I am creating an Android app, and I have linked aFragmentStatePagerAdapter to a TabBar inside one of my Activities to allow users to slide from Fragment to Fragment. Each Fragment in this Activity is populated by a REST call, and if it fails, a Dialog will pop-up saying you should try and refresh your information (only the first time you view the Fragment). The problem I am having is that since FragmentStatePagerAdapter creates the neighboring Fragments to the Fragment you are currently on, it is creating the Dialog(s) of said Fragments prematurely (For example if you are on Fragment 3, and Fragment 4 prompts a Dialog, it will show on Fragment 3 instead of Fragment 4). Is there a way to turn off the creation of neighboring Fragments using a FragmentStatePagerAdapter?
Thank You!
You can control the number of neighboring fragments that area created by calling setOffscreenPageLimit, but the minimum is 1.
Instead of creating your Dialogs in the fragments' onCreateView, I would do it setUserVisibleHint instead. That way the dialog is only created when you're certain that the user is on the page.
No i think you can't , Though there is a property for view pager
viewpager.setOffscreenLimit(0) //defaults to 1
but you can try some other solutions
show Dialog in onResume();
make an interface in Acitvity and fire up to it's implementation in Fragment
tab.setOntabselected{
Pageselected(pagenumber)
}
Related
There are already some open threads about this subject but mine is a little different and I can't seem to find out how to do it. This is my problem:
I'm creating a listview (recyclerview) inside a fragment which I put inside my Viewpager. This listview represent a timeline/agenda of the current day. Whenever the user swipe left or right, the exact same listview fragment needs to pop up with different data (data from the day before or after). Whenever you click on one of the items in the listview, the fragment is replaced by a detailed fragment.
This doesn't sounds so hard but here comes the tricky part:
All the examples I see on the internet show different Fragment classes inside the Viewpager which makes it possible to do a transaction from the listfragment to the detailed fragment, and all the examples that use multiple fragments of the same class don't do a transaction to a detailed fragment.
Whenever I'm trying to do the transaction to the detailed fragment, it looks like it can't find the proper fragment container (since there are 3 of the same now). I'm pretty sure of it since the new fragment does appear but the old fragment stays visibile underneath (when I don't use the viewpager it works fine).
If anyone could provide me with a simple example of a viewpager with multiple fragments of the same class that have a transaction to a detailed fragment you would save my day.
Regards
Problem: Upon clicking a button in a fragment inside of the ViewPager the click falls through to the fragment that is behind it and registers the onClickListener() in the behind fragment rather than the current fragment’s onClickListener().
Situation: I have a ViewPager with 4 fragments in it. Each fragment contains a few rows of custom made buttons. Each fragment has it’s own unique view/layout, yet they are all designed similarly.
Set Up: I am using the FragmentPagerAdapter, because I have a short list of pretty static fragments AND because I need to communicate and update each fragment by using an interface, like how the developer docs suggest.
My Idea: Should I switch to the FragmentStatePagerAdapter? So the adapter will destroy the fragments when they are not visible? But in doing this, will I not be able to communicate with the fragments and update them accordingly?
I don’t know how to solve this problem and it has been driving me mad! Any help is appreciated.
Ask me if I need to clarify anything.
The reason that the fragment behind/after/to-the-right of the current fragment in the viewpager was catching the button clicks was because of the use of the PageTransformer class that I used to add a fade out animation to the pages upon sliding. This PageTransformer animation messed everything up on android version 4.1.1 API 16 and version 4.2.2 API 17. SO be weary of using PageTransformer, especially if you want to support older android versions.
Hi I am developing android application in which I am using one activity and two fragments. Consider same example which google explain like one list view and detail view. on click of list item we are rendering respective detail fragment.
So I learn how to do fragment transaction and i come up with two solutions. One which is standard way which google explain that make one interface and implement that interface into main activity. And do fragment transaction there inside main activity.
I tried with another way. when I click on list item inside click listener instead of calling interface I change fragment inside my list fragment only and its working fine.
So i want to know what is difference between those to methods. changing fragment from main activity and changing it from fragment only.
What kind of problem i will face if i implement with second method.i.e. changing from fragment only.
Need Help. Thank you.
What kind of problem i will face if i implement with second
method.i.e. changing from fragment only.
There isn't an actual problem, it's more of a design discussion. Using the second approach means you're making a very specific fragment, one that on a click on one of its rows will make a transaction with a specific fragment on a specific place of the holder activity. This would be a problem if you plan on reusing this fragment.
Suppose you have this ListFragment and you decided that it should be used in five other activities(with different data). Because it has a very precise action when clicking one of its rows, this fragment will always require the holder activity to have a specific container(where the transaction will be done) along the specific detail fragment with which it was initially used. The problem is that in each of those five activities you may want to use a different fragment when clicking a row of the ListFragment, this would require making changes to the class of the ListFragment.
Now suppose you have the same behavior with the interface approach. As the ListFragment doesn't know or care who handles that click event(as it passes it to whoever registers as the listener) you can simply put the ListFragment in the five activities with no problem(so no changes to it at all). In the interface method of the activity you could then implement the desired behavior with whatever fragment you want and in whatever container setup you want.
I'm new in using view pager, I've done everything correctly, I conveted my activities into fragments and put them in FragmentPagerStateAdapter.
When testing it in the emulator, what I noticed is that the onCtreate to the onResume are called one fragment before the actual visibility on the view pager - it makes sense, the device wants to get ready for the next step, but the problem is that I have one fragment which calls a dialog every onStart so that actually happens on the wrong fragment.
What should be done?
You can use an OnPageChangeListener on your ViewPager to detect when you navigate to the right fragment.
In my application I am using ViewPager from the support library- v4
In main screen I have viewPager which got max 5 Fragment, all fragment belongs to one class ArticlePager
Now in main screen there are list on categories, now the content of the pager is based on that selection,
The problem I am having is, I have used FragmentPagerAdapterwhich stores the Fragment and if the fragment is already exist, It will return the old Fragment without recreating it. That things runs perfectly, but Problem Occurs # the time of orientation change.
For instance
If there are 5 View normally in every fragment For the given position, but There are also some which contains 2-3 views. Now if I change the orientation on page No. lets say 5 which contains only 3 view inside.
So, by now in every category on Page 5 I'll got the view containing 3 view, which is not something I want.
In my application each category contains the pagination
Is there any way such that i can destroy and recreate the Fragment on click of category? or any other work around
Thank you
OK thanks to open source I find my solution, FragmentPagerAdapter I have override the method instantiateItem and got the solution.
This can be easily achieved by FragmentStatePagerAdapter such that it doesn't store the fragment. It recreate it all the time, but I don't want that in 100's of page because of only few pages.
So if I understand correctly, your problem is that after rotation, the wrong set of fragments are in you ViewPager?
Why don't you check the current selected tab in onResume() or onStart() of your Activity, and create/assign a new PagerAdapter for you ViewPager with the correct fragments?