在ViewPager 2中动态删除片段时，它总是删除最后一个片段

问题描述

在ViewPager 2中动态删除片段时，它总是删除最后一个片段，但在添加片段期间没有问题，我尝试为每个Fragment条目指定一个ID，但该方法无效，但getItemPosition覆盖方法在Viewpager中有效，但在Viewpager2中不可用>

请帮助我解决这个问题，困扰我很多天

ViewPagerFragmentAdapter

public class ViewPagerFragmentAdapter extends FragmentStateAdapter {

private ArrayList<Fragment> arrayList = new ArrayList<>();


public ViewPagerFragmentAdapter(@NonNull FragmentManager fragmentManager,@NonNull Lifecycle lifecycle) {
    super(fragmentManager,lifecycle);
   



}
@NonNull
@Override
public Fragment createFragment(int position) {


    return Test_FRAG.newinstance(position);
}



@Override
public int getItemCount() {
    return arrayList.size();
}




public void addFragment(Test_FRAG test_frag) {
    arrayList.add(test_frag);
    notifyDataSetChanged();
}


public void removefragment(int position) {

    arrayList.remove(position);
    notifyDataSetChanged();


}}

主要活动

public class MainActivity extends AppCompatActivity {

ViewPager2 myViewPager2;
TabLayout tabLayout;
ViewPagerFragmentAdapter myAdapter;

int P;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    tabLayout = findViewById(R.id.tabs);
    myViewPager2 = findViewById(R.id.view_pager);
    myViewPager2.setoffscreenPageLimit(5);
    myAdapter = new ViewPagerFragmentAdapter(getSupportFragmentManager(),getLifecycle());




    
    myAdapter.addFragment(new Test_FRAG());
    myAdapter.addFragment(new Test_FRAG());



    myViewPager2.setAdapter(myAdapter);
    myViewPager2.setUserInputEnabled(false);
    new TabLayoutMediator(tabLayout,myViewPager2,new TabLayoutMediator.TabConfigurationStrategy() {
                @Override
                public void onConfigureTab(@NonNull TabLayout.Tab tab,int position) {
                    tab.setText("Tab " + (position + 1));
                }
            }).attach();





    myViewPager2.registerOnPageChangeCallback(new ViewPager2.OnPageChangeCallback() {
        @Override
        public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {
            super.onPageScrolled(position,positionOffset,positionOffsetPixels);
        }

        @Override
        public void onPageSelected(int position) {
            super.onPageSelected(position);

            Log.e("Selected_Page",String.valueOf(position));
            String info = String.valueOf(position);
            P = position;

        }

        @Override
        public void onPageScrollStateChanged(int state) {
            super.onPageScrollStateChanged(state);
        }
    });

    // set Orientation in  ViewPager2
    myViewPager2.setorientation(ViewPager2.ORIENTATION_HORIZONTAL);

    // myViewPager2.setPageTransformer(new MarginPageTransformer(1500));


}

public void ADD_Fragment(View view) {

    myAdapter.addFragment(new Test_FRAG());
    myAdapter.notifyDataSetChanged();
    myViewPager2.setCurrentItem(tabLayout.getTabCount());
    tabLayout.setSelected(true);

}

public void Close_Fragment(View view) {

  int pos = myViewPager2.getCurrentItem();
    myAdapter.removefragment(pos);
    myAdapter.notifyDataSetChanged();



}
}

解决方法

您定位的片段错误！

arrayList.remove(getItemCount())将始终删除您的最后一个片段（恰好与您的片段计数相对应）。

改为使用该职位。类似于：arrayList.remove(position)