I have this app structure:
MainActivity with a global menu and Fragment container.
First Fragment: a ViewPager with three pages.
Second Fragment: a list
I insert the Fragments on the OnCreate() in the MainActivity and change their visibility with show and hide (using the FragmentTransaction).
When I launch the app the first Fragment appear in the screen without problem, when change to the second Fragment also work like a charm but when I come back to the first Fragment the app doesn't show anything inside the ViewPager.
Are there any particular option that I have to change in the ViewPager to solve this?
The problem seems due to that android does not allow to have nested fragments. In my case I can manage the situation using simple views instead of fragments inside the ViewPager.
I used ViewStub to show/hide ViewPager.
The basic idea was you created ViewStub in layout file, and inflate/setVisible while necessary.
The only trick was, I had to setAdatper to null otherwise it crashed while re-createView when off and on screen.
#Override
public void onDestroyView() {
super.onDestroyView();
viewPager.setAdatper(null);
}
Related
I am currently using a ViewPager with a TabLayout, the ViewPager as of now consists of three separate fragments.
I would like to be able to switch to a fourth fragment using a button on one of the already present fragments.
However, I do not want the fourth fragment to be accessible through the usual ways (aka scrolling) without using the button to reach the fourth fragment. Similarly, I would like scrolling to be disabled when I am currently displaying my fourth fragment.
What would be the best way to do so?
The current hack that I can think of would be to create a hidden fragment within my main layout. I can then display it when the button is pressed while hiding the ViewPager at the same time.
Are there any better ways to do this?
Include your ViewPager in fragment and onClick make replace for the next fragment, and you can return to ViewPager`s fragment onBackPress.
I've created an app, that has a main activity with a drawer menu so the user can click on some option and a fragment is open inside the activity.
What I'd like to do is to have several screens in one of the options and to navigate between them by tabs/slide the screen.
I saw an example of doing it inside one activity and with a fragment per 'sub-screen', my question is: how can I do it when I'm already 'inside' a fragment?
Thanks
Fragments can support having other Fragments inside them. The key to making this work is to remember to use getChildFragmentManager() to get the Fragment's FragmentManager instead of getFragmentManager() which gets the Activity's FragmentManager.
If you want to swipe between views, use a ViewPager inside your Fragment UI. The ViewPager will use a FragmentPagerAdapter to handle the Fragments for display.
I am writing an android app that will have a number of different screens that I would like to swipe between, each screen will be a full page except for action bar header. On each screen there is the ability to open up another screen which will also be multiple screens that I would like swipeable. What is the best way to handle this. Do I have one fragment manager that holds all the screens and handle the onPageScrollStateChanged to only allow swipes between the current accessable screens or would I be best off nesting the fragments. I hope the above makes sense.
Thanks in advance
Sounds like you want to use a ViewPager to to swipe between views (Fragment extends View)
You could either:
In a single activity use a FragmentManager that switches between the parent and child Fragments, each with their own ViewPager and nested Fragments
Start a new activity to hold each ViewPager
Both are valid, if the Fragments need to communicate with each other or the Activity option one might suit the project needs better.
For the swiping between views you indeed need a ViewPager
For the nested fragments I would use a wrapper. I struggled a lot with fragments and found that this is the best way. A wrapper is very simple. This is just a fragment that holds other fragments. In the onCreate() of this fragment you get the childFragmentManager and add the fragment you originionally wanted to add. If you want to go to a new fragment you simply get the childFragmentManager again and replace the current item. This way you have nested fragment. You can add this to the backstack in order to get back navigation, but you need to override onBackPressed() inside your activity and call the method popBackStack() from the fragmentManager in order to get the first fragment back.
If you have any questions, comment below.
I have gotten my tabs up and running with Sherlock Fragments. So i have two tabs and two fragments. Now what i want is that when i click on a button in one of the fragments, I want another fragment to open up, but it should be inside the tab that contained the original fragment. Can anyone show me how this can be done ?
Actually Nested Fragments are not possible directly. I had a similar issue and but the Fragment to be shown was small and simple. So I just played with setVisibility() as LinearLayout.GONE and LinearLayout.VISIBLE
On the Fragment initialization, I hid the second layout and when I need to show the other fragment, I hid the first layout and showed the second layout. It worked great for me!
I'm having a bit of trouble implementing a design based around multiple ViewPagers.
At a high level, I have a FragmentActivity with just a FrameLayout as it's content. I have 3 different Fragments that I want to display. All 3 are full screen and only 1 will be used at a time.
Fragment 1 is a basic fragment with some TextViews and ImageViews.
Fragment 2 has a ViewPager and a FragmentPagerAdapter that feeds it several simple fragments.
Fragment 3 has a ViewPager and a FragmentPagerAdapter that feeds it several simple fragments (that are different from Fragment 2)
In my FragmentActivity onCreate() I get the FragmentManager and begin a transaction to replace whatever is in my FrameLayout with a new instance of Fragment 2.
At this point everything is working as expected. My ViewPager in Fragment 2 works perfectly.
Now I have a menu option that replaces the Fragment 2 in my FrameLayout with a new instance of Fragment 3. This also works fine.
The problem arises when I try to put Fragment 2 back into the FrameLayout with another replace transaction. I see my PagerIndicater at the top, but my pages are blank.
I've tried just creating a new instance of my Fragment 2 and calling a replace transaction. I've also tried setting a tag on my Fragments when I call replace and adding a findFragmentByTag check before my replace instead of creating a new instance. Both gave me the same result of blank pages after my second replace.
For reference
My first design was simply a FragmentActivity with a ViewPager and a ViewIndicater. I only had Fragment 2 and Fragment 3 from my description above and a menu option to switch between them. To switch I had 2 different FragmentPagerAdapters defined and just called ViewPager.setAdapter to set the selected FragmentPagerAdapter. This was working perfectly, but now I need a new top level Fragment that isn't using ViewPager at all. This is why I decided to move my ViewPagers out into their own Fragments. My idea being that I would just swap in my fragments to a FrameLayout.
I don't have my code in front of me right now so I can't post any, but I'll add some code to my question tomorrow to help facilitate answers.
This question is a possible duplicate of Navigating back to FragmentPagerAdapter -> fragments are empty.
If your app can handle it (API 17), use getChildFragmentManager(). This problem seems to occur when using a Fragment to host your ViewPager and using FragmentPagerAdapter. Changing to FragmentStatePagerAdapter seemed to fix the problem as well, but I still think using getChildFragmentManager() is the smartest thing to do.
brockoli you can used not "good way". But for my it's worked.
You can use in view 2 layouts, where you bind fragments. First - for fragment with fragments. Second - for other fragments.
On replace fragment with fragments do not replace, but only change visibility first layout to gone and add new fragment to second layout. On back, remove fragment from second layout and set visibility for first layout to visible.