fragmentpageradapter

I have 10 tabs in my activity . As soon as I open the activity the first fragment gets displayed but the method (AsyncTask) present in the next fragment gets called. And if I go to the next tab say 3rd tab then the method present in the 4th fragment gets called and so on. I don't understand this behavior. Please help! You must know how the viewPager works populating the fragment in the different positions When you start on the position 0, then the fragment on the position 0 and the one of the position 1 are created. Then when you swipe to the position 1 the fragment on the 2 position is

在一个 Android 应用中，我使用 FragmentPagerAdapter 来处理多 Fragment 页面的横向滑动。不过我碰到了一个问题，即当 Fragment 对应的数据集发生改变时，我希望能够通过调用 mAdapter.notifyDataSetChanged() 来触发 Fragment 页面使用新的数据调整或重新生成其内容，可是当我调用 notifyDataSetChanged() 后，发现什么都没发生。 搜索之后发现不止我一个人碰到这个问题，大家给出的解决办法五花八门，有些确实解决了问题，但是我总感觉问题没搞清楚。于是我决定搞明白这个问题到底是怎么回事，以及正确的用法到底如何。要搞明白这个问题，仅仅阅读文档并不足够，还需要阅读相关几个类的相关方法的实现，搞懂其设计意图。下面就是通过阅读源代码搞明白的内容。 【ViewPager】 ViewPager 如其名所述，是负责翻页的一个 View。准确说是一个 ViewGroup ，包含多个 View 页，在手指横向滑动屏幕时，其负责对 View 进行切换。为了生成这些 View 页，需要提供一个 PagerAdapter 来进行和数据绑定以及生成最终的 View 页。 setAdapter() ViewPager 通过 setAdapter() 来建立与 PagerAdapter 的联系。这个联系是双向的，一方面

I am new to android and I am stuck at particular section of the app which I am working on. The problem is - I want to navigate to the second tab of HomePageActivity when I perform onClickListener event on createEvent button in my SecondActivity . I tried using solution from various threads here and on other sites too but I was still not able to get my code running. I also have RecyclerView on HomePageActivity which is to be populated based on the click event. Here is the code snippet from both the activities - HomePageActivity.java - Tabbed Activity public class HomePageActivity extends

the title pretty much explains it. I have horizontal scrolling set up, the first screen has buttons to the other Fragments as well as the whole horizontal scroll system. What I would like is for the user to be able to press the back button when on one of these fragments and for the app to return to the first screen with all the buttons. From there I want the back button to be an AlertDialog asking the user if they would like to exit the app. At the moment this is what is happening (On all Fragments when you press the back button the AlertDialog I created pops up). I've looked into Fragment

Basically the situation is like this: I have an Activity , which displays a three Fragments within a FragmentPagerAdapter , and within one of these Fragment , I nest another Fragment . I added the fragments like this: fragmentTransaction = getFragmentManager().beginTransaction(); fragmentTransaction.add(rootView.getId(), new MainPageFragment(), "lpt2"); fragmentTransaction.commit(); When I try to call getParentFragment() inside of MainPageFragment() , it returns null . How can that be? I checked multiple posts here on stackoverflow as well as on other blogs, and they all came to the conclusion

I'm trying to build a Fragment that holds a gridview for a nice UI. I have used some of the sample code to try and build this. Do I really need to keep track and save the state of my fragments for orientation switches (apparently I do) or am I missing something? From the sound of it (it being the FragmentPagerAdapter docs) it seems like the FragmentPagerAdapter saves all states for me... Suffice to say, here is my problem(I have 4 fragments with some textviews in them): 1. When I tilt the screen on Fragment0, the underlying data disappears and will not reappear until I move to Fragment2. 2.

一.页面缓存 ViewPager默认会缓存1~2个页面，也就是当前页面的前一个页面和后一个页面，如果后一个页面不存在，则不在缓存，反之会被缓存 offscreenPageLimit的默认值为1 int offscreenPageLimit = mViewPager.getOffscreenPageLimit(); Log.e("MainActivity", "offscreenPageLimit="+offscreenPageLimit); 1.1轮播图 有时，需要使用ViewPager+反射匀速Scroller+ImageView做轮播图时，轮播的图片超过4个就会出现空白的问题，对于这种问题，明细我们需要把 offscreenPageLimit设置为n-1,(n为图片的个数),这样把图片缓存起来（轮播图一般在首页，长期存在，因此也就不要想着及时释放掉这几张图片了） mViewPager.setOffscreenPageLimit(imageList.size()-1); 二. 当前视图 Fragment更新 ViewPager+Fragment也会受到 offscreenPageLimit的影响，对于这个，建议使用n-1模式 List<BaseFragment> fragmentList = Collections.synchronizedList(new ArrayList

在一个 Android 应用中，我使用 FragmentPagerAdapter 来处理多 Fragment 页面的横向滑动。不过我碰到了一个问题，即当 Fragment 对应的数据集发生改变时，我希望能够通过调用 mAdapter.notifyDataSetChanged() 来触发 Fragment 页面使用新的数据调整或重新生成其内容，可是当我调用 notifyDataSetChanged() 后，发现什么都没发生。 搜索之后发现不止我一个人碰到这个问题，大家给出的解决办法五花八门，有些确实解决了问题，但是我总感觉问题没搞清楚。于是我决定搞明白这个问题到底是怎么回事，以及正确的用法到底如何。要搞明白这个问题，仅仅阅读文档并不足够，还需要阅读相关几个类的相关方法的实现，搞懂其设计意图。下面就是通过阅读源代码搞明白的内容。 【ViewPager】 ViewPager 如其名所述，是负责翻页的一个 View。准确说是一个 ViewGroup ，包含多个 View 页，在手指横向滑动屏幕时，其负责对 View 进行切换。为了生成这些 View 页，需要提供一个 PagerAdapter 来进行和数据绑定以及生成最终的 View 页。 setAdapter() ViewPager 通过 setAdapter() 来建立与 PagerAdapter 的联系。这个联系是双向的，一方面