根据我的经验，最好的解决方案是:https://stackoverflow.com/a/44177688/3118950，它覆盖了很长的getItemId()，并返回唯一的ID，而不是默认位置。除了这个答案被导入，注意旧的片段将保留在片段管理器中，以防总金额小于页面限制，并且当片段被替换时，onDetach()/ ondestroy()将不会被调用。

我只是把这个答案贴出来，以防其他人觉得有用。为了做完全相同的事情，我只是从兼容性库中获取了ViewPager和PagerAdapter的源代码，并在我的代码中编译它(您需要整理所有错误并导入，但这肯定是可以做到的)。

然后，在CustomViewPager中，创建一个名为updateViewAt(int position)的方法。视图本身可以从ViewPager类中定义的ArrayList mItems中获得(您需要在实例化项目时为视图设置一个Id，并将这个Id与updateViewAt()方法中的位置进行比较)。然后可以根据需要更新视图。

在OP提出他的问题两年半之后，这个问题仍然，嗯，仍然是一个问题。显然谷歌在这方面的优先级不是特别高，所以我没有找到解决方案，而是找到了一个变通办法。对我来说，最大的突破是找到了问题的真正原因(见本文中公认的答案)。一旦问题明显是任何活动页面都没有正确刷新，我的解决方法就很明显了:

在我的片段(几页)中:

I took all the code which populates the form out of onCreateView and put it in a function called PopulateForm which may be called from anywhere, rather than by the framework. This function attempts to get the current View using getView, and if that is null, it just returns. It's important that PopulateForm contains only the code that displays - all the other code which creates FocusChange listeners and the like is still in OnCreate Create a boolean which can be used as a flag indicating the form must be reloaded. Mine is mbReloadForm Override OnResume() to call PopulateForm() if mbReloadForm is set.

在我的活动中，我做页面的加载:

Go to page 0 before changing anything. I'm using FragmentStatePagerAdapter, so I know that two or three pages are affected at most. Changing to page 0 ensures I only ever have the problem on pages 0, 1 and 2. Before clearing the old list, take it's size(). This way you know how many pages are affected by the bug. If > 3, reduce it to 3 - if you're using a a different PagerAdapter, you'll have to see how many pages you have to deal with (maybe all?) Reload the data and call pageAdapter.notifyDataSetChanged() Now, for each of the affected pages, see if the page is active by using pager.getChildAt(i) - this tells you if you have a view. If so, call pager.PopulateView(). If not, set the ReloadForm flag.

在此之后，当您重新加载第二组页面时，该错误仍然会导致一些页面显示旧数据。但是，现在它们将被刷新，您将看到新的数据-您的用户不会知道页面是不正确的，因为这种刷新将在他们看到页面之前发生。

希望这能帮助到一些人!

你可以动态更新所有的片段，你可以在三个步骤中看到。

在适配器中:

public class MyPagerAdapter extends FragmentPagerAdapter {
private static int NUM_ITEMS = 3;
private Map<Integer, String> mFragmentTags;
private FragmentManager mFragmentManager;

public MyPagerAdapter(FragmentManager fragmentManager) {
    super(fragmentManager);
    mFragmentManager = fragmentManager;
    mFragmentTags = new HashMap<Integer, String>();
}

// Returns total number of pages
@Override
public int getCount() {
    return NUM_ITEMS;
}

// Returns the fragment to display for that page
@Override
public Fragment getItem(int position) {
    switch (position) {
        case 0:
            return FirstFragment.newInstance();
        case 1:
            return SecondFragment.newInstance();
        case 2:
            return ThirdFragment.newInstance();
        default:
            return null;
    }
}

// Returns the page title for the top indicator
@Override
public CharSequence getPageTitle(int position) {
    return "Page " + position;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    Object object = super.instantiateItem(container, position);
    if (object instanceof Fragment) {
        Fragment fragment = (Fragment) object;
        String tag = fragment.getTag();
        mFragmentTags.put(position, tag);
    }
    return object;
}

public Fragment getFragment(int position) {
    Fragment fragment = null;
    String tag = mFragmentTags.get(position);
    if (tag != null) {
        fragment = mFragmentManager.findFragmentByTag(tag);
    }
    return fragment;
}}

现在在你的活动中:

public class MainActivity extends AppCompatActivity implements ViewPager.OnPageChangeListener{

MyPagerAdapter mAdapterViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ViewPager viewPager = (ViewPager) findViewById(R.id.vpPager);
    mAdapterViewPager = new MyPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(mAdapterViewPager);
    viewPager.addOnPageChangeListener(this);
}

@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

}

@Override
public void onPageSelected(int position) {

    Fragment fragment = mAdapterViewPager.getFragment(position);
    if (fragment != null) {
        fragment.onResume();
    }
}

@Override
public void onPageScrollStateChanged(int state) {

}}

最后在你的片段中，是这样的:

public class YourFragment extends Fragment {

// newInstance constructor for creating fragment with arguments
public static YourFragment newInstance() {

    return new YourFragment();
}

// Store instance variables based on arguments passed
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

// Inflate the view for the fragment based on layout XML
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment, container, false);
}


@Override
public void onResume() {
    super.onResume();

    //to refresh your view
    refresh();

}}

您可以在这里看到完整的代码。

谢谢阿尔瓦罗·路易斯·布斯塔曼特。

我把我自己的解决方案留在这里，这是一个变通办法，因为问题似乎是FragmentPagerAdapter不清理之前的片段，你可以添加到ViewPager，在片段管理器。所以，在添加FragmentPagerAdapter之前，我创建了一个方法来执行:

(在我的情况下，我从来没有添加超过3个片段，但你可以使用例如getFragmentManager(). getbackstackentrycount()，并检查所有的片段。

/**
 * this method is solving a bug in FragmentPagerAdapter which don't delete in the fragment manager any previous fragments in a ViewPager.
 *
 * @param containerId
 */
public void cleanBackStack(long containerId) {
    FragmentTransaction transaction = getFragmentManager().beginTransaction();
    for (int i = 0; i < 3; ++i) {
        String tag = "android:switcher:" + containerId + ":" + i;
        Fragment f = getFragmentManager().findFragmentByTag(tag);
        if (f != null) {
            transaction.remove(f);
        }
    }
    transaction.commit();
}

我知道这是一种变通方法，因为如果框架创建标签的方式发生变化，它将停止工作。

(当前为"android:switcher:" + containerId + ":" + i ")

那么使用方法是在得到容器之后:

ViewPager viewPager = (ViewPager) view.findViewById(R.id.view_pager);
cleanBackStack(viewPager.getId());

After a lot of searching for this problem, I found a really good solution that I think is the right way to go about this. Essentially, instantiateItem only gets called when the view is instantiated and never again unless the view is destroyed (this is what happens when you override the getItemPosition function to return POSITION_NONE). Instead, what you want to do is save the created views and either update them in the adapter, generate a get function so someone else can update it, or a set function which updates the adapter (my favorite).

所以，在你的MyViewPagerAdapter中添加一个变量:

private View updatableView;

在你的instantiateItem:

 public Object instantiateItem(View collection, int position) {
        updatableView = new TextView(ctx); //My change is here
        view.setText(data.get(position));
        ((ViewPager)collection).addView(view);
        return view;
    }

通过这种方式，你可以创建一个函数来更新你的视图:

public updateText(String txt)
{
    ((TextView)updatableView).setText(txt);
}

希望这能有所帮助!