Android开发之ImageSwitcher相册功能实例分析

<?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:gravity="center_horizontal">
    <!--定义一个GridView组件-->
    <GridView
      android:id="@+id/grid01"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:listSelector="@null"
      android:numColumns="3"
      android:horizontalSpacing="2dp"
      android:verticalSpacing="2dp"
      android:gravity="center">
    </GridView>
    <!--定义一个ImageSwitcher组件-->
    <ImageSwitcher
      android:id="@+id/switcher"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_gravity="center_horizontal"
      android:padding="50dp"
      android:inAnimation="@android:anim/fade_in"
      android:outAnimation="@android:anim/fade_out"
      android:background="@color/colorPrimaryDark"
      android:visibility="gone">
    </ImageSwitcher>
</RelativeLayout>

public class MainActivity extends Activity {
  int[] imageId = new int[]{
      R.drawable.a0,R.drawable.a1,R.drawable.a2,R.drawable.a4,
      R.drawable.a5,R.drawable.a6,R.drawable.a7,R.drawable.a8,
      R.drawable.a9,R.drawable.a00,R.drawable.a02,R.drawable.a02,
  };
  ImageSwitcher imageSwitcher ;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    //创建一个List对象，list对象的元素是Map
    List<Map<String,Object>> listitems = new ArrayList<Map<String, Object>>();
    for (int i = 0 ; i < imageId.length ; i++ ){
      Map<String,Object> listitem = new HashMap<String, Object>();
      listitem.put("image",imageId[i]);
      listitems.add(listitem);
    }
    //获取显示图片的ImageSwitcher
    imageSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
    //为ImageSwitcher设置动画效果
    imageSwitcher.setFactory(new ViewSwitcher.ViewFactory() {
      @Override
      public View makeView() {
        //创建ImageView对象
        ImageView imageView = new ImageView(MainActivity.this);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setLayoutParams(new ImageSwitcher.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.MATCH_PARENT));
        //返回ImageView对象
        return imageView;
      }
    });
    //创建一个SimpleAdapter
    SimpleAdapter simpleAdapter = new SimpleAdapter(this,listitems,R.layout.cell,new String[]{"image"},new int[]{R.id.image1});
    GridView gridView = (GridView) findViewById(R.id.grid01);
    //为gridView设置adapter
    gridView.setAdapter(simpleAdapter);
    //添加列表选中监听事件
    gridView.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
      @Override
      public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        imageSwitcher.setVisibility(View.VISIBLE);
        imageSwitcher.setClickable(true);
        //显示当前选中图片
        imageSwitcher.setImageResource(imageId[position]);
      }
      @Override
      public void onNothingSelected(AdapterView<?> parent) {
      }
    });
    //添加列表被单击的监听器
    gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
      @Override
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        imageSwitcher.setVisibility(View.VISIBLE);
        imageSwitcher.setClickable(true);
        //显示被单击图片
        imageSwitcher.setImageResource(imageId[position]);
      }
    });
    //为imageSwitcher添加监听事件
    imageSwitcher.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        imageSwitcher.setVisibility(View.GONE);
        imageSwitcher.setClickable(false);
      }
    });
    imageSwitcher.setClickable(false);
  }
}