如何从 RecyclerView.Adapter<CardAdapter.ViewHolder> 打开片段

Question

1.TabLayout

- tab1 (Fragment1)
- tab2 (Fragment2)
- tab3 (Fragment3)
     * RecyclerView + CardView (OnClick)

在CardViewClickListner 上打开tab3 中的另一个片段。那么如何在tab3中打开fragment呢。

错误在getFragmentManager():

FragmentTransaction transaction = getFragmentManager().beginTransaction();

而不是这个，我尝试了：

FragmentTransaction transaction = activity.getFragmentManager().beginTransaction();
FragmentTransaction transaction = itemview.getContext().getFragmentManager().beginTransaction();

但是错误没有解决。

这是我的代码：

 public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder> {

    List<NatureItem> mItems;
    private int lastPosition = -1;
    Context context;
    TaskFragment main;
    public CardAdapter(Context context,TaskFragment ma)
    {

        this.context=context;
        main=ma;
    }


    public CardAdapter() {
        super();
        mItems = new ArrayList<NatureItem>();
        NatureItem nature = new NatureItem();
        nature.setName("The Paris Attack 2015");
        nature.setDes("Lorem ipsum dolor sit amet.");
        nature.setThumbnail(R.drawable.news1);
        mItems.add(nature);

           }



    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int position) {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.custom_list, viewGroup, false);
        ViewHolder viewHolder = new ViewHolder(v);

     return viewHolder;
    }


     @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {
        NatureItem nature = mItems.get(i);
        viewHolder.tvNature.setText(nature.getName());
        viewHolder.tvDesNature.setText(nature.getDes());
        viewHolder.imgThumbnail.setImageResource(nature.getThumbnail());
      //  setAnimation(viewHolder.card,i);
    }


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

    class ViewHolder extends RecyclerView.ViewHolder {

        private int lastPosition = -1;
        public ImageView imgThumbnail;
        public TextView tvNature;
        public TextView tvDesNature;
       // Button btnclear,btncancle;
        CardView card;
        Activity activity;
        Context co;
        public ViewHolder(final View itemView) {
            super(itemView);
            imgThumbnail = (ImageView)     itemView.findViewById(R.id.img_thumbnail);
            tvNature = (TextView) itemView.findViewById(R.id.tv_nature);
            tvDesNature = (TextView) itemView.findViewById(R.id.tv_des_nature);
            card = (CardView) itemView.findViewById(R.id.card);



    card.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        Toast.makeText(itemView.getContext(), "Clicked Card...", Toast.LENGTH_LONG).show();

           ShareFragment newFragment = new ShareFragment();
            FragmentTransaction transaction =  getFragmentManager().beginTransaction();
            transaction.replace(R.id.viewFragments, newFragment);
            transaction.addToBackStack(null);
            transaction.commit();

            }
    });

        }
    }
}

Answer 1

在您的 onclick 中按如下方式打开新片段

@Override
        public void onClick(View view){

            AppCompatActivity activity = (AppCompatActivity) view.getContext();
            Fragment myFragment = new MyFragment();
            activity.getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, myFragment).addToBackStack(null).commit();


        }

Answer 2

问题：

Error:cannot find symbol method getSupportFragmentManager() 

解决方案：

当您使用adapter 上下文时，对于访问片段管理器，您需要转换您的context。所以你应该使用这种方式。

YourParentActivity myActivity = (YourParentActivity)context

现在您可以访问片段管理器的方法，例如，

myActivity.getSupportFragmentManager();

但请记住，您的 Fragment 应作为 android.support.app.v4.Fragment 导入，否则可能会出现转换问题。

如果您打开特定标签的片段，那么您应该使用getChildSupportFragmentManager() 而不是getSupportFragmentManager()

注意：如果您想从adapter 类调用fragment，那么您应该创建interface 并将侦听器传递给您的按钮单击方法并使用该接口实现您的活动。 p>

更新：

您也可以将FragmentManager 传递给您的适配器构造函数。喜欢，

public FragmentManager f_manager;
public CardAdapter(Context context,TaskFragment ma , FragmentManager f_manager)
{
    this.context = context;
    this.f_manager = f_manager;
    main=ma;
}

然后你可以在你的适配器类getView()方法中使用this.f_manager。

Answer 3

如果您使用了支持库片段或默认片段，请确保在每个地方都使用相同的片段。并谨慎使用“getSupportFragmentManager”或“getFragmentManager”。

在构造函数中传递上下文。

public CardAdapter(Context context) {
        super();
        mItems = new ArrayList<NatureItem>();
        NatureItem nature = new NatureItem();
        nature.setName("The Paris Attack 2015");
        nature.setDes("Lorem ipsum dolor sit amet.");
        nature.setThumbnail(R.drawable.news1);
        mItems.add(nature);
               }

点击内

....Your Code

ShareFragment newFragment = new ShareFragment();
FragmentTransaction transaction = /* Here is the change.*/context.getFragmentManager().beginTransaction();
    transaction.replace(R.id.viewFragments, newFragment);

...Your Code

更新

Inside onClick call mainActivity setFragment method to replace fragment.

((MainActivity) context).setFragment(yourFragment);


public void setFragment(Fragment frag){
FragmentTransaction transaction = getFragmentManager().beginTransaction();
    transaction.replace(R.id.viewFragments, frag);
}

Answer 4

要从一个片段移动到另一个片段（来自 RecyclerView MyViewHolder 类），请使用此

 Fragment fragment = new AttendanceFragment();
                FragmentManager fragmentManager = ((FragmentActivity) mContext).getSupportFragmentManager();
                FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
                fragmentTransaction.replace(R.id.fragment_container, fragment);
                fragmentTransaction.addToBackStack(null);
                fragmentTransaction.commit();

Answer 5

对于使用 Kotlin 的用户，假设您要启动的片段类名为 MyFragment，并且您将放置此片段的容器的 id 为 fragment_container_view。您可能会在视图持有者的 bind 方法中执行此操作。

itemView.setOnClickListener {
    val activity  = it.context as? AppCompatActivity
    activity?.supportFragmentManager?.commit {
        addToBackStack(MyFragment::class.toString())
        setReorderingAllowed(true)
        replace<MyFragment>(R.id.fragment_container_view)
    }
}

Answer 6

试试这个狙击：

ShareFragment newFragment = new ShareFragment();
MainActivity mainActivity = (MainActivity)itemView.getContext()
mainActivity.getFragmentManager().beginTransaction()
.replace(R.id.viewFragments, newFragment)
.addToBackStack(null)
.commit();