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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