그리드 뷰 (GridView)

그리드 뷰 GridView

2차원 격자에 항목들을 표시하는 뷰 그룹

1. 레이아웃

<?xml version="1.0" encoding="utf-8"?>
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gridView01"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="100dp"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:gravity="center">
</GridView>

2. 이미지 어댑터를 처리하는 클래스

자바 파일을 만들고 어댑터 기능을 수행하게 하려면 BaseAdapter를 extends하고,

빨간 줄이 뜨면 그 위에서 Alt+Enter를 누르면 필요한 메서드들이 오버라이딩 된다.

package com.progdv.app05_gridview;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter{
    Context context;

    private Integer[] mThumblds ={R.drawable.ph1_s, R.drawable.ph2_s, R.drawable.ph3_s,
            R.drawable.ph4_s, R.drawable.ph5_s, R.drawable.ph6_s,
            R.drawable.ph1_s, R.drawable.ph2_s, R.drawable.ph3_s,
            R.drawable.ph4_s, R.drawable.ph5_s, R.drawable.ph6_s,
            R.drawable.ph1_s, R.drawable.ph2_s, R.drawable.ph3_s,
            R.drawable.ph4_s, R.drawable.ph5_s, R.drawable.ph6_s,
            R.drawable.ph1_s, R.drawable.ph2_s, R.drawable.ph3_s,
            R.drawable.ph4_s, R.drawable.ph5_s, R.drawable.ph6_s
    };

    public ImageAdapter(Context context){
        this.context = context;
    }

    @Override
    public int getCount() {
        return mThumblds.length;
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView imageView;

        if(convertView == null){
            imageView = new ImageView(context);
            imageView.setLayoutParams(new GridView.LayoutParams(300,300));
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        }else{
            imageView = (ImageView) convertView;
        }

        imageView.setImageResource(mThumblds[position]);
        return imageView;
    }
}

3. 메인 클래스

package com.progdv.app05_gridview;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    GridView gridView;

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

        // 그리드 어댑터 세팅: 이미지 처리를 위한 이미지 어댑터를 그리드뷰에 전달
        gridView = (GridView)findViewById(R.id.gridView01);
        ImageAdapter imageAdapter = new ImageAdapter(this);
        gridView.setAdapter(imageAdapter);

        // 이벤트 처리를 위한 부분
        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Toast.makeText(getApplicationContext(), (++position)+"번째 이미지 선택", Toast.LENGTH_SHORT).show();
            }
        });
    }
}