android使用ViewPager实现轮播效果

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android" > 
 <item android:state_enabled="true"> 
  <shape android:shape="oval"> 
   <size android:width="5dp" android:height="5dp"/> 
   <solid android:color="#fff"/> 
  </shape> 
 </item> 
  <item android:state_enabled="false"> 
  <shape android:shape="oval"> 
   <size android:width="5dp" android:height="5dp"/> 
   <solid android:color="#8ee5ee"/> 
  </shape> 
 </item> 
 
</selector> 

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 tools:context=".mainactivity" > 
 
 <listview 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:id="@+id/lv_list" /> 
</relativelayout> 

<framelayout xmlns:android="http://schemas.android.com/apk/res/android" 
 xmlns:tools="http://schemas.android.com/tools" 
 android:layout_width="match_parent" 
 android:layout_height="match_parent" 
 tools:context=".mainactivity" > 
 
 <android.support.v4.view.viewpager 
  android:id="@+id/vp_image" 
  android:layout_width="wrap_content" 
  android:layout_height="150dp" 
  android:layout_gravity="center" /> 
 <linearlayout 
  android:layout_width="match_parent" 
  android:layout_height="40dp" 
  android:id="@+id/layout" 
  android:layout_gravity="bottom" 
  android:gravity="center" 
  android:orientation="horizontal" 
  ></linearlayout> 
</framelayout> 

package cn.edu.huse.banner_re.util; 
import android.graphics.bitmap; 
import android.graphics.bitmapfactory; 
import android.os.asynctask; 
import java.io.ioexception; 
import java.io.inputstream; 
import java.net.httpurlconnection; 
import java.net.malformedurlexception; 
import java.net.url; 
 
/** 
 * 图片加载的工具类 
 * @author xray 
 * 
 */ 
public class imageloader { 
 
 /** 
  * 图片加载完成的回调接口 
  * 添加url参数，用于做图片错位判断 
  */ 
 public interface onimageloadlistener{ 
  //完成图片加载 
  void onimageloadcomplete(string url, bitmap bitmap); 
 } 
  
 private onimageloadlistener mlistener; 
  
 /** 
  * 启动图片加载任务 
  * @param urlstr 
  * @param listener 
  */ 
 public void loadimage(string urlstr,onimageloadlistener listener){ 
  this.mlistener = listener; 
  new imageloadtask().execute(urlstr); 
 } 
  
 /** 
  * 图片加载任务 
  * @author xray 
  * 
  */ 
 class imageloadtask extends asynctask<string,void,imageloadtask.urlandbitmap>{ 
   
  @override 
  protected urlandbitmap doinbackground(string... params) { 
    
   try { 
    //创建url，指定图片地址 
    url url = new url(params[0]); 
    //打开连接获得httpurlconnection对象 
    httpurlconnection conn = (httpurlconnection) url.openconnection(); 
    //获得文件输入流 
    inputstream stream = conn.getinputstream(); 
    //把输入流转换为图片 
    bitmap bmp = bitmapfactory.decodestream(stream); 
    //关闭流 
    stream.close(); 
    return new urlandbitmap(params[0],bmp); 
   } catch (malformedurlexception e) { 
    e.printstacktrace(); 
   } catch (ioexception e) { 
    e.printstacktrace(); 
   } 
   return null; 
  } 
 
  //包装图片地址和图片 
  class urlandbitmap{ 
   string url; 
   bitmap bitmap; 
   public urlandbitmap(string url, bitmap bitmap) { 
    this.url = url; 
    this.bitmap = bitmap; 
   } 
  } 
   
  @override 
  protected void onpostexecute(urlandbitmap result) { 
   //进行接口回调 
   if(mlistener != null){ 
    mlistener.onimageloadcomplete(result.url,result.bitmap); 
   } 
  } 
 } 
} 

package cn.edu.huse.banner_re.util; 
 
import android.os.asynctask; 
 
import java.io.ioexception; 
import java.io.inputstream; 
import java.net.httpurlconnection; 
import java.net.malformedurlexception; 
import java.net.url; 
 
