I'm making an app with 4 tabs, the third one is ListView with data parsed from xml by AsyncTask.
I've got a problem with throbber (circle progress bar) which shows on a previous tab and I can't find solution of it.
Does anybody knows how to prevent this kind of pre-loading when AsyncTask starts on previous tab, not on ListView (third) tab?
There is no way to prevent pre-loading fragments in ViewPager.
But you can use some external libraries to take that result.
For example, ViewPagerExtensions or ViewPagerIndicator.
Related
Am running in some weird problem. I have implemented ViewPagerTabStrip by following the tutorial Here
It's working fine and i have implemented Three Tabs.
On the first Page /tab , i am loading the data from server & displaying it in the ListView
The problem is, when i swipe to the Third Page & then i swipe back to Second page, the data of the first page is being loaded from the server again.( View of first tab is re-created.)
From the logs, it seems that this is the behavior of ViewPager & Adapter.
When we are on the first tab, it creates the view of second tab/ page as well in background & when we are on the Second tab, it was doing same for Third tab in background & upon reaching to third tab, it didn't created the view for it self(i.e third tab).
But when we swipe back to second tab, it re created the view of first tab as well.
How to solve this ? we can't afford to load the data from server again and again while swiping through the tabs.
I mean is there any way to stop the reload of data (or re-creation of view) while just swiping through tab pages? It should load the data when the whole fragment activity of View Pager is created and not at the time of swiping.
Any help on this please ?
Yeah, the ViewPager only keeps a certain number of fragments in memory before destroying them- this default number is usually two. Thus, what you have to do is tell the ViewPager to retain those fragments.
The simplest solution is to simply tell the ViewPager to keep three fragments in memory as follows:
viewPager.setOffscreenPageLimit(3);
Here are a few suggested answers on how to retain fragments (with more than just this method) and the reasoning behind the default behaviour as well as these solutions:
ViewPager and fragments — what's the right way to store fragment's state?
retain state of viewpager fragments android
I am using ViewPager. I have 3 fragments (A,B,C) and two of them(A & C) are populating ListView from the server, so it will take a few seconds for that. And I am showing a ProgressDialog. B is the fragment which is set to show first and its is not having any background process, having a few buttons only.
So the problem is that the ProgressDialog will always show upon creating that activity,that is all the Fragments are loaded always.
So I wonder if I can load the specific Fragment only (A or C) when I open it (Slide) so that the user who want to use the Icon menu (B fragment) should not need to wait for the other fragments (A & C) to load. I am not sure whether its possible or not. Can anyone suggest me any code snippets or references to achieve it. Any help regarding this will be really appreciated.
Nevermind, I had done it easily with AsyncTask and the Fragments are updated in background
I am developing an app in Android using Fragments. I have this three tabs:
I know that is not possible to prevent the load of one fragment on each side (previous and next) as far as the minimum value of setOffScreenPageLimit() is 1 but does it mean that if I want to show a ProgressDialog on the onPreExecute method of an AsyncTask running within Descargas Fragment this will cause that when I nav to the Capturador that ProgressDialog will be necessarily loaded? If yes I have no idea of how to let the user know that I am downloading the packages (that's what Descargas does, to parse some XML).
Thanks in advance ;)
Embed a ProgressBar on the Descargas fragment. Or overlay an indeterminate progressbar over the center of the fragment while it loads.
Dialogs are really part of the activity, it wouldn't make sense that it's only applicable to one of the pages.
At the end of the day though if you must insist on using dialogs, you can implement an onPageChangeListener
viewPager.setOnPageChangeListener(OnPageChangeListener);
And you can pull up the appropriate dialog when the designated fragment is selected and the opposite when you navigate away.
I'm using FragmentPagerAdapter with a tabbed interface. My interface happens to have three tabs. I can see that as soon as my app is created, the adapter requests that both tabs one and two both be created immediately (I assume this is so swiping to the next tab appears smooth to the user).
Is there a way to stop the automatic loading of the next tab? My tabs are pretty heavy, and loading two right at startup is taking a good deal of time,
Thanks
Is there a way to stop the automatic loading of the next tab?
Sorry, no. This is driven by setOffscreenPageLimit(), and the minimum value is 1, meaning that ViewPager will always try to create and hold onto at least 1 page on each side.
It sounds like you need to move more logic into background threads.
I want a Viewpager that shows loading while content is coming in from the background. Basically I expect the first View to be loaded, but View+1 and View-1 will still be loading. If the user swipes to either side I want them to be presented with a spinning dialog while it loads
Would I just add AsyncTasks into the ViewPager with some conditions determining when they will run? I dont want too many AsyncTasks to be loading as the viewpager will have many views off to the sides.
I think the Trulia app does this, it is similar to what I am looking for. Apartment image viewing shows a loading screen while the images are loading in that viewpage.
Also for the record, can I just treat viewpagers like onCreate functions of an activity? That would really clear things up
Insight appreciated
Have a look at the supplied FragmentPagerAdapter if you want to perform more Activity-like lifecycle management of each page.