package com.example.test; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.ViewGroup.LayoutParams; 
import android.view.animation.AnimationUtils; 
import android.widget.Button; 
import android.widget.ImageSwitcher; 
import android.widget.ImageView; 
import android.widget.ViewSwitcher.ViewFactory; 
 
 
public class MainActivity extends Activity{ 
  //声明并初始化一个保存要显示图像id的数组 
  private int[] imageId=new int[]{R.drawable.img01,R.drawable.img02,R.drawable.img03, 
      R.drawable.img04,R.drawable.img05,R.drawable.img06,R.drawable.img07, 
      R.drawable.img08}; 
  private int index=0;//当前显示图像的索引 
  private ImageSwitcher imageSwitcher;//声明一个图像切换器对象 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    imageSwitcher=(ImageSwitcher)findViewById(R.id.imageSwitcher1);//获取图像切换器 
    //设置动画效果 
    imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));//设置淡入动画 
    imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));//设置淡出动画 
    imageSwitcher.setFactory(new ViewFactory() {//设置View工厂 
       
      @Override 
      public View makeView() { 
        ImageView imageView=null; 
        imageView=new ImageView(MainActivity.this);//实例化一个ImageView类的对象 
        imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);//设置保持纵横比居中缩放图像 
        imageView.setLayoutParams(new ImageSwitcher.LayoutParams( 
            LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT)); 
        return imageView; 
      } 
    }); 
    imageSwitcher.setImageResource(imageId[index]);//显示默认的图片 
     
    //“上一张”和“下一张”按钮的控制 
    Button up=(Button)findViewById(R.id.button1); 
    Button down=(Button)findViewById(R.id.button2); 
    up.setOnClickListener(new OnClickListener() { 
       
      @Override 
      public void onClick(View arg0) { 
        if(index>0){ 
          index--;//图片索引后退一个 
        }else{ 
          index=imageId.length-1;//图片达到最前面一张之后，循环至最后一张 
        } 
        imageSwitcher.setImageResource(imageId[index]);//显示当前图片 
      } 
    }); 
    down.setOnClickListener(new OnClickListener() { 
           
          @Override 
          public void onClick(View arg0) { 
            if(index