Android ViewPager实现图片轮翻效果

很多app都有这种效果，特别一些电商类的app，顶部每隔几秒钟会向右翻页显示下张图片，用来作推广或者内容展示用的。今天来简单地模仿一下，还自带一个自动跳动的小功能（底部有几个小点，图片移动的时候，点的状态也在变化），用定时器来实现不难。

import java.util.arraylist; 
import java.util.list; 
 
import android.app.activity; 
import android.os.bundle; 
import android.os.handler; 
import android.os.message; 
import android.os.systemclock; 
import android.support.v4.view.pageradapter; 
import android.support.v4.view.viewpager; 
import android.support.v4.view.viewpager.onpagechangelistener; 
import android.util.log; 
import android.view.view; 
import android.view.viewgroup; 
import android.widget.imageview; 
import android.widget.linearlayout; 
import android.widget.linearlayout.layoutparams; 
import android.widget.textview; 
 
public class mainactivity extends activity implements onpagechangelistener { 
  
 protected static final string tag = "mainactivity"; 
 private list<imageview> imageviewlist; 
 private viewpager mviewpager; 
 private final int[] imageresids = { 
   r.drawable.a, 
   r.drawable.b, 
   r.drawable.c, 
   r.drawable.d, 
   r.drawable.e 
 }; 
 private final string[] imagedescriptions = { 
   "巩俐不低俗，我就不能低俗", 
   "扑树又回来啦！再唱经典老歌引万人大合唱", 
   "揭秘北京电影如何升级", 
   "乐视网tv版大派送", 
   "热血屌丝的反杀" 
 }; 
 private textview tvimagedescription; // 图片描述 
 private linearlayout llpointgroup;  // 点控件的组 
 private int previousposition = 0;  // viewpager选中的前一个position 
 private boolean isstop = false; // 控制循环的子线程是否停止 
  
 private handler handler = new handler(){ 
 
  @override 
  public void handlemessage(message msg) { 
   super.handlemessage(msg); 
    
   mviewpager.setcurrentitem(mviewpager.getcurrentitem() + 1); 
  } 
 }; 
 
 @override 
 protected void oncreate(bundle savedinstancestate) { 
  super.oncreate(savedinstancestate); 
  setcontentview(r.layout.activity_main); 
   
  initview(); 
   
  new thread(new runnable() { 
 
   @override 
   public void run() { 
    // 每两秒钟向主线程发送一条消息, 切换viewpager的界面 
    while(!isstop) { 
     systemclock.sleep(2000); 
      
     handler.sendemptymessage(0); 
    } 
    log.i(tag, "循环线程停止了"); 
   }}).start(); 
 } 
  
 @override 
 protected void ondestroy() { 
  isstop = true; 
  super.ondestroy(); 
 } 
 
 private void initview() { 
  mviewpager = (viewpager) findviewbyid(r.id.viewpager); 
  llpointgroup = (linearlayout) findviewbyid(r.id.ll_point_group); 
  tvimagedescription = (textview) findviewbyid(r.id.tv_image_description); 
   
  imageviewlist = new arraylist<imageview>(); 
   
  imageview iv; 
  view pointview; 
  layoutparams params; 
  for (int i = 0; i < imageresids.length; i++) { 
   iv = new imageview(this); 
   iv.setbackgroundresource(imageresids[i]); 
   imageviewlist.add(iv); 
    
   // 根据图片添加点 
   pointview = new view(this); 
   params = new layoutparams(5, 5); 
   params.leftmargin = 5; 
   pointview.setlayoutparams(params); 
   pointview.setenabled(false); 
   pointview.setbackgroundresource(r.drawable.point_bg); 
   llpointgroup.addview(pointview); 
  } 
   
  mypageradapter madapter = new mypageradapter(); 
  mviewpager.setadapter(madapter); 
  mviewpager.setonpagechangelistener(this); 
   
  int item = (integer.max_value / 2) - ((integer.max_value / 2) % imageviewlist.size()); 
  mviewpager.setcurrentitem(item);  // 设置当前选中的item的position 
   
  tvimagedescription.settext(imagedescriptions[previousposition]); 
  llpointgroup.getchildat(previousposition).setenabled(true); // 第一点被选中 
 } 
  
  
 class mypageradapter extends pageradapter { 
 
  @override 
  public int getcount() { 
   return integer.max_value; 
  } 
 
  /** 
   * 移动的对象和进来的对象如果是同一个就返回true, 代表复用view对象 
   * false 使用object对象 
   */ 
  @override 
  public boolean isviewfromobject(view arg0, object arg1) { 
   return arg0 == arg1; 
  } 
 
  /** 
   * 需要销毁的对象的position传进来 
   */ 
  @override 
  public void destroyitem(viewgroup container, int position, object object) { 
   // 移除掉指定position的对象 
   mviewpager.removeview(imageviewlist.get(position % imageviewlist.size())); 
  } 
 
  /** 
   * 加载position位置的view对象 
   */ 
  @override 
  public object instantiateitem(viewgroup container, int position) { 
   // 添加指定position的对象 
   mviewpager.addview(imageviewlist.get(position % imageviewlist.size())); 
   return imageviewlist.get(position % imageviewlist.size()); 
  } 
 } 
 
 
 @override 
 public void onpagescrollstatechanged(int arg0) { 
  // todo auto-generated method stub 
   
 } 
 
 @override 
 public void onpagescrolled(int arg0, float arg1, int arg2) { 
  // todo auto-generated method stub 
   
 } 
 
 /** 
  * 当viewpager页面切换时回调 
  * @param position 就是当前显示的page页 
  */ 
 @override 
 public void onpageselected(int position) { 
  tvimagedescription.settext(imagedescriptions[position % imageviewlist.size()]); 
  llpointgroup.getchildat(position % imageviewlist.size()).setenabled(true); 
  llpointgroup.getchildat(previousposition).setenabled(false); 
   
  previousposition = position % imageviewlist.size(); 
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。