Question

我有一个与RecyclerView相关的查询。我希望获得点击的项目，并在同一布局中将其设置为textview，然后将值设置为textview，更新适配器。

这是我的recyclerview.xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout
        android:id="@+id/rl_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <de.hdodenhof.circleimageview.CircleImageView
            android:id="@+id/imageView_flag"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:layout_marginTop="10dp"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="10dp"
            android:src="@drawable/usa" />

        <TextView
            android:id="@+id/textview_currency_info"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="1 USD(United States of America)"
            android:layout_centerVertical="true"
            android:textColor="#000"
            android:layout_toEndOf="@+id/imageView_flag"
            android:layout_marginStart="14dp" />
    </RelativeLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view_exchange_rate"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/rl_container"/>

</RelativeLayout>

这是我的片段类：

public class ExchangeRatesFragment extends Fragment {

    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    private OnFragmentInteractionListener mListener;
    private String mParam1;
    private String mParam2;

    RetrofitClient retrofitClient;
    RestInterface service;

    ArrayList<ExchangeRate> exchangeRatesArraylist;
    private RecyclerView mRecyclerView;
    private ExchangeRateAdapter exchangeRateAdapter;

    TextView  textview_currency_info;
    ImageView imageView_flag;

    public ExchangeRatesFragment() {}

    public static ExchangeRatesFragment newInstance(String param1, String param2) {
        ExchangeRatesFragment fragment = new ExchangeRatesFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_exchange_rates, container, false);

        exchangeRatesArraylist = new ArrayList<>();

        retrofitClient = new RetrofitClient();
        service = retrofitClient.getAPIClient(WebServiceUrls.DOMAIN_MAIN);

        textview_currency_info = (TextView) rootView.findViewById(R.id.textview_currency_info);
        imageView_flag  = (ImageView) rootView.findViewById(R.id.imageView_flag);

        mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view_exchange_rate);
        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
        mRecyclerView.setLayoutManager(layoutManager);

        get_exchange_rate("USD");
        return rootView;
    }

    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString() + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    public interface OnFragmentInteractionListener {
        void onFragmentInteraction(Uri uri);
    }

    public void get_exchange_rate(String from){
        service.exchange_rate(from, new Callback<JsonElement>() {
            @Override
            public void success(JsonElement jsonElement, Response response) {
                //this method call if webservice success
                try {
                    JSONObject jsonObject = new JSONObject(jsonElement.toString());
                    final JSONArray exchange_rate = jsonObject.getJSONArray("exchange_rate");
                    for(int i=0; i<exchange_rate.length(); i++){
                        JSONObject currencyNews = exchange_rate.getJSONObject(i);
                        String short_name = currencyNews.getString("short_name");
                        String full_name = currencyNews.getString("full_name");
                        String flag = currencyNews.getString("flag");
                        String chang_value =currencyNews.getString("chang_value");
                        ExchangeRate currencyConverter = new ExchangeRate(short_name, full_name, flag, chang_value);
                        exchangeRatesArraylist.add(currencyConverter);
                    }
                    exchangeRateAdapter = new ExchangeRateAdapter(getContext(), exchangeRatesArraylist);
                    mRecyclerView.setAdapter(exchangeRateAdapter);

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void failure(RetrofitError error) {
                Toast.makeText(getActivity(),"Please check your internet connection", Toast.LENGTH_LONG ).show();
            }
        });
    }

这是我的适配器类：

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

    private ArrayList<ExchangeRate> mArrayList;
    private Context context;
    private final LayoutInflater mInflater;

    public ExchangeRateAdapter(Context context, ArrayList<ExchangeRate> arrayList) {
        this.mInflater = LayoutInflater.from(context);
        mArrayList = arrayList;
        context = context;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.exchange_rate_items, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int i) {
        holder.relativeLayout.setOnClickListener(clickListener);

        holder.textView_full_name.setTag(holder);

        holder.textView_short_name.setText(mArrayList.get(i).getShort_name());
        holder.textView_full_name.setText(mArrayList.get(i).getFull_name());
        holder.textview_currency_value.setText(mArrayList.get(i).getChang_value());
        Picasso.with(context).load("http://uploads/country_flag/"+ mArrayList.get(i).getFlag()).into(holder.imageView_flag);
    }

    private View.OnClickListener clickListener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            ViewHolder holder = (ViewHolder) view.getTag();
            int position = holder.getPosition();

