列表适配器中的回调方法不起作用

Question

我使用了在上一个问题中被指导使用的回调方法。它似乎不起作用。不调用onClick（）方法。回调方法似乎是一个非常广泛的概念。我不知道如何缩小搜索范围以获取相关信息，或者如何找到我得到的代码有什么问题。

ListActivity-适配器已初始化，并在此处设置了单击侦听器

public class ListActivity extends AppCompatActivity implements ListAdapter.ItemClickListener {

    ArrayList<Country> countriesList;
    ListAdapter adapter;
    RecyclerView rv;

    protected void onCreate(@Nullable Bundle savedInstanceState) {

        adapter = new ListAdapter(context, this);
        adapter.setClickListener(this);

        //more irrelevant code
    }
}

    private Country getCurrentCountry(){
        return currentCountry;
    }

    public void setCurrentCountry(Country currentCountry){
        this.currentCountry = currentCountry;
    }

    @Override
    public void onItemClick(View view, int position) {

        FragmentTransaction ft;

        Bundle countryBundle = new Bundle();
        countryBundle.putParcelable("countriesList", getCurrentCountry());

        Fragment countryFragment = new CountryFragment();
        countryFragment.setArguments(countryBundle);
        ft = getSupportFragmentManager().beginTransaction();
        ft.add(R.id.fragments_container, countryFragment);

        Log.d("Monitoring", getCurrentCountry().toString());

        ft.commit();
    }

Adapter类中的回调方法

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.RowViewHolder> {
// Adapter class code
...
    class RowViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        TextView viewName;
        ImageView viewFlag;
        LinearLayout countryEntry;

        RowViewHolder(View view) {

            super(view);
            viewName = view.findViewById(R.id.name);
            viewFlag = view.findViewById(R.id.flag);
            countryEntry = view.findViewById(R.id.rowId);
            view.setOnClickListener(this);
        }

        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
            ListActivity.position = getAdapterPosition();
            final Country currentCountry = countriesList.get(getAdapterPosition());
            listActivity.setCurrentCountry(currentCountry);

        }
    }

    public void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
//more irrelevant code
}

谢谢！

Answer 1

您不需要传递视图和位置，只需传递想要的对象。

更改界面参数

 public interface ItemClickListener {
     void onItemClick(Country country);
 }

您可以传递所需的对象

public void onClick(View view) {

     final Country currentCountry = countriesList.get(getAdapterPosition());

     mClickListener.onItemClick(currentCountry);
}

在您的活动中，获取您的国家/地区

 @Override
 public void onItemClick(Country country) {

      //  get country and do anything you want
 }

希望这会有所帮助

Answer 2

这是因为您在RowViewHolder's onClick方法中缺少@@ Override批注。

它应该看起来像下面。

class RowViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        TextView viewName;
        ImageView viewFlag;
        LinearLayout countryEntry;

        RowViewHolder(View view) {

            super(view);
            viewName = view.findViewById(R.id.name);
            viewFlag = view.findViewById(R.id.flag);
            countryEntry = view.findViewById(R.id.rowId);
            view.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
            ListActivity.position = getAdapterPosition();
            final Country currentCountry = countriesList.get(getAdapterPosition());
            listActivity.setCurrentCountry(currentCountry);

        }
    }