/** 
 * 读取服务器json的工具类 
 * @author xray 
 * 
 */ 
public class jsonloader { 
  
 public interface onjsonloadlistener{ 
  void onjsonloadcomplete(string json); 
 } 
  
 private onjsonloadlistener mlistener; 
  
 public void loadjson(string urlstr,onjsonloadlistener listener){ 
  this.mlistener = listener; 
  new jsonloadtask().execute(urlstr); 
 } 
  
 class jsonloadtask extends asynctask<string,void,string>{ 
 
  @override 
  protected string doinbackground(string... params) { 
   try { 
    url url = new url(params[0]); 
    httpurlconnection conn = (httpurlconnection) url.openconnection(); 
    inputstream inputstream = conn.getinputstream(); 
    byte[] buffer = new byte[1024]; 
    int len = 0; 
    //stringbuffer 线程安全，性能低 vs stringbuilder 线程不安全，性能高 
    stringbuilder strb = new stringbuilder(); 
    while((len = inputstream.read(buffer)) != -1){ 
     //将字节码转换为string 
     string str = new string(buffer,0,len); 
     strb.append(str); 
    } 
    inputstream.close(); 
    return strb.tostring(); 
   } catch (malformedurlexception e) { 
    e.printstacktrace(); 
   } catch (ioexception e) { 
    e.printstacktrace(); 
   } 
   return null; 
  } 
 
  @override 
  protected void onpostexecute(string result) { 
   if(mlistener != null){ 
    mlistener.onjsonloadcomplete(result); 
   } 
  }  
 } 
} 

package cn.edu.huse.banner_re.adapter; 
 
import java.util.list; 
 
import android.support.v4.view.pageradapter; 
import android.view.view; 
import android.view.viewgroup; 
import android.widget.imageview; 
 
/** 
 * 图片轮播的适配器 
 * @author lenovo 
 * 
 */ 
public class myviewpageradapter extends pageradapter { 
 
 private list<imageview> mdata; 
  
 public myviewpageradapter(list<imageview> mdata) { 
  this.mdata = mdata; 
 } 
 //返回视图的数量 
 @override 
 public int getcount() { 
  return mdata.size(); 
 } 
  
 @override 
 public boolean isviewfromobject(view arg0, object arg1) { 
  return arg0 == arg1; 
 } 
 
 //销毁图片 
 @override 
 public void destroyitem(viewgroup container, int position, object object) { 
  container.removeview(mdata.get(position)); 
 } 
  
 //添加图片 
 @override 
 public object instantiateitem(viewgroup container, int position) { 
  container.addview(mdata.get(position)); 
  return mdata.get(position); 
 } 
  
} 

package cn.edu.huse.banner_re; 
 
import java.util.arraylist; 
import java.util.list; 
 
import org.json.jsonarray; 
import org.json.jsonobject; 
 
import android.app.activity; 
import android.graphics.bitmap; 
import android.os.bundle; 
import android.os.handler; 
import android.support.v4.view.viewpager; 
import android.support.v4.view.viewpager.onpagechangelistener; 
import android.view.layoutinflater; 
import android.view.view; 
import android.view.view.onclicklistener; 
import android.widget.arrayadapter; 
import android.widget.imageview; 
import android.widget.linearlayout; 
import android.widget.listview; 
import android.widget.radiobutton; 
import cn.edu.huse.banner_re.adapter.myviewpageradapter; 
import cn.edu.huse.banner_re.util.imageloader; 
import cn.edu.huse.banner_re.util.imageloader.onimageloadlistener; 
import cn.edu.huse.banner_re.util.jsonloader; 
import cn.edu.huse.banner_re.util.jsonloader.onjsonloadlistener; 
 
public class mainactivity extends activity implements onclicklistener{ 
 
 public static final string url_gift = "http://www.1688wan.com/majax.action?method=getgiftlist&pageno=1"; 
 public static final string url_base = "http://www.1688wan.com"; 
 private listview mlv; 
 //放置圆点图片的布局 
 private linearlayout mlayout; 
 private viewpager mpager; 
 //保存viewpager上图片的集合 
 private list<imageview> mimageviews; 
 //保存圆点图片的集合 
 private list<imageview> mdotviews; 
 //当前图片 
 private imageview mdotview; 
 //当前下标 
 private int mindex; 
 private handler mhandler = new handler(); 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  setcontentview(r.layout.activity_main); 
  //初始化viewpager 
  initviewpager(); 
 } 
 
 private void initviewpager() { 
  new jsonloader().loadjson(url_gift, new onjsonloadlistener() { 
   @override 
   public void onjsonloadcomplete(string json) { 
    //得到图片的地址 
    list<string> list = josnpare(json); 
    //初始化主控件 
    initview(); 
    //将图片显示到viewpager中 
    initimageviews(list); 
    //为viewpager设置适配器 
    mpager.setadapter(new myviewpageradapter(mimageviews)); 
    //加载圆点图片 
    initdot(mimageviews.size()); 
    //实现图片的轮播 
    mpager.postdelayed(new runnable() { 
     @override 
     public void run() { 
      //下标自动++ 
      mindex++; 
      //当下标到最后时，就重新来过 
      if(mindex >= mimageviews.size()){ 
       mindex = 0; 
      } 
      //设置图片 
      mpager.setcurrentitem(mindex); 
      //重复调用 
      mhandler.postdelayed(this, 1500); 
     } 
    }, 1500); 
    //添加页码滑动的监听，实现圆点图片的切换 
    mpager.setonpagechangelistener(new onpagechangelistener() { 
      
