for it. A detailed explanation of it is here.

Using commitAllowStateloss() might prevent this exception but would lead to UI irregularities.So far we have understood that IllegalStateException is encountered when we try to commit a fragment after the Activity state is lost- so we should just delay the transaction until the state is restored.It can be simply done like this

Declare two private boolean variables

 public class MainActivity extends AppCompatActivity {

    //Boolean variable to mark if the transaction is safe
    private boolean isTransactionSafe;

    //Boolean variable to mark if there is any transaction pending
    private boolean isTransactionPending;

Now in onPostResume() and onPause we set and unset our boolean variable isTransactionSafe. Idea is to mark trasnsaction safe only when the activity is in foreground so there is no chance of stateloss.

/*
onPostResume is called only when the activity's state is completely restored. In this we will
set our boolean variable to true. Indicating that transaction is safe now
 */
public void onPostResume(){
    super.onPostResume();
    isTransactionSafe=true;
}
/*
onPause is called just before the activity moves to background and also before onSaveInstanceState. In this
we will mark the transaction as unsafe
 */

public void onPause(){
    super.onPause();
    isTransactionSafe=false;

}

private void commitFragment(){
    if(isTransactionSafe) {
        MyFragment myFragment = new MyFragment();
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.add(R.id.frame, myFragment);
        fragmentTransaction.commit();
    }
}

-What we have done so far will save from IllegalStateException but our transactions will be lost if they are done after the activity moves to background, kind of like commitAllowStateloss(). To help with that we have isTransactionPending boolean variable

public void onPostResume(){
   super.onPostResume();
   isTransactionSafe=true;
/* Here after the activity is restored we check if there is any transaction pending from
the last restoration
*/
   if (isTransactionPending) {
      commitFragment();
   }
}


private void commitFragment(){

 if(isTransactionSafe) {
     MyFragment myFragment = new MyFragment();
     FragmentManager fragmentManager = getFragmentManager();
     FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
     fragmentTransaction.add(R.id.frame, myFragment);
     fragmentTransaction.commit();
     isTransactionPending=false;
 }else {
     /*
     If any transaction is not done because the activity is in background. We set the
     isTransactionPending variable to true so that we can pick this up when we come back to
foreground
     */
     isTransactionPending=true;
 }
}

Upvotes: 3

Levon Petrosyan

Reputation: 9655

To bypass this issue, we can use The Navigation Architecture Component , which was introduced in Google I/O 2018. The Navigation Architecture Component simplifies the implementation of navigation in an Android app.

Upvotes: 1

Samet ÖZTOPRAK

Reputation: 3374

I had the exact same problem. It happened because of the destruction of previous activity. when ı backed the previous activity it was destroyed. I put it base activity (WRONG)

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    SpinnerCustom2.setFragmentManager(getSupportFragmentManager());
    onCreateDrawerActivity(savedInstanceState);
}

I put it into onStart it was RIGHT

@Override
protected void onStart() {
    super.onStart();
    SpinnerCustom2.setFragmentManager(getSupportFragmentManager());

}

Upvotes: 0

ralphgabb

Reputation: 10538

I know there is an accepted answer by @Ovidiu Latcu but after some while, error still persist.

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

Crashlytics still sending me this weird error message.

However error now occurring only on version 7+ (Nougat) My fix was to use commitAllowingStateLoss() instead of commit() at the fragmentTransaction.

This post is helpful for commitAllowingStateLoss() and never had a fragment issue ever again.

To sum it up, the accepted answer here might work on pre Nougat android versions.

This might save someone a few hours of searching. happy codings. <3 cheers

Upvotes: 1

anoop ghildiyal

Reputation: 819

If you are doing some FragmentTransaction in onActivityResult what you can do you can set some boolean value inside onActivityResult then in onResume you can do your FragmentTransaction on the basis of the boolean value. Please refer the code below.

