Android viewpager无限轮播获取网络图片功能

本文实例为大家分享了viewpager无限轮播获取网络图片的具体代码，供大家参考，具体内容如下

话不多说直接上代码，你们都懂的

小圆点属性

dot_focused.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">

 <solid android:color="#f00"/>
 <corners android:radius="8dp"/>
</shape>

 dot_normal.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
 <solid android:color="#88000000"/>
 <corners android:radius="8dp"/>
</shape>　

dot_layout.xml　　

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical" >
 
 <view 
  android:id="@+id/scrollview"
  android:layout_width="8dp"
  android:layout_height="8dp"
  android:layout_margin="3dp"
  android:background="@drawable/dot_normal"
  />

</linearlayout>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 >
 <android.support.v4.view.viewpager
  android:id="@+id/viewpager"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
 </android.support.v4.view.viewpager>
 <linearlayout
  android:id="@+id/ll"
  android:layout_margintop="450dp"
  android:orientation="horizontal"
  android:gravity="center"
  android:layout_width="match_parent"
  android:layout_height="20dp"/>
 
</relativelayout>

以上是布局

下面src代码

import android.content.intent;
import android.os.asynctask;
import android.os.handler;
import android.os.message;
import android.support.v4.view.pageradapter;
import android.support.v4.view.viewpager;
import android.support.v7.app.appcompatactivity;
import android.os.bundle;
import android.view.layoutinflater;
import android.view.view;
import android.view.viewgroup;
import android.widget.button;
import android.widget.imageview;
import android.widget.linearlayout;
import com.bwie.bean.superclass;
import com.bwie.utils.networkutils;
import com.bwie.utils.urldb;
import com.google.gson.gson;
import com.nostra13.universalimageloader.core.imageloader;
import java.util.arraylist;
import java.util.list;
import java.util.timer;
import java.util.timertask;

public class mainactivity extends appcompatactivity {

 private viewpager viewpager;
 private button bt;
 private linearlayout layout;
 private list<superclass.resultbean.databean> data;
 private networkutils networkutils = new networkutils();//实例化工具类
 private list<imageview>imgs = new arraylist<imageview>();//图片的集合
 private list<view> dots = new arraylist<view>(); //小圆点集合
 private int i = 0;
 private int dot = 0;
 private handler handler = new handler(){
  @override
  public void handlemessage(message msg) {
   super.handlemessage(msg);

   viewpager.setcurrentitem(i);
   dots.get(dot).setbackgroundresource(r.drawable.dots_normal);
   dots.get(i%imgs.size()).setbackgroundresource(r.drawable.dots_focus);
   dot=i%imgs.size();
  }
 };
 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);


  //异步网络请求
  new asynctask<string,integer,string>(){

   @override
   protected string doinbackground(string... params) {
    string json = networkutils.getjsonhttpconnetion(urldb.url_ij);
    return json;
   }
   @override
   protected void onpostexecute(string s) {
    super.onpostexecute(s);
    superclass superclass = new gson().fromjson(s, superclass.class);
    data = superclass.getresult().getdata();
    init();//初始化方法
   }
  }.execute();
 }
 //初始化方法
 private void init() {
  viewpager = (viewpager) findviewbyid(r.id.viewpager);
  layout = (linearlayout) findviewbyid(r.id.ll);
  getimgs();//获取图片
  getdots();//获取小圆点
  //viewpager适配器
  viewpager.setadapter(new pageradapter() {
   @override
   public int getcount() {
    return integer.max_value;
   }

   @override
   public boolean isviewfromobject(view view, object object) {
    return view==object;
   }

   @override
   public object instantiateitem(viewgroup container, int position) {

    int i = position % imgs.size();
    imageview imageview = imgs.get(i);
    imageview.setscaletype(imageview.scaletype.fit_xy);
    container.addview(imageview);
    return imageview;
   }

   @override
   public void destroyitem(viewgroup container, int position, object object) {
    container.removeview((view) object);
   }
  });
  //设置初始化位置
  i = imgs.size()*10;
  //得到位置
  viewpager.setcurrentitem(i);
  //设置第一个圆点为true
  dots.get(0).setbackgroundresource(r.drawable.dots_focus);
  //timer自动轮播
  timer timer = new timer();
  timer.schedule(new timertask() {
   @override
   public void run() {
    i = viewpager.getcurrentitem() + 1;
    handler.sendemptymessage(i);
   }
  },1,2000);
 }

 //图片的方法
 private void getimgs() {

  for(int i = 0;i<data.size();i++){
   list<superclass.resultbean.databean.stepsbean> steps = data.get(i).getsteps();
   string url = steps.get(0).getimg();
   imageview img = new imageview(this);
   img.setscaletype(imageview.scaletype.fit_xy);
   imageloader.getinstance().displayimage(url,img);
   imgs.add(img);
  }
 }
 //小圆点的方法
 private void getdots() {

  for(int i=0;i<imgs.size();i++){
   view view = layoutinflater.from(this).inflate(r.layout.dot_item,null);
   view viewbyid = view.findviewbyid(r.id.scrollview);
   dots.add(viewbyid);
   layout.addview(view);
  }
 }
}

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。