GridView的功能和用法

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

    <ImageView
        android:id="@+id/image1"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:contentDescription="@string/str_datu" />

</LinearLayout>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    tools:context="com.crazy.gridview.MainActivity" >

    <GridView
        android:id="@+id/grid01"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:horizontalSpacing="1pt"
        android:numColumns="4"
        android:verticalSpacing="1pt" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="240dp"
        android:layout_height="240dp"
        android:layout_gravity="center_horizontal"
        android:contentDescription="@string/string_yulan" />

</LinearLayout>

public class MainActivity extends Activity {

    GridView m_gridView;
    ImageView m_imageView;
    int[] image_ids = new int[] { R.drawable.focus_1, R.drawable.focus_2,
            R.drawable.focus_3, R.drawable.focus_4, R.drawable.focus_5,
            R.drawable.focus_7, R.drawable.focus_8, R.drawable.focus_9,
            R.drawable.focus_10, R.drawable.focus_11, R.drawable.focus_12,
            R.drawable.focus_13, R.drawable.focus_14, R.drawable.focus_15,
            R.drawable.focus_16 };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 创建list对象，存放的是map
        List<Map<String, Object>> listItems = new ArrayList<Map<String, Object>>();
        for (int i = 0; i < image_ids.length; i++) {
            Map<String, Object> item = new HashMap<String, Object>();
            item.put("image", image_ids[i]);
            listItems.add(item);
        }

        // 获取显示图片的imageview
        m_imageView = (ImageView) findViewById(R.id.imageView);

        // 创建一个SimpleAdapter
        SimpleAdapter simpleAdapter = new SimpleAdapter(this, listItems,
                R.layout.cell, new String[] { "image" },
                new int[] { R.id.image1 });
        m_gridView = (GridView) findViewById(R.id.grid01);
        m_gridView.setAdapter(simpleAdapter);
        m_gridView.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                    long arg3) {
                // TODO Auto-generated method stub
                m_imageView.setImageResource(image_ids[arg2]);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}