@Override
protected void onResume() {
    super.onResume;
    if(isSwitchFragment){
        isSwitchFragment=false;
        bottomNavigationView.getTabAt(POS_FEED).select();
    }
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == FilterActivity.FILTER_REQUEST_EVENT && data != null) {
        isSwitchFragment=true;
    }
}

Upvotes: 2

android developer

Reputation: 116060

Another possible workaround, which I'm not sure if helps in all cases (origin here) :

@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();
        }
    }
}

Upvotes: 0

Ahmad Melegy

Reputation: 1580

I ended up with creating a base fragment and make all fragments in my app extend it

public class BaseFragment extends Fragment {

    private boolean mStateSaved;

    @CallSuper
    @Override
    public void onSaveInstanceState(Bundle outState) {
        mStateSaved = true;
        super.onSaveInstanceState(outState);
    }

    /**
     * Version of {@link #show(FragmentManager, String)} that no-ops when an IllegalStateException
     * would otherwise occur.
     */
    public void showAllowingStateLoss(FragmentManager manager, String tag) {
        // API 26 added this convenient method
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            if (manager.isStateSaved()) {
                return;
            }
        }

        if (mStateSaved) {
            return;
        }

        show(manager, tag);
    }
}

Then when I try to show a fragment I use showAllowingStateLoss instead of show

like this:

MyFragment.newInstance()
.showAllowingStateLoss(getFragmentManager(), MY_FRAGMENT.TAG);

I came up to this solution from this PR: https://github.com/googlesamples/easypermissions/pull/170/files

Upvotes: 0

Anthonyeef

Reputation: 2675

It's October 2017, and Google makes Android Support Library with the new things call Lifecycle component. It provides some new idea for this 'Can not perform this action after onSaveInstanceState' problem.

In short:

Use lifecycle component to determine if it's correct time for popping up your fragment.

Longer version with explain:

why this problem come out?

It's because you are trying to use FragmentManager from your activity(which is going to hold your fragment I suppose?) to commit a transaction for you fragment. Usually this would look like you are trying to do some transaction for an up coming fragment, meanwhile the host activity already call savedInstanceState method(user may happen to touch the home button so the activity calls onStop(), in my case it's the reason)

Usually this problem shouldn't happen -- we always try to load fragment into activity at the very beginning, like the onCreate() method is a perfect place for this. But sometimes this do happen, especially when you can't decide what fragment you will load to that activity, or you are trying to load fragment from an AsyncTask block(or anything will take a little time). The time, before the fragment transaction really happens, but after the activity's onCreate() method, user can do anything. If user press the home button, which triggers the activity's onSavedInstanceState() method, there would be a can not perform this action crash.

If anyone want to see deeper in this issue, I suggest them to take a look at this blog post. It looks deep inside the source code layer and explain a lot about it. Also, it gives the reason that you shouldn't use the commitAllowingStateLoss() method to workaround this crash(trust me it offers nothing good for your code)
How to fix this?
- Should I use commitAllowingStateLoss() method to load fragment? Nope you shouldn't;
- Should I override onSaveInstanceState method, ignore super method inside it? Nope you shouldn't;
- Should I use the magical isFinishing inside activity, to check if the host activity is at the right moment for fragment transaction? Yeah this looks like the right way to do.
Take a look at what Lifecycle component can do.

Basically, Google makes some implementation inside the AppCompatActivity class(and several other base class you should use in your project), which makes it a easier to determine current lifecycle state. Take a look back to our problem: why would this problem happen? It's because we do something at the wrong timing. So we try not to do it, and this problem will be gone.

I code a little for my own project, here is what I do using LifeCycle. I code in Kotlin.

val hostActivity: AppCompatActivity? = null // the activity to host fragments. It's value should be properly initialized.

fun dispatchFragment(frag: Fragment) {
    hostActivity?.let {
       if(it.lifecyclecurrentState.isAtLeast(Lifecycle.State.RESUMED)){
           showFragment(frag)
       }
    }
}

private fun showFragment(frag: Fragment) {
    hostActivity?.let {
        Transaction.begin(it, R.id.frag_container)
                .show(frag)
                .commit()
    }

As I show above. I will check the lifecycle state of the host activity. With Lifecycle component within support library, this could be more specific. The code lifecyclecurrentState.isAtLeast(Lifecycle.State.RESUMED) means, if current state is at least onResume, not later than it? Which makes sure my method won't be execute during some other life state(like onStop).

Is it all done?

