问题描述

需要一些帮助来解决我在使用 viewpager 时更新页面的问题.我正在使用带有 FragmentStatePagerAdapter 的简单 viewpager.我想要做的就是访问当前的片段/视图，以便我可以更新我的片段/视图中的一些文本视图.我在论坛里搜索了一下，知道的东西很少- 处理此问题的方法之一是在适配器的 instanceiteItem() 回调中设置标记并通过 findViewbyTag 检索视图.我无法理解如何实现这一点，我也不确定这是否适用于 FragmentStatePagerAdapter.- 我探索了各种论坛中建议的其他选项，但无法使它们发挥作用.

Need some help with my problem of updating pages while using viewpager. I am using a simple viewpager with FragmentStatePagerAdapter. All I want to do is get access to the current fragment/view so as I can update some textviews in my fragment/view. I searched around in the forum and came to know few things - One of the ways to handle this is by setting tag in instantiateItem() call back of the adapter and retreive the view by findViewbyTag. I could not understand how to implement this and I am also not sure if that will work for FragmentStatePagerAdapter. - I explored other options as suggested in various forums, but cannot make them work.

我的代码与 android http://developer.android.com/training 中的代码非常相似/animation/screen-slide.html.基本组件是相同的(带有一些显示组件的片段活动 xml，包括 textview、viewpager xml，其中只有一个视图分页器、一个 Fragment 类和主要的 FragmentActivity 类).在我的 FragmentActivity 类中，我向我的 viewpager 添加了一个 pageChangelistener，以便我可以在 onPageSelected() 期间更改我的 textview.

My code is very much same as in a android http://developer.android.com/training/animation/screen-slide.html. Basic components are the same (Fragment activity xml with some display components including a textview, viewpager xml with just a view pager in it, a Fragment class and the main FragmentActivity class). in my FragmentActivity class I have added a pageChangelistener to my viewpager so as I can do my textview changes during onPageSelected().

感谢任何帮助.

添加代码供参考.

Public class myActivity extends FragmentActivity
  //Variable declarations
  protected void onCreate(Bundle savedInstanceState) {
  ViewPager mPager = (ViewPager) findViewById(R.id.pager);
  mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
  mPager.setAdapter(mPagerAdapter);
  View CurrView;

  OnPageChangeListener pageChangelistener = new OnPageChangeListener() {
    @Override
    public void onPageSelected(int pageSelected) {
       doTextViewChnges();//access the text view and update it based on pageSelected

   ---THIS IS WHERE I AM STUCK IN TRYING TO GET THE TEXTVIEW IN MY CURRENT FRAGMWNT/VIEW-------
   }

  mPager.setOnPageChangeListener(pageChangelistener);
 }
  private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter { 
    public ScreenSlidePagerAdapter(android.support.v4.app.FragmentManager  fm) {
        super(fm);
    }

    @Override
    public android.support.v4.app.Fragment getItem(int position) { 
        return ScreenSlidePageFragment.create(position, <other parameters I want to pass>);
    }

    @Override
    public int getCount() {
        return NUM_PAGES;
    }
}

推荐答案

在你的 OnPageChangeListener 中:

in your OnPageChangeListener:

      OnPageChangeListener pageChangelistener = new OnPageChangeListener() {
            @Override
            public void onPageSelected(int pageSelected) {
 ScreenSlidePageFragment currentFragment = (ScreenSlidePageFragment) mPagerAdapter.getItem(pageSelected)
               doTextViewChnges();//access the text view and update it based on pageSelected

           ---THIS IS WHERE I AM STUCK IN TRYING TO GET THE TEXTVIEW IN MY CURRENT FRAGMWNT/VIEW-------
           }

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