我无法从 RecyclerView 适配器调用 ViewPager 中的方法

问题描述

每当用户单击 recyclerview 中的项目时，我都不想调用将相应片段添加到 viewpager 的方法。我该怎么做？？，下面是我的代码。谢谢

SemesterFragmentViewPager.java

 public SemesterFragmentViewPager() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_semester,container,false);
        viewPager2 = (ViewPager2) view.findViewById(R.id.viewPager2);
        tabLayout = view.findViewById(R.id.tabLayout);
        adapter = new MyViewPager(getChildFragmentManager(),this.getLifecycle());
        viewPager2.setAdapter(adapter);
        new TabLayoutMediator(tabLayout,viewPager2,new TabLayoutMediator.TabConfigurationStrategy() {
                    @Override
                    public void onConfigureTab(@NonNull TabLayout.Tab tab,int position) {
                        tab.setText("Sem" + (position + 1));
                    }
                }).attach();


//        addComputerScienceSem();
//        cs();

        adapter.notifyDataSetChanged();
        return view;
    }

    public void addComputerScienceSem() {
        adapter.addFrags(Semesters.newInstance(0,0));
        adapter.addFrags(Semesters.newInstance(0,1));
        adapter.addFrags(Semesters.newInstance(0,2));
        adapter.addFrags(Semesters.newInstance(0,3));
    }
    public void cs(){
        adapter.addFrags(Semesters.newInstance(0,4));
        adapter.addFrags(Semesters.newInstance(0,5));
    }
}

我想在下面实现的是，当 case 为 0 时，我应该调用 cs() method from SemesterFragmentViewPager.java，但为什么不起作用

部门RVAdapter.java

 public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        imgDeplogo = itemView.findViewById(R.id.imgDeptlogo);
        tvDepName = itemView.findViewById(R.id.tvDepName);
        tvDepName.setonClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               clickInterface.onItemClickListener(getLayoutPosition());
             switch (getAdapterPosition()){
                   
                    case 0:
                                                  Objects.requireNonNull(departmentFragment.getActivity()).getSupportFragmentManager()
                              .beginTransaction()
                              .replace(R.id.frameLayout,new SemesterFragmentViewPager().cs())// it Couldnt work
                              .addToBackStack(null).
                              commit();
                        break;

当 case 为 1 时，我应该调用 addComputerScienceSem() method from SemesterFragmentViewPager.java，但不起作用

case 1:
                            Objects.requireNonNull(departmentFragment.getActivity()).getSupportFragmentManager()
                                    .beginTransaction()
                                   // .setCustomAnimations(R.anim.slide_in_left,R.anim.exit_to_left,R.anim.enter_from_right,R.anim.exit_to_left)
                                    .replace(R.id.frameLayout,new SemesterFragmentViewPager().addComputerScienceSem())// it Couldnt work too
                                    .addToBackStack(null).
                                    commit();
                    break;

MyViewPager.java

public class MyViewPager extends FragmentStateAdapter {
    List<Fragment> fragmentList = new ArrayList<>();

    public MyViewPager(@NonNull FragmentManager fragmentManager,@NonNull Lifecycle lifecycle) {
        super(fragmentManager,lifecycle);
    }
    @NonNull
    @Override

    public Fragment createFragment(int position) {
       return fragmentList.get(position);
    }
    @Override
    public int getItemCount() {
        return fragmentList.size();
    }
    public void addFrags(Fragment fragment){
        fragmentList.add(fragment);
    }
}

解决方法

第 1 步：您应该创建回调（接口）

interface HandleClickItemsRecycleview{
 void onclickItemRecycleView()
}

并设置为Adapter Recycleview Constructor

第 2 步：使用 SemesterFragmentViewPager 实现回调

SemesterFragmentViewPager implement HandleClickItemsRecycleview

功能覆盖

 void onClickItemRecyleview(){
// Action Add Fragment To ViewPager.
}

关于上面recycleview item点击事件处理的响应 .希望对你有用