            ExchangeRate person = mArrayList.get(position);
            String businessids = person.getFull_name();
            Intent intent = new Intent(context, test.class);
            intent.putExtra("businessids", businessids);
            context.startActivity(intent);
        }
    };

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

    class ViewHolder extends RecyclerView.ViewHolder{
        private TextView textView_short_name, textView_full_name, textview_currency_value;
        private ImageView imageView_flag;
        RelativeLayout relativeLayout;

        ViewHolder(View itemView) {
            super(itemView);
            textView_short_name = (TextView)itemView.findViewById(R.id.textView_short_name);
            textView_full_name = (TextView)itemView.findViewById(R.id.textView_full_name);
            imageView_flag = (ImageView) itemView.findViewById(R.id.imageView_flag);
            textview_currency_value = (TextView)itemView.findViewById(R.id.textview_currency_value);
            relativeLayout = (RelativeLayout) itemView.findViewById(R.id.rl);
        }
    }
}

我尝试了很多在SO上发布的选项，但我没有任何解决方案。如何解决这个问题？当我将onclicklistener设置为ViewHolder时，我在每个项目clicklistener上获取的位置值仅为-1。

Answer 1

一些事情：

当您从单击的视图中获取标记时，您正在"holder.textView_full_name.setTag(holder)"上设置标记（这将是相对布局，因为这是您设置点击监听器的地方(holder.relativeLayout.setOnClickListener(clickListener);)

无论如何这都是必要的。

在您的点击监听器中，调用'getAdapterPosition()'，这应该返回您期望的内容。

修改：Codepath对RecyclerView有一个很好的概述，有点过时，但仍然相关。

Answer 2

您可以使用此依赖项

implementation 'io.reactivex:rxjava:1.2.1'
implementation 'io.reactivex:rxandroid:1.2.1'

仅举例：参考与此一样，您可以单击RecyclerView

 adapter.busNoItemClick().doOnNext(this::getBusNum).subscribe();

 private void getBusNum(String busNo){

    ((TextView)findViewById(R.id.txtBusNumberStudent)).setText(busNo);
}

在适配器中你必须写这个：

  @Override
public void onBindViewHolder(AdapterBusRouteParent.ViewHolder holder, int position) {

    holder.busNumber.setOnClickListener(view -> publishSubject.onNext(busRouteParents.get(position)));

}

  public Observable<String>busNoItemClick(){
    return publishSubject.observeOn(AndroidSchedulers.mainThread());
}

希望这对你有所帮助。

Answer 3

一种方法是拥有

存储所选项目的变量
将OnClickistener设置为ItemView，
在OnClickListener中，将SELECTED_INDEX设置为getAdapterPosition（）并通知适配器。
在onBindViewHolder方法中，检查当前位置是否等于SELECTED_INDEX并执行所需步骤。

int SELECTED_INDEX = 0;


public void setSelectedItemIndex(int position){
    SELECTED_INDEX = position;
    /*if(adapterCallback!=null) { //If you have a callback interface
        adapterCallback.onItemClick(position);
    }*/
    notifyDataSetChanged();
}

持有人类别：

public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

    //Item Declarations

    public MyViewHolder(View itemView) {
        super(itemView);
        //View Binding
        itemView.setOnClickListener(this);
    }


    @Override
    public void onClick(View v){
        if(v==itemView){
            setSelectedItemIndex(getAdapterPosition());
        }
    }
}

在onBindViewHolder方法中：

@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
    if(position==SELECTED_INDEX){
        //Implement your steps
    }
    else{
        //Default Value
    }
}

希望它有所帮助！

如何从RecyclerView itemclicklistener获取点击的项目并将其设置为textview？

3 个答案: