ImageSwitcher (图像切换器，显示图片)

ImageSwitcher继承了ViewSwitcher，主要在切换图片时加入动画效果

使用方法：

　　　　1.为ImageSwitcher提供一个ViewFactory,该ViewFactory生成的View组件必须是ImageView

　　　　2.切换图片时，用到的3个方法：imageSwitcher.setImageDrawable(Drawable drawable);

　　　　　　　　　　　　　　　　　　  imageSwitcher.setImageResource(int resid);

　　　　　　　　　　　　　　　　　　  imageSwitcher.setImageURI(URI uri);

---

1.java代码：

 package gdp.switcherview2;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

 import android.app.Activity;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.View;
 import android.view.ViewGroup.LayoutParams;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemClickListener;
 import android.widget.AdapterView.OnItemSelectedListener;
 import android.widget.GridView;
 import android.widget.ImageSwitcher;
 import android.widget.ImageView;
 import android.widget.SimpleAdapter;
 import android.widget.Toast;
 import android.widget.ViewSwitcher.ViewFactory;

 public class MainActivity extends Activity {
     //声明一个数组，用来装载图片资源
     int[] imageIds = new int[]{R.drawable.baiyang, R.drawable.chunv, R.drawable.jinniu, R.drawable.juxie,
                             R.drawable.mojie, R.drawable.sheshou, R.drawable.shizi, R.drawable.shuangyu,
                             R.drawable.shuangzi, R.drawable.shuiping, R.drawable.tiancheng, R.drawable.tianxie};
     //声明ImageSwitcher对象
     private ImageSwitcher switcher ;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);

         //创建一个List对象，其元素Map
         List<Map<String, Object>> listItems = new ArrayList<Map<String,Object>>();
         for(int i = 0; i<imageIds.length; i++){
             Map<String, Object> listItem = new HashMap<String, Object>();
             listItem.put("image", imageIds[i]);
             listItems.add(listItem);
         }

         //获取显示图片的ImageSwitcher
         switcher = (ImageSwitcher)findViewById(R.id.switcher);
         //为imageSwicher设置图片切换的动画效果
         switcher.setFactory(new ViewFactory() {

             @Override
             public View makeView() {
                 // 创建imageView对象
                 ImageView imageView = new ImageView(MainActivity.this);
                 imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                 imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.WRAP_CONTENT,
                                         LayoutParams.WRAP_CONTENT));
                 //返回ImageView对象
                 return imageView;
             }
         });
         //创建Adapter
         SimpleAdapter simpleAdapter = new SimpleAdapter(this, listItems, R.layout.cell, new String[]{"image"}, new int[]{R.id.image1});
         GridView grid = (GridView)findViewById(R.id.grid01);
         grid.setAdapter(simpleAdapter);
         //添加列表项被点击的监听器
         grid.setOnItemClickListener(new ItemClick());
         //添加列表项被选中的监听器
         grid.setOnItemSelectedListener(new ItemSelect());
     }

     class ItemClick implements OnItemClickListener{

         @Override
         public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                 long arg3) {
             // TODO Auto-generated method stub
             switcher.setImageResource(imageIds[arg2]);
         }

     }

     class ItemSelect implements OnItemSelectedListener{

         @Override
         public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
                 long arg3) {
             // TODO Auto-generated method stub
             switcher.setImageResource(imageIds[arg2]);
         }

         @Override
         public void onNothingSelected(AdapterView<?> arg0) {
             // TODO Auto-generated method stub
             Toast.makeText(MainActivity.this, "Nothing Selected" , Toast.LENGTH_LONG).show();
         }

     }

     @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;
     }

 }

2.xml文件

main.xml

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:orientation="vertical"
     android:gravity="center_horizontal" >
     <!-- 定义一个GridView组件 -->
     <GridView
         android:id="@+id/grid01"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:horizontalSpacing="2dp"
         android:verticalSpacing="2dp"
         android:numColumns="4"
         android:gravity="center"
         />
     <!-- 定义一个ImageSwitcher组件 -->
     <ImageSwitcher
         android:id="@+id/switcher"
         android:layout_width="300dp"
         android:layout_height="300dp"
         android:layout_gravity="center_horizontal"
         android:inAnimation="@android:anim/fade_in"
         android:outAnimation="@android:anim/fade_out"
         />
 </LinearLayout>

cell.xml

 <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="fill_parent"
         android:layout_height="fill_parent"
         android:scaleType="fitXY"
         />
 </LinearLayout>