GridView组件的使用

• 新建一个HelloGridView的工程
• 修改main.xml代码如下：

　　

<?xml version="1.0" encoding="utf-8"?>
<GridView
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/gridview"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:columnWidth="90dp"
  android:numColumns="auto_fit"
  android:horizontalSpacing="10dp"
  android:verticalSpacing="10dp"
  android:stretchMode="columnWidth"
  android:gravity="center">
</GridView>

 很简单，就是一个GridView。设置列宽为90dp,这样当我们的numColumns设置为auto_fit时，Android就会自动计算我们手机屏幕的大小以决定每一行展示几个元素。这是很方便。android:horizontalSpacing定义列之间的间隔，android:verticalSpacing定义行之间的间隔。android:stretchMode设置为columnWidth是意味着根据列宽自动缩放。

• 修改我们Activity HelloGridView如下：

　　

/**
 * 
 * @author 飞雪无情
 * @since 2011-1-20
 */
public class HelloGridView extends Activity {
    /** Called when the activity is first created. */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        GridView gridView=(GridView)findViewById(R.id.gridview);
        gridView.setAdapter(new ImageAdapter(this));
        //单击GridView元素的响应
        gridView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                //弹出单击的GridView元素的位置
                Toast.makeText(HelloGridView.this,mThumbIds[position], Toast.LENGTH_SHORT).show();
            }
        });
    }
    private class ImageAdapter extends BaseAdapter{
        private Context mContext;

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

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

        @Override
        public Object getItem(int position) {
            return mThumbIds[position];
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            //定义一个ImageView,显示在GridView里
            ImageView imageView;
            if(convertView==null){
                imageView=new ImageView(mContext);
                imageView.setLayoutParams(new GridView.LayoutParams(85, 85));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(8, 8, 8, 8);
            }else{
                imageView = (ImageView) convertView;
            }
            imageView.setImageResource(mThumbIds[position]);
            return imageView;
        }
        

        
    }
    //展示图片
    private Integer[] mThumbIds = {
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7,
            R.drawable.sample_0, R.drawable.sample_1,
            R.drawable.sample_2, R.drawable.sample_3,
            R.drawable.sample_4, R.drawable.sample_5,
            R.drawable.sample_6, R.drawable.sample_7
    };
}

这里我们也是采用的自定义Adapter，可以上一节的自定义Adapter讲解。展示了一些图片，然后点击一个图片的时候会显示这个图片所在的位置。

运行程序，效果图如下：