Android实现轮播效果的两种方法

实现轮播效果有2种方法:

(1)使用viewpager+imageview,通过handler进行间隔发送消息,实现自动轮播效果

xml代码:

<android.support.v4.view.viewpager
    android:id="@+id/fragment_viewpager"
    android:layout_width="match_parent"
    android:layout_height="200dp" />

 private handler handler=new handler(){
    @override
    public void handlemessage(message msg) {
      super.handlemessage(msg);
      list= (list<bannerbean>) msg.obj;
      //进行下载图片
      for (int i = 0; i < 3; i++) {
        picasso.with(getactivity()).load(list.get(i).getimgs()).resize(640,400).into(imgs.get(i));
      }
      //展示图片
      myadapter adapter=new myadapter();
      viewpager.setadapter(adapter);
    }
  };
  private handler handler2=new handler(){
    @override
    public void handlemessage(message msg) {
      super.handlemessage(msg);
      //获取当前viewpager的位置
      int pos=viewpager.getcurrentitem();
      //如果是最后一张图片就进行设置为第一张,实现循环
      if(pos==imgs.size()-1){
        pos=0;
       //否则进行下一张图片展示
      }else{
        pos++;
      }
      //设置viewpager的位置
      viewpager.setcurrentitem(pos);
      //定时发送消息
      handler2.sendemptymessagedelayed(1,2000);
    }
  };
   @override
  public view oncreateview(layoutinflater inflater, viewgroup container,
               bundle savedinstancestate) {
    view view=inflater.inflate(r.layout.fragment_recreation, container, false);
    initview(view);
    load();
    //发送消息给handler2,实现自动轮播
    handler2.sendemptymessagedelayed(1,2000);
    initlistener();
    return view;
  }
   private void load() {
    //下载图片地址
    new thread(){
      @override
      public void run() {
        super.run();
        string json= utils.getjsonfromnet(contenturls.headline_head+0);
        if(!textutils.isempty(json)){
          list<bannerbean>data= parserbanner.getdata(json);
          message msg=new message();
          msg.obj=data;
          handler.sendmessage(msg);
        }
      }
    }.start();
    data=new arraylist<>();
    headlineadapter=new headlineadapter(data,getactivity());
    lv.setadapter(headlineadapter);
    new myasynctask(data,headlineadapter).execute(contenturls.headline_head+num);

  }
  private void initview(view view) {
    lv = ((listview) view.findviewbyid(r.id.lv));
    headerview = layoutinflater.from(getactivity()).inflate(r.layout.header_layout,null,false);
    viewpager = ((viewpager)headerview.findviewbyid(r.id.fragment_viewpager));
    lv.addheaderview(headerview);
    list=new arraylist<>();
    imgs=new arraylist<>();
    for (int i = 0; i < 3; i++) {
      imageview iv=new imageview(getactivity());
      imgs.add(iv);
    }

  }

adapter:

 class myadapter extends pageradapter{

    @override
    public int getcount() {
      return imgs.size();
    }

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

    @override
    public object instantiateitem(viewgroup container, int position) {
      container.addview(imgs.get(position));
      return imgs.get(position);
    }

    @override
    public void destroyitem(viewgroup container, int position, object object) {
//      super.destroyitem(container, position, object);
      container.removeview(imgs.get(position));
    }
  }

(2)使用sliderlayout第三方进行实现轮播

添加依赖:

  compile 'com.squareup.picasso:picasso:2.5.2'
  compile 'com.daimajia.slider:library:1.1.5@aar'
  compile 'com.nineoldandroids:library:2.4.0'

xml代码:

<?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">
  <com.daimajia.slider.library.sliderlayout
    android:id="@+id/header_slider"
    android:layout_width="match_parent"
    android:layout_height="160dp"></com.daimajia.slider.library.sliderlayout>
</linearlayout>

java代码:

private listview lv;
  private string[] title={"烟","超标","标准","审车合格"};
  private int[] imgs={r.mipmap.a,r.mipmap.b,r.mipmap.c,r.mipmap.d};
  private sliderlayout slider;
 @override
  public view oncreateview(layoutinflater inflater, viewgroup container,
               bundle savedinstancestate) {
    view view=inflater.inflate(r.layout.fragment_home_page, container, false);
    lv = ((listview) view.findviewbyid(r.id.homepage_lv));
    view headerview=layoutinflater.from(getactivity()).inflate(r.layout.header_layout,null,false);
    slider = ((sliderlayout) headerview.findviewbyid(r.id.header_slider));
    lv.addheaderview(headerview);
    initslider();
    initdata();
    return view;
  }

  private void initslider() {
    for (int i = 0; i < 4; i++) {
      textsliderview textslider=new textsliderview(getactivity());
      textslider.image(imgs[i]).description(title[i]);
      slider.addslider(textslider);
      textslider.setonsliderclicklistener(new basesliderview.onsliderclicklistener() {
        @override
        public void onsliderclick(basesliderview slider) {
          toast.maketext(getactivity(),slider.getdescription(),toast.length_short).show();
        }
      });
    }
  }

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