ImageSwitcher的功能和用法

先看看继承关系，ImageSwitcher和TextSwitcher的继承关系是一样的。两个重要的父类：ViewSwitcher和ViewAnimator
继承于ViewSwitcher，说明具备了切换功能
继承于ViewAnimator，说明具备了动画功能

重要方法

　　　　setImageURI(Uri uri)：设置图片地址

　　　　setImageResource(int resid)：设置图片资源库

　　　　setImageDrawable(Drawable drawable)：绘制图片

 

实例：

MainActivity.java

public class MainActivity extends Activity {
    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 };

    ImageSwitcher m_imageSwitcher;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // 创建list容器，包含的元素是Map
        List<Map<String, Object>> listMaps = 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]);
            listMaps.add(item);
        }
        m_imageSwitcher = (ImageSwitcher) findViewById(R.id.imageswitcher_id);
        // 为imageSwitcher设置动画效果
        m_imageSwitcher.setFactory(new ViewFactory() {

            @Override
            public View makeView() {
                // 创建ImageView对象
                ImageView image = new ImageView(MainActivity.this);
                image.setScaleType(ImageView.ScaleType.FIT_CENTER);
                image.setLayoutParams(new ImageSwitcher.LayoutParams(
                        LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
                return image;
            }
        });
        // 创建一个simpleAdapter
        SimpleAdapter simpleAdapter = new SimpleAdapter(this, listMaps,
                R.layout.cell, new String[] { "image" },
                new int[] { R.id.image1 });
        GridView gridView = (GridView)findViewById(R.id.gridview_id);
        gridView.setAdapter(simpleAdapter);
        //常见列表被选中的监听器
        gridView.setOnItemSelectedListener(new OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                //显示当前被选中的图片
                m_imageSwitcher.setImageResource(image_ids[position]);                
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
        //添加列表项被单机的监听器
        gridView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                // 显示被单机的列表项
                m_imageSwitcher.setImageResource(image_ids[position]);                
            }
        });
    }

    @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);
    }
}

activity_main.xml

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    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>

cell.xml

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center_horizontal"
    android:padding="4pt"
    >
<ImageView
    android:id="@+id/image1"
    android:layout_width="50dp" 
    android:layout_height="50dp" 
    android:contentDescription="@string/desc_image1"
    />    
</LinearLayout>