Android Учебник: создание RecyclerView, CardView и меню опций для элемента RecyclerView

Android Учебник: создание RecyclerView, CardView и меню опций для элемента RecyclerView

В этом уроке вы узнаете, как создать простое приложение с помощью RecyclerView, CardView для отображения данных, а затем добавить меню опций (options menu) для элементов списка.

Пример кода:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.gnirt69.recyclerviewoptionmenu.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/recyclerView"></android.support.v7.widget.RecyclerView>
</RelativeLayout>

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

    <android.support.v7.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        android:elevation="4dp">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="@dimen/activity_horizontal_margin">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/txtTitle"
                android:text="Title"
                android:textAppearance="?android:textAppearanceLarge"/>
            <TextView
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/txtDescription"
                android:text="Description"
                android:textAppearance="?android:textAppearanceMedium"
                android:layout_below="@id/txtTitle"/>
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="&#8942;"
                android:id="@+id/txtOptionDigit"
                android:textAppearance="?android:textAppearanceLarge"
                android:layout_alignParentTop="true"
                android:layout_alignParentRight="true"
                android:paddingLeft="@dimen/activity_horizontal_margin"/>
        </RelativeLayout>
    </android.support.v7.widget.CardView>
</LinearLayout>

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private MyAdapter adapter;
    private List<RecyclerItem> listItems;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        listItems = new ArrayList<>();
        //Generate sample data

        for (int i = 0; i<10; i++) {
            listItems.add(new RecyclerItem("Item " + (i + 1), "Welcome to Torisan channel, this is description of item " + (i+1)));
        }

        //Set adapter
        adapter = new MyAdapter(listItems, this);
        recyclerView.setAdapter(adapter);
    }
}

import android.content.Context;
import android.support.v7.widget.PopupMenu;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

import java.util.List;

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

    private List<RecyclerItem> listItems;
    private Context mContext;

    public MyAdapter(List<RecyclerItem> listItems, Context mContext) {
        this.listItems = listItems;
        this.mContext = mContext;
    }

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

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

        final RecyclerItem itemList = listItems.get(position);
        holder.txtTitle.setText(itemList.getTitle());
        holder.txtDescription.setText(itemList.getDescription());
        holder.txtOptionDigit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Display option menu

                PopupMenu popupMenu = new PopupMenu(mContext, holder.txtOptionDigit);
                popupMenu.inflate(R.menu.option_menu);
                popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    @Override
                    public boolean onMenuItemClick(MenuItem item) {

                        switch (item.getItemId()) {
                            case R.id.mnu_item_save:
                                Toast.makeText(mContext, "Saved", Toast.LENGTH_LONG).show();
                                break;
                            case R.id.mnu_item_delete:
                                //Delete item
                                listItems.remove(position);
                                notifyDataSetChanged();
                                Toast.makeText(mContext, "Deleted", Toast.LENGTH_LONG).show();
                                break;
                            default:
                                break;
                        }
                        return false;
                    }
                });
                popupMenu.show();
            }
        });
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder{

        public TextView txtTitle;
        public TextView txtDescription;
        public TextView txtOptionDigit;
        public ViewHolder(View itemView) {
            super(itemView);
            txtTitle = (TextView) itemView.findViewById(R.id.txtTitle);
            txtDescription = (TextView) itemView.findViewById(R.id.txtDescription);
            txtOptionDigit = (TextView) itemView.findViewById(R.id.txtOptionDigit);
        }
    }
}

public class RecyclerItem {

    private String title;
    private String description;

    public RecyclerItem(String title, String description) {
        this.title = title;
        this.description = description;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }
}

Пример кода скачать