Androidリストビューできた！

 

[evernote:d03670b6a01be642403ce651d0369c83 アップロード中]

 

ドットインストールさんの力でできたけど、完全に写経状態になりつつあるけど大丈夫ですかね。^^;

自分でアプリを作るときにこういう機能あったなーって感じで思い出して利用できればいいと考えています。

 

Androidリストビュー入門終了

 

• getView()の実装
• adapterの設定

• ViewHolder
• setTag()、getTag()

 

 

package com.example.makabe.mylistviewapp;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ListView myListView = (ListView) findViewById(R.id.myListView);

        //データを準備
        ArrayList users = new ArrayList<>();

        int[] icons = {
                R.mipmap.ic_launcher,
                R.mipmap.ic_launcher,
                R.mipmap.ic_launcher
        };

        String[] names = {
                "Makabe",
                "Yamada",
                "Doujima"
        };

        String[] locs = {
                "Toda",
                "Machida",
                "Shibuya"
        };

        for (int i = 0; i < icons.length; i++) {
            User user = new User();
            user.setIcon(BitmapFactory.decodeResource(
                    getResources(),
                    icons[i]
            ));
            user.setName(names[i]);
            user.setLoc(locs[i]);
            users.add(user);
        }

        //Adapter - ArrayAdapter

        UserAdapter adapter = new UserAdapter(this, 0, users);
        //ListViewに表示
        myListView.setAdapter(adapter);

        //Event
        myListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(
                    AdapterView<?> adapterView,
                    View view,//タップされたView
                    int i,  //何番目？
                    long l//View id
                    ){
                TextView name = (TextView) view.findViewById(R.id.name);
                Toast.makeText(
                        MainActivity.this,
                        Integer.toString(i) + ":" + name.getText().toString(),
                        Toast.LENGTH_SHORT
                ).show();
                name.setText("Tapped!");
            }
        });

    }

    public class UserAdapter extends ArrayAdapter {

        private LayoutInflater layoutInflater;

        public UserAdapter(Context c, int id, ArrayList users) {
            super(c, id, users);
            this.layoutInflater = (LayoutInflater) c.getSystemService(
                    Context.LAYOUT_INFLATER_SERVICE
            );
        }

        @Override
        public View getView(int pos, View convertView, ViewGroup parent) {
            ViewHolder holder;

            if (convertView == null) {
                convertView = layoutInflater.inflate(
                        R.layout.list_item,
                        parent,
                        false
                );
                holder = new ViewHolder();
                holder.icon = (ImageView) convertView.findViewById(R.id.icon);
                holder.name = (TextView) convertView.findViewById(R.id.name);
                holder.loc = (TextView) convertView.findViewById(R.id.loc);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder)convertView.getTag();

            }

            User user = (User) getItem(pos);

            holder.icon.setImageBitmap(user.getIcon());
            holder.name.setText(user.getName());
            holder.loc.setText(user.getLoc());

            return convertView;
        }
    }

    static class ViewHolder {
        ImageView icon;
        TextView name;
        TextView loc;
    }


    public class User {
        private Bitmap icon;

        public Bitmap getIcon() {
            return icon;
        }

        public void setIcon(Bitmap icon) {
            this.icon = icon;
        }

        public String getLoc() {
            return loc;
        }

        public void setLoc(String loc) {
            this.loc = loc;
        }

        public String getName() {
            return name;
        }

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

        private String name;
        private String loc;
    }
}