2-6-1 리스트뷰 만들기

MainActivity

package com.example.test;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
 
import java.util.ArrayList;
 
public class MainActivity extends AppCompatActivity {
 
    SingerAdapter adapter;
    EditText nameEdit;
    EditText mobileEdit;
    Button button ;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        ListView listView = (ListView) findViewById(R.id.lv);
        nameEdit = (EditText) findViewById(R.id.name_edit);
        mobileEdit = (EditText) findViewById(R.id.mobile_edit);
        button = (Button) findViewById(R.id.button);
 
        adapter = new SingerAdapter();
 
        adapter.addItem(new SingerItem("장주느", "010-5212-7024", R.drawable.ic_launcher_background));
        adapter.addItem(new SingerItem("장주느1", "010-52024", R.drawable.ic_launcher_background));
        adapter.addItem(new SingerItem("장주느2", "010-51-7024", R.drawable.ic_launcher_background));
        adapter.addItem(new SingerItem("장주느3", "0-5-7024", R.drawable.ic_launcher_background));
        adapter.addItem(new SingerItem("장주4", "010-59-7024", R.drawable.ic_launcher_background));
        adapter.addItem(new SingerItem("장주5", "-52 -7024", R.drawable.ic_launcher_background));
 
 
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                SingerItem item = (SingerItem) adapter.getItem(i);
                Toast.makeText(getApplicationContext(), item.toString(), Toast.LENGTH_LONG).show();
            }
        });
 
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String name = nameEdit.getText().toString();
                String mobile = mobileEdit.getText().toString();
 
                SingerItem item = new SingerItem(name, mobile, R.drawable.ic_launcher_foreground);
 
                adapter.addItem(item);
                adapter.notifyDataSetChanged();
            }
        });
    }
 
    class SingerAdapter extends BaseAdapter
    {
        ArrayList<SingerItem> items = new ArrayList<SingerItem>() ;
 
        public void addItem(SingerItem item)
        {
            items.add(item);
        }
 
        @Override
        public int getCount() {
            return items.size();
        }
 
        @Override
        public Object getItem(int i) {
            return items.get(i);
        }
 
        @Override
        public long getItemId(int i) {
            return i;
        }
 
        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {
            SingerItemView singerItemView = null ;
 
            if(view == null)
            {
                 singerItemView = new SingerItemView(getApplicationContext());
            }
            else
            {
                singerItemView = (SingerItemView) view;
            }
 
            SingerItem item = items.get(i) ;
            singerItemView.setName(item.getName());
            singerItemView.setMobile(item.getMobile());
            singerItemView.setImg(item.getResID());
 
            return singerItemView;
        }
    }
 
}

 

SingerItem

package com.example.test;
 
public class SingerItem {
    private String name ;
    private String mobile ;
    private int resID ;
 
    public SingerItem(String name, String mobile, int resID) {
        this.name = name;
        this.mobile = mobile;
        this.resID = resID ;
    }
 
    public String getName() {
        return name;
    }
 
    public String getMobile() {
        return mobile;
    }
 
    public int getResID()
    {
        return resID ;
    }
 
    @Override
    public String toString() {
        return "SingerItem{" +
                "name='" + name + '\'' +
                ", mobile='" + mobile + '\'' +
                ", resID=" + resID +
                '}';
    }
}
 

 

 

SingerItemView

package com.example.test;
 
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
 
public class SingerItemView extends LinearLayout {
 
    TextView textView;
    TextView textView2;
    ImageView img;
 
    public SingerItemView(Context context) {
        super(context);
 
        init(context);
    }
 
    public SingerItemView(Context context, AttributeSet attrs) {
        super(context, attrs);
 
        init(context);
    }
 
    private void init(Context context)
    {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(R.layout.singer_item_view, this, true);
 
///아래의 방식으로도 인플레이트 할 수 있다.
//View.inflate(getContext() ,R.layout.singer_item_view, this);
 
        textView = findViewById(R.id.tv);
        textView2 = findViewById(R.id.tv2) ;
        img = findViewById(R.id.img) ;
    }
 
    public void setName(String name)
    {
        textView.setText(name);
    }
 
    public void setMobile(String mobile)
    {
        textView2.setText(mobile);
    }
 
    public void setImg(int resID)
    {
        img.setImageResource(resID);
    }
}
 

 

activity_main.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"
    android:orientation="vertical" >
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="false"
        android:orientation="vertical">
 
        <Button
            android:id="@+id/button"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="추가" />
 
        <EditText
            android:id="@+id/name_edit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="이름"
            android:inputType="textPersonName" />
 
        <EditText
            android:id="@+id/mobile_edit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="전화번호"
            android:inputType="textPersonName" />
 
        <ListView
            android:id="@+id/lv"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            />
    </LinearLayout>
</RelativeLayout>

 

singer_item_view.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">
 
    <ImageView
        android:id="@+id/img"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:src="@mipmap/ic_launcher" />
 
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="6dp"
        android:orientation="vertical">
 
        <TextView
            android:id="@+id/tv"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="이름"
            android:textColor="@color/colorPrimaryDark"
            android:textSize="30dp" />
 
        <TextView
            android:id="@+id/tv2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="6dp"
            android:text="전화번호"
            android:textColor="@android:color/holo_orange_dark"
            android:textSize="24dp" />
 
    </LinearLayout>
 
</LinearLayout>

 

 

기본 원리는 리스트뷰에 어댑터를 등록하고 어댑터의 안의

ArrayList<SingerItem> items = new ArrayList<SingerItem>() 로 배열을 선언하고

public View getView(int i, View view, ViewGroup viewGroup)을 등록하여 내가 만든 return singerItemView; 을 리턴하여 아이템 항목을 보여주는 식이다. 

 

singerItemView는 singer_item_view.xml과 연결되어 있다. 

 

아래와 같이 클릭리스너를 등록해 리스트의 몇번째 아이템 항목이 선택되었는지를 알수 있다. 

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override

            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

                SingerItem item = (SingerItem) adapter.getItem(i);

                Toast.makeText(getApplicationContext(), item.toString(), Toast.LENGTH_LONG).show();

            }

        });

 

다음은 버튼을 클릭하여 리스트의 아이템 항목을 추가하는 것인데

  button.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View view) {

                String name = nameEdit.getText().toString();

                String mobile = mobileEdit.getText().toString();

 

                SingerItem item = new SingerItem(name, mobile, R.drawable.ic_launcher_foreground);

 

                adapter.addItem(item);

                adapter.notifyDataSetChanged();

            }

        });

위처럼  adapter.notifyDataSetChanged(); 를 호출하여 어댑터에 변화가 있다고 알려줘야 한다.

 

마지막으로

 public View getView(int i, View view, ViewGroup viewGroup) {

            SingerItemView singerItemView = null ;

 

            if(view == null)

            {

                 singerItemView = new SingerItemView(getApplicationContext());

            }

            else

            {

                singerItemView = (SingerItemView) view;

            }

getView에서 view가 null이 아닐 때 즉 이전에 썼던 객체가 남아있을 때 객체를 더이상 생성하지 않고 재활용하여 객체가 생성되는 수를 줄여 빠르게 만들어 줄 수 있다.

 

결과 화면