Android实现仿Windows7图片预览窗格效果

package com.example.test; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.ViewGroup; 
import android.view.ViewGroup.LayoutParams; 
import android.view.animation.AnimationUtils; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.BaseAdapter; 
import android.widget.GridView; 
import android.widget.ImageSwitcher; 
import android.widget.ImageView; 
import android.widget.ViewSwitcher.ViewFactory; 
 
public class MainActivity extends Activity { 
 private int[] imageId=new int []{R.drawable.img1,R.drawable.img2,R.drawable.img3,R.drawable.img4, 
   R.drawable.img5,R.drawable.img6,R.drawable.img7,R.drawable.img8,R.drawable.img9}; 
 private ImageSwitcher imageSwitcher; 
 @Override 
 public 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() { 
    
   @Override 
   public View makeView() { 
    //实例化一个ImageView对象 
    ImageView imageView=new ImageView(MainActivity.this); 
    //设置保持纵横比居中缩放图像 
    imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); 
    imageView.setLayoutParams(new ImageSwitcher.LayoutParams( 
      LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT)); 
    return imageView;//返回imageView对象 
   } 
  }); 
  imageSwitcher.setImageResource(R.drawable.img3);//设置默认显示的图像 
   
   
  GridView gridview=(GridView)findViewById(R.id.gridView1); 
  BaseAdapter adapter=new BaseAdapter(){ 
 
 
   @Override 
   public View getView(int position, View convertView, ViewGroup parent) { 
    ImageView imageView = null;//声明一个ImageView对象 
    if(convertView==null){ 
     imageView=new ImageView(MainActivity.this);//实例化ImageView对象 
     /****************设置图像的宽度和高度*******************/ 
     imageView.setAdjustViewBounds(true); 
     imageView.setMaxWidth(150); 
     imageView.setMaxHeight(113); 
     /*********************************************************/ 
     imageView.setPadding(5, 5, 5, 5); 
    }else{ 
     imageView=(ImageView)convertView; 
    } 
    imageView.setImageResource(imageId[position]); 
    return imageView; 
   } 
    
   //功能:获得当前选项的id 
   @Override 
   public long getItemId(int position) { 
    return position; 
   } 
    
   //功能：获得当前选项 
   @Override 
   public Object getItem(int position) { 
    return position; 
   } 
    
   //获得数量 
   @Override 
   public int getCount() { 
    return imageId.length; 
   } 
  }; 
  gridview.setAdapter(adapter); 
  gridview.setOnItemClickListener(new OnItemClickListener() { 
 
 
   @Override 
   public void onItemClick(AdapterView parent, View view, int position, 
     long id) { 
     //显示选中的照片 
     imageSwitcher.setImageResource(imageId[position]); 
   } 
  }); 
 } 
}