单击我的 RecyclerView 列表中的项目时如何显示 onClick 消息？

Question

I am actually working on a group project and I want to develop a functionnality for our application. My goal is to have a list of several items with their images and when I click on an Item of that list I want to have a text pop in the midle of the screen related to that particular item. I'm afraid I might be using the wrong technical Tools to do so. I am actually using a csv file for the list details, an adapter and a viewHolder for the list. Since I have no idea on what is wrong and what to do I link a big part of my code so you can check how I did until now. I can also give you my xml files if you need to check them out, a really big thanks in advance to all the answers and time spent on my problem

I already managed to have my list of items with the title and the picture (text from csv file) of each list item but I'm stuck on how to show a specific text for each ViewHolder.

this is my Adapter

public class Adapter extends RecyclerView.Adapter<ViewHolder> {

    List<Departement> list;
    Activity activity;

    public Adapter(List<Departement> list, Activity activity) {
        this.list = list;
        this.activity = activity;
    }

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

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int position) {
        Departement departement = list.get(position);
        viewHolder.bind(departement, activity);
    }

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

}

my ViewHolder

public class ViewHolder extends RecyclerView.ViewHolder {
    private TextView textViewView;
    private ImageView imageView;

    public ViewHolder(View itemView) {
        super(itemView);

        textViewView = (TextView) itemView.findViewById(R.id.text);
        imageView = (ImageView) itemView.findViewById(R.id.image);
    }

    public void bind(Departement departement, Activity activity){
        textViewView.setText(departement.getText());
        String uri = departement.getImageUrl();
        int imageResource = activity.getResources().getIdentifier(uri, null, activity.getPackageName());
        Drawable res = activity.getResources().getDrawable(imageResource);
        imageView.setImageDrawable(res);
    }
}

each item of the list is a Departement

public class Departement {
    private String text;
    private String imageUrl;

    public Departement(String text, String imageUrl) {
        this.text = text;
        this.imageUrl = imageUrl;
    }

    public String getText() {
        return text;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setText(String text) {
        this.text = text;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }
}

and finally my fragment

public class FragmentEspecesProches extends Fragment {

    public final static char SEPARATOR=',';

    private RecyclerView recyclerView;

    private List<Departement> departementsList = new ArrayList<>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        View view = inflater.inflate(R.layout.fragment_especes_proches, container, false);

        ajouterDepartements();

        recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);

        recyclerView.setLayoutManager(new GridLayoutManager(this,2));

        recyclerView.setAdapter(new Adapter(departementsList, getActivity()));


        return view;
    }

    private void ajouterDepartements() {

        ArrayList<String> lines = new ArrayList<>();
        ArrayList<String[]> data = new ArrayList<>();
        String sep = new Character(SEPARATOR).toString();

        lines = UtilitaireResultat.readFile(getActivity().getResources().openRawResource(R.raw.departement));

        for(String line : lines){
            String[] oneData = line.split(sep);
            data.add(oneData);
        }

        for(int i=0 ; i<data.size() ; i++){
            String[] tabStr = data.get(i);
            departementsList.add( new Departement( tabStr[2]+" - "+tabStr[3] ,"@drawable/"+tabStr[5] ));
        }


    }

}

Answer 1

you can implement item click listener like this

   public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        public TextView tvName;
        public TextView tvHometown;
        private Context context;

        public ViewHolder(Context context, View itemView) {
            super(itemView);
            this.tvName = (TextView) itemView.findViewById(R.id.tvName);
            this.tvHometown = (TextView) itemView.findViewById(R.id.tvHometown);
            // Store the context
            this.context = context;
            // Attach a click listener to the entire row view
            itemView.setOnClickListener(this);
        }

        // Handles the row being being clicked
        @Override
        public void onClick(View view) {
            int position = getAdapterPosition(); // gets item position
            // if (position != RecyclerView.NO_POSITION) { // Check if an item was deleted, but the user clicked it before the UI removed it
                User user = users.get(position);
                // We can access the data within the views
                Toast.makeText(context, tvName.getText(), Toast.LENGTH_SHORT).show();
           // }
        }
    }

Answer 2

Use onBindViewHolder to handle any interaction on your list items

@Override
    public void onBindViewHolder(ViewHolder viewHolder, int position) {
        Departement departement = list.get(position);
        viewHolder.bind(departement, activity);
        viewHolder.itemView.setOnClickListener(//your action//);
    }

ItemView is the whole item; you can access your textviews or imageviews as you use it on your bind method, You can use your bind method to apply listeners.

Answer 3

Handle on click of the item inside your ViewHolder constructor like ,

 public ViewHolder(View itemView) {
    super(itemView);
    textViewView = (TextView) itemView.findViewById(R.id.text);
    imageView = (ImageView) itemView.findViewById(R.id.image);
    itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
              int position=getAdapterPosition();
              Toast.makeText(context, list.get(position).getText(), Toast.LENGTH_SHORT).show();
        }
    });
}

Answer 4

Create your onClickListner interface as

interface RecylerViewItemClickListner 
{
    void onItemClick(Department item)
}

set the listner in Adapter class

private final RecylerViewItemClickListner mOnClickListener;
public Adapter(List<Departement> list, Activity activity) {
        this.list = list;
        this.activity = activity;
        this.mOnClickListener = activity;
    }

Now in ViewHolder class

public void bind(final Departement item, final mOnClickListener listener) {

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override public void onClick(View v) {
                    mOnClickListener.onItemClick(item);
                }
            });
        }

and change onBindViewHolder as below

 @Override
 public void onBindViewHolder(ViewHolder holder, int position) {
            holder.bind(items.get(position), mOnClickListener);
        }

Override onItemClick(Department item) in activity

@override
onItemClick(Department item)
{
  //show toast here...
}

Answer 5

implement OnClickListener in your ViewHolder class

  public class ViewHolder extends RecyclerView.ViewHolder implements
    View.OnClickListener
    {
                @Override
                public void onClick(View v)
                {
                   //do action
                }
    }

Answer 6

Implement below method in your ViewHolder class.

itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    final User currentItem = users.get(getAdapterPosition());
                    Toast.makeText(mContext,currentItem.getText()+" is selected!",Toast.LENGTH_SHORT).show();

                }
            });