ImageSwitcher图像切换器的使用实例

package com.example.imageswitchdemo;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity
{
  TextView show=null;
  Button up,dowm=null;
  ImageSwitcher image=null;
  private int[] images=new int[]{R.drawable.a001,R.drawable.a002,R.drawable.a003,
                  R.drawable.a004,R.drawable.a005,R.drawable.a006,
                  R.drawable.a007,R.drawable.a008,R.drawable.a009};
  private int index=0;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //获取控件
    show=(TextView) findViewById(R.id.show);
    up=(Button) findViewById(R.id.up);
    dowm=(Button) findViewById(R.id.down);
    image=(ImageSwitcher) findViewById(R.id.image);

    //为获取到的控件添加显示效果:淡入动画和淡出动画
    image.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
    image.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));

    //为图像切换器设置一个ViewFactory，并重写makeView方法
    image.setFactory(new ViewFactory()
    {

      @Override
      public View makeView()
      {
        //指定视图切换工程
        return new ImageView(MainActivity.this);
      }
    });
    image.setImageResource(images[index]);
    show.setText("一共有"+images.length+"张图片，当前是第"+(index+1)+"张图片");

    //当点击按钮时，图像切换并显示相应的信息
    up.setOnClickListener(new OnClickListener()
    {

      @Override
      public void onClick(View arg0)
      {
        if(index>0)
          index--;
        else
          index=images.length-1;

        image.setImageResource(images[index]);
        show.setText("一共有"+images.length+"张图片，当前是第"+(index+1)+"张图片");
      }
    });

    //同理，当点击按钮时，图像切换并显示相应的信息
    dowm.setOnClickListener(new OnClickListener()
    {
      public void onClick(View arg0)
      {
        if(index