渐隐渐现切换图片【SwitchImage】

java文件：

package jxaly.yj;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.animation.AnimationUtils;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainImageSwitch extends Activity {
        //当前显示的图片索引
        private int index;
        //图片数组
        private int[] images = { R.drawable.i1, R.drawable.i2, R.drawable.i3};

        /** Called when the activity is first created. */
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            
            //得到ImageSwitcher对象
            final ImageSwitcher is = (ImageSwitcher) findViewById(R.id.is);
            //实现并设置工厂内部接口的makeView方法，用来显示视图。
            is.setFactory(new ViewFactory() {
                @Override
                public View makeView() {
                    return new ImageView(MainImageSwitch.this);
                }
            });
            //设置图片来源
            is.setImageResource(images[index]);
            //设置点击监听器
            is.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //点击会切换图片
                    index++;
                    if (index >= images.length) {
                            index = 0;
                    }
                    is.setImageResource(images[index]);
                }
            });
            //设置切入动画
            is.setInAnimation(AnimationUtils.loadAnimation(getApplicationContext(), android.R.anim.fade_in));
            //设置切出动画
            is.setOutAnimation(AnimationUtils.loadAnimation(getApplicationContext(), android.R.anim.fade_out));
        }
}

main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <TextView android:text="图片翻转" android:gravity="center" 
         android:layout_width="wrap_content" android:layout_height="wrap_content" 
         android:layout_gravity="center"/>
    <ImageSwitcher android:id="@+id/is" android:layout_width="wrap_content" 
         android:layout_height="wrap_content" android:foregroundGravity="center" 
         android:layout_gravity="center" android:layout_marginTop="10dp"></ImageSwitcher>
</LinearLayout>

效果图：