Question

我完全陷入了以下问题。我有五个Fragments。

始终会显示

FragA和FragB。从包含两个条目的选项菜单中我想： menuEntryA：显示/添加FragC并移除/隐藏/取消FragD和FragE menuEntryB：显示/添加FragD和FragE并删除/隐藏/分离FragC

Fragments /类仍然可以存在，但不能显示它们。我达到的只是Fragment变为白色，但它仍然占据Fragment列表中的位置，当向前向后滑动Fragments时，它再次出现。

启动应用程序后

在selecton optionsMenuA之后

向右和向后滑动

这是我的代码，请给我提示填写必要的代码。我在这方面工作了好几个小时，但我没有取得任何成功。

    private void setupViewPager(CustomViewPager viewPager) {

   mAdapter = new ViewPagerAdapter(getSupportFragmentManager());

   fragA = new FrgA();   
   fragB = new FrgB(); 
   fragC = new FrgC(); 
   fragD = new FrgD(); 
   fragE = new FrgE(); 

   mAdapter.addFragment( fragA, getString(R.string.frag_title_A));
   mAdapter.addFragment( fragB, getString(R.string.frag_title_B));
   mAdapter.addFragment( fragC, getString(R.string.frag_title_C));
   mAdapter.addFragment( fragD, getString(R.string.frag_title_D));
   mAdapter.addFragment( fragE, getString(R.string.frag_title_E));

   viewPager.setAdapter(mAdapter);
   viewPager.setCurrentItem(1);
   viewPager.setPagingEnabled(true);
}


class ViewPagerAdapter extends FragmentStatePagerAdapter {
    private final List<Fragment> myFragmentList = new ArrayList<>();
    private final List<String> myFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
       super(manager);
    }

    @Override
    public Fragment getItem(int position) {
        return myFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return myFragmentList.size();
    }

    public void addFragment(Fragment fragment, String title) {
        boolean found = false;
        for (int i = 0; i < myFragmentList.size(); i++) {
           if (myFragmentList.get(i).getClass().getName().equalsIgnoreCase(fragment.getClass().getName())) {
              found = true;
           }
       }
       if (!found) {
          myFragmentList.add(fragment);
          myFragmentTitleList.add(title);
       }
     }

     @Override
     public CharSequence getPageTitle(int position) {
         return myFragmentTitleList.get(position);
     }

}


protected void optionsMenuA() {

    FragmentManager fm = getSupportFragmentManager();
    FragmentTransaction ft = fm.beginTransaction();

    ft.remove(fragCustomtext);
    //ft.detach(fragCustomtext);
    ft.commit();
    fm.popBackStack("null", FragmentManager.POP_BACK_STACK_INCLUSIVE);


   //show/add FragC 

   //remove/hide/detatch FragD 

   //remove/hide/detatch FragE.

}

protected void optionsMenuB() {

   //show/add FragD

   //show/add FragE 

   //remove/hide/detatch FragC 

}

    <?xml encoding="utf-8"version="1.0"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="eu.angermayr.test.MainActivity">

    <eu.angermayr.test.CustomViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.v4.view.PagerTabStrip
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="top"
            android:paddingBottom="10dp"
            android:paddingTop="0dp" />

    </eu.angermayr.test.CustomViewPager>
</LinearLayout>

Android Fragments隐藏/删除/附加/分离/销毁

0 个答案: