IllegalStateException: fragment already added to tabhost fragment

Question

FATAL EXCEPTION: main
Process: com.example.loan, PID: 24169
java.lang.IllegalStateException: Fragment already added: FormFragment{428f10c8 #1 id=0x7f050055 form}
    at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1192)
    at android.support.v4.app.BackStackRecord.popFromBackStack(BackStackRecord.java:722)
    at android.support.v4.app.FragmentManagerImpl.popBackStackState(FragmentManager.java:1533)
    at android.support.v4.app.FragmentManagerImpl$2.run(FragmentManager.java:489)
    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1484)
    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:450)
    at android.os.Handler.handleCallback(Handler.java:733)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5068)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
    at dalvik.system.NativeStart.main(Native Method)

So, I have an Android app that is created using tabhost. There are three tabs in total, on tab 2 there is a button for performing a fragment transaction on tab 2 (which calls the function in the fragment operation)

FragmentTransaction t = getSupportFragmentManager().beginTransaction();
        t.replace(R.id.realtabcontent, mFrag);
        t.addToBackStack(null);
        t.commit();

There is an exception if I run like this:

1. Inside tab 2, I press a button to change the fragment
2. Go to another tab (e.g. tab 1 or tab 3)
3. Press the back button
4. Throw an exception

How to fix it? thanks for the help

Answer 1

, DialogFragment , ,

if(mFragment.isAdded())
{
     return; //or return false/true, based on where you are calling from
}

, , , , .

Answer 2

, , :

FragmentManager fm = getSupportFragmentManager();
Fragment oldFragment = fm.findFragmentByTag("fragment_tag");
if (oldFragment != null) {
    fm.beginTransaction().remove(oldFragment).commit();
}
MyFragment newFragment = new MyFragment();
fm.beginTransaction().add(newFragment , "fragment_tag");

Answer 3

, :

if(!isAdded())
{
    return;
}

isAdded = true, . . ,

:
http://developer.android.com/reference/android/app/Fragment.html#isAdded()

Answer 4

 if (!fragmentOne.isAdded()){
            transaction = manager.beginTransaction();
            transaction.add(R.id.group,fragmentOne,"Fragment_One");
            transaction.commit();
 }

...

Answer 5

- , . . , , , recyclerview. .

, .

Answer 6

:

Fragment oldFragment = manager.findFragmentByTag(READER_VIEW_POPUP);
if (oldFragment != null) {
    manager.beginTransaction().remove(oldFragment).commit();
}

FragmentTransaction ft = manager.beginTransaction();
ft.add(this, tag);
ft.commit();

Answer 7

, FragmentStatePagerAdapter ViewPager , :

override fun getItem(position: Int): Fragment {
    return tabs[0] // Right variant: tabs[position]
}

(private val tabs: List<Fragment> - ).

Answer 8

, , :

if (!FirebaseManager.isClientA && !FirebaseManager.isClientB) {
      fragment = new FragmentA();
      getFragmentManager().beginTransaction().add(R.id.fragment_frame, fragment, null).addToBackStack("").commit();
} else if (FirebaseManager.isClientB) {
      fragment = new FragmentB();
} else {
      fragment = new FragmentC();
}
getFragmentManager().beginTransaction().add(R.id.fragment_frame, fragment, null).addToBackStack("").commit();

, .

Answer 9

,

FragmentTransaction t = getSupportFragmentManager().beginTransaction();
    t.replace(R.id.realtabcontent, mFrag);
    t.addToBackStack(null);
    t.commitNowAllowingStateLoss();

Answer 10

:

 if (dialogFolderGallery.isAdded()) {
                dialogFolderGallery.dismiss();
            } else { //bla...bla..
}