     //页选中后调用 
     @override 
     public void onpageselected(int arg0) { 
      //改变原来的圆点图片的状态 
      mdotview.setenabled(true); 
      //更新当前的圆点图片 
      mdotview = mdotviews.get(arg0); 
      //将当前选中的圆点设为选中状态 
      mdotview.setenabled(false); 
      //更新下标 
      mindex = arg0; 
     } 
      //滑动中途调用 
     @override 
     public void onpagescrolled(int arg0, float arg1, int arg2) { 
       
     } 
      //页面滑动状态修改 
     @override 
     public void onpagescrollstatechanged(int arg0) { 
       
     } 
    }); 
   } 
  }); 
 } 
  
 /**获取圆点图片函数 
  * @param count viewpager上图片的数量 
  */ 
 private void initdot(int count){ 
  mdotviews = new arraylist<imageview>(); 
  linearlayout.layoutparams params = new linearlayout.layoutparams( 
    linearlayout.layoutparams.wrap_content, 
    linearlayout.layoutparams.wrap_content); 
  //设置边距 
  params.setmargins(5, 0, 5, 0); 
  for(int i = 0; i < count; i++){ 
   imageview image = new imageview(this); 
   //设置圆点图片 
   image.setimageresource(r.drawable.mydot); 
   //设置图片的位置，方便后面的取值 
   image.settag(i); 
   //设置监听 
   image.setonclicklistener(this); 
   //添加到布局中 
   mlayout.addview(image, params); 
   //将圆点图片保存到集合中 
   mdotviews.add(image); 
  } 
  mdotview = mdotviews.get(0); 
  mdotview.setenabled(false); 
 } 
  
 /** 
  *显示图片的函数 
  */ 
 private void initimageviews(list<string> list) { 
  mimageviews = new arraylist<imageview>(); 
  for(string str : list){ 
   final imageview imageview = new imageview(this); 
   //设置默认图片 
   imageview.setimageresource(r.drawable.ic_launcher); 
   new imageloader().loadimage(url_base+str, new onimageloadlistener() { 
     
    @override 
    public void onimageloadcomplete(string url, bitmap bitmap) { 
     if(bitmap != null){ 
      imageview.setimagebitmap(bitmap); 
     } 
    } 
   }); 
   //将imageview保存到集合中 
   mimageviews.add(imageview); 
  } 
   
 } 
 /** 
  * json解析获取图片的地址 
  * @param url 
  * @return 
  */ 
 private list<string> josnpare(string url){ 
  list<string> list = new arraylist<string>(); 
  try { 
   jsonobject jobj = new jsonobject(url); 
   jsonarray array = jobj.getjsonarray("ad"); 
   for(int i = 0; i < array.length(); i++){ 
    jsonobject obj = (jsonobject) array.get(i); 
    list.add(obj.getstring("iconurl")); 
   } 
  } catch (exception e) { 
   e.printstacktrace(); 
  } 
  return list; 
 } 
  
 /** 
  * 初始化控件 
  */ 
 private void initview() { 
  //找到控件 
  mlv = (listview) findviewbyid(r.id.lv_list); 
   
  view view = layoutinflater.from(this).inflate(r.layout.activity_banner, null); 
  mpager = (viewpager)view.findviewbyid(r.id.vp_image); 
  //圆点图片布局 
  mlayout = (linearlayout)view.findviewbyid(r.id.layout); 
  //模拟数据 
  list<string> mlist = new arraylist<string>(); 
  for(int i = 0; i < 20; i++){ 
   mlist.add("条目--"+i); 
  } 
  //创建适配器 
  arrayadapter<string> madapter = new arrayadapter<string>(this, 
    android.r.layout.simple_list_item_1, 
    android.r.id.text1, 
    mlist); 
  //设置头部视图 
  mlv.addheaderview(view); 
  //设置适配器 
  mlv.setadapter(madapter); 
  /*//圆点图片布局 
  mlayout = (linearlayout)findviewbyid(r.id.layout);*/ 
 } 
  
  
 /** 
  * 圆点图片的监听事件 
  */ 
 @override 
 public void onclick(view arg0) { 
  //获取该圆点图片的位置 
  int index = integer.parseint(arg0.gettag().tostring()); 
  //将viewpager的图片显示成下标为index的图片 
  mpager.setcurrentitem(index); 
  //将原来的设置成默认值 
  mdotview.setenabled(true); 
  //保存新的值 
  mdotview = (imageview) arg0; 
  //将新的值改变成false 
  mdotview.setenabled(false); 
  //更新下标 
  mindex = index; 
 } 
 
}