Of course not. The code I have shown tells some new way to prevent application from crashing. But if it do go to the state of onStop, that line of code wont do things and thus show nothing on your screen. When users come back to the application, they will see an empty screen, that's the empty host activity showing no fragments at all. It's bad experience(yeah a little bit better than a crash).

So here I wish there could be something nicer: app won't crash if it comes to life state later than onResume, the transaction method is life state aware; besides, the activity will try continue to finished that fragment transaction action, after the user come back to our app.

I add something more to this method:

class FragmentDispatcher(_host: FragmentActivity) : LifecycleObserver {
    private val hostActivity: FragmentActivity? = _host
    private val lifeCycle: Lifecycle? = _host.lifecycle
    private val profilePendingList = mutableListOf<BaseFragment>()

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    fun resume() {
        if (profilePendingList.isNotEmpty()) {
            showFragment(profilePendingList.last())
        }
    }

    fun dispatcherFragment(frag: BaseFragment) {
        if (lifeCycle?.currentState?.isAtLeast(Lifecycle.State.RESUMED) == true) {
            showFragment(frag)
        } else {
            profilePendingList.clear()
            profilePendingList.add(frag)
        }
    }

    private fun showFragment(frag: BaseFragment) {
        hostActivity?.let {
            Transaction.begin(it, R.id.frag_container)
                    .show(frag)
                    .commit()
        }
    }
}

I maintain a list inside this dispatcher class, to store those fragment don't have chance to finish the transaction action. And when user come back from home screen and found there is still fragment waiting to be launched, it will go to the resume() method under the @OnLifecycleEvent(Lifecycle.Event.ON_RESUME) annotation. Now I think it should be working like I expected.

Upvotes: 42

Sharath kumar

Reputation: 4132

Whenever you are trying to load a fragment in your activity make sure that activity is in resume and not going to pause state.In pause state you may end up losing commit operation that is done.

You can use transaction.commitAllowingStateLoss() instead of transaction.commit() to load fragment

Create a boolean and check if activity is not going to onpause

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

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

then while loading fragment check

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

Upvotes: 2

mojuba

Reputation: 12237

Possibly the smoothest and the simplest solution I found in my case was to avoid popping the offending fragment off the stack in response to activity result. So changing this call in my onActivityResult():

popMyFragmentAndMoveOn();

to this:

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

helped in my case.

Upvotes: 4

Ovidiu Latcu

Reputation: 72341

Please check my answer here. Basically I just had to :

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

Don't make the call to super() on the saveInstanceState method. This was messing things up...

This is a known bug in the support package.

If you need to save the instance and add something to your outState Bundle you can use the following:

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

In the end the proper solution was (as seen in the comments) to use :

transaction.commitAllowingStateLoss();

when adding or performing the FragmentTransaction that was causing the Exception.

Upvotes: 778

Adam

Reputation: 2202

I have also experienced this issue and problem occurs every time when context of your FragmentActivity gets changed (e.g. Screen orientation is changed, etc.). So the best fix for it is to update context from your FragmentActivity.

Upvotes: 0

Vinayakkumar

Reputation: 6520

Short And working Solution :

Follow Simple Steps

Steps

Step 1 : Override onSaveInstanceState state in respective fragment. And remove super method from it.

 @Override
public void onSaveInstanceState( Bundle outState ) {

}

Step 2 : Use fragmentTransaction.commitAllowingStateLoss( );

instead of fragmentTransaction.commit( ); while fragment operations.

Upvotes: 22

Volodymyr

Reputation: 6579

Starting from support library version 24.0.0 you can call FragmentTransaction.commitNow() method which commits this transaction synchronously instead of calling commit() followed by executePendingTransactions(). As documentation says this approach even better:

Calling commitNow is preferable to calling commit() followed by executePendingTransactions() as the latter will have the side effect of attempting to commit all currently pending transactions whether that is the desired behavior or not.

Upvotes: 1

yifan

Reputation: 183

Add this in your activity

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    if (outState.isEmpty()) {
        // Work-around for a pre-Android 4.2 bug
        outState.putBoolean("bug:fix", true);
    }
}

Upvotes: 0

IllegalStateException: Can not perform this action after onSaveInstanceState with ViewPager

Answers (30)

Related Questions