RecyclerView中的单选选项

Question

I am trying to get if a row is clicked background color of row changes to blue and previous selected row background color changes to transparent how can I achieve this

this is my adapter for recycler view

package kva.recyclerview;

import android.content.Context;
import android.graphics.Color;
import android.support.v7.widget.RecyclerView;
import android.text.Layout;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;


public class adapter extends RecyclerView.Adapter<adapter.MyViewHolder> {

    Context context;
    LayoutInflater inflater;
    ArrayList<String> arrayList;
    public adapter(Context context, ArrayList<String> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
        inflater = LayoutInflater.from(context);
    }

    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = inflater.inflate(R.layout.lit_item, parent, false);
        MyViewHolder holder = new MyViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        holder.tvphone.setText(arrayList.get(position));
        holder.tvemail.setText(arrayList.get(position));
        holder.tvname.setText(arrayList.get(position));
      }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {
        TextView tvname;
        TextView tvemail;
        TextView tvphone;

        public MyViewHolder(View itemView) {
            super(itemView);
            tvemail = (TextView) itemView.findViewById(R.id.emailtv);
            tvname = (TextView) itemView.findViewById(R.id.nametv);
            tvphone = (TextView) itemView.findViewById(R.id.phonetv);

        }
    }
}

My mainactivity

public class MainActivity extends AppCompatActivity {
RecyclerView recyclerView;
    adapter adapter;
    View oldView=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ArrayList<String> arrayList=new ArrayList<String>();
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");
       arrayList.add("aa");

        recyclerView=(RecyclerView)findViewById(R.id.recView);
        adapter=new adapter(this,arrayList);

        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(adapter);
        recyclerView.addOnItemTouchListener(
                new RecyclerItemClickListener(this, recyclerView ,new RecyclerItemClickListener.OnItemClickListener() {
                    @Override public void onItemClick(View view, int position) {

                          view.setBackgroundColor(Color.BLUE);

                      }

                    @Override public void onLongItemClick(View view, int position) {
                        // do whatever
                    }
                })
        );
    }
}

Answer 1

It is always better to use a mode class to represent data to be loaded into the recycler view. Example,

      public class DataModel {
private String name;

private int type;


public DataModel(String name, int type) {
    this.name = name;
    this.type = type;
}

public int getType() {
    return type;
}

public void setType(int type) {
    this.type = type;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

}

Use such model class to load data. In you bindViewHolder you can make a checking say,

      if (arrayList.get(position).getType() == 1)
        holder.tv_simple_name.setTextColor(mContext.getResources().getColor(R.color.black));
    else if (arrayList.get(position).getType() == 2)
        holder.tv_simple_name.setTextColor(mContext.getResources().getColor(R.color.blue));
    else if (arrayList.get(position).getType() == 3)
        holder.tv_simple_name.setTextColor(mContext.getResources().getColor(R.color.transparent));

Add this line to your recyclerview item onClick

      for (int i = 0; i < arrayList.size(); i++) {
                if (arrayList.get(i).getType() == 2)
                    arrayList.get(i).setType(3);
                else if (itemsList.get(i).getType() == 3)
                    arrayList.get(i).setType(1);
            }
            arrayList.get(position).setType(2);
            notifyDataSetChanged();

While adding items to model class, set initial value of type as 1 for all items