Android实现图片浏览器示例

package com.android.coding;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.Gallery.LayoutParams;
import android.widget.ViewSwitcher.ViewFactory;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
public class ViewPicturesActivity extends Activity {
 ImageSwitcher imageSwitcher; //声明ImageSwitcher对象，图片显示区域
 Gallery gallery;       //声明Gallery对象，图片列表索引
 int imagePosition;      //标记图片数组下标，用于循环显示
 //声明图片整型数组
 private int[] images = {
  R.drawable.image1,R.drawable.image2,
  R.drawable.image3,R.drawable.image4,
  R.drawable.image5,R.drawable.image6,
  R.drawable.image7,R.drawable.image8,
  R.drawable.image9,R.drawable.image10,
  R.drawable.image11,R.drawable.image12,
  R.drawable.image13,R.drawable.image14,
  R.drawable.image15,R.drawable.image16,
  R.drawable.image17};
 
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    //通过控件的ID获得imageSwitcher的对象
    imageSwitcher = (ImageSwitcher) findViewById(R.id.switcher);
    //设置自定义的图片显示工厂类
    imageSwitcher.setFactory(new MyViewFactory(this));
    //通过控件的ID获得gallery的对象
    gallery = (Gallery) findViewById(R.id.gallery);
    //设置自定义的图片适配器
    gallery.setAdapter(new ImageAdapter(this)); 
    //实现被选中的事件监听器
    gallery.setOnItemSelectedListener(new OnItemSelectedListener() {        
  @Override
  public void onItemSelected(AdapterView<?> parent, View view,
   int position, long id) {
  //通过求余数，循环显示图片
  imageSwitcher.setImageResource(images[position%images.length]);  
  }
  @Override
  public void onNothingSelected(AdapterView<?> parent) {
  // TODO Auto-generated method stub  
  }
 });    
  }
  
  //自定义图片适配器，继承BaseAdapter
  class ImageAdapter extends BaseAdapter{   
 private Context context; //定义上下文
 
 //参数为上下文的构造方法
 public ImageAdapter(Context context) {
  this.context = context;
 }
   
 //得到图片的大小
 @Override
 public int getCount() {  //设置为整型的最大数
  return Integer.MAX_VALUE;
 }

 //得到指定图片的对象
 @Override
 public Object getItem(int position) {  
  return null;
 }
 
 //得到指定图片的对象的ID
 @Override
 public long getItemId(int position) {  
  return 0;
 }

 //显示图标列表
 @Override
 public View getView(int position, View convertView, ViewGroup parent) {
  ImageView iv = new ImageView(context); //创建ImageView对象
  iv.setImageResource(images[position%images.length]);  //设置循环显示图片
  iv.setAdjustViewBounds(true); //图片自动调整显示
  //设置图片的宽和高
  iv.setLayoutParams(new Gallery.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
  return iv; //返回ImageView对象
 }   
  }
  
  //自定义图片显示工厂类，继承ViewFactory
  class MyViewFactory implements ViewFactory{
 private Context context; //定义上下文
 
 //参数为上下文的构造方法
 public MyViewFactory(Context context) {
  this.context = context;
 }

 //显示图标区域
   @Override
 public View makeView() {
  ImageView iv = new ImageView(context); //创建ImageView对象
  iv.setScaleType(ImageView.ScaleType.FIT_CENTER); //图片自动居中显示
  //设置图片的宽和高
  iv.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
  return iv; //返回ImageView对象
 }   
  }  
}