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>