自定义banner轮播

最新推荐文章于 2019-12-07 18:31:01 发布

wonder-df

最新推荐文章于 2019-12-07 18:31:01 发布

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CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/wxy_wonder/article/details/79936830

本文介绍了一个自定义的轮播图组件实现方法，通过继承RelativeLayout并利用Handler进行消息循环来实现无限轮播效果。该组件支持外部传入图片列表，并能够通过点击小圆点切换图片，同时具备开启和停止轮播的功能。

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public class Mybanner extends RelativeLayout {
    private static final String TAG = "Mybanner";
    private MyHandler myHandler=new MyHandler();
    private View view;
    private ViewPager viewPager;
    private LinearLayout l_points;
    private List<ImageView> point;

    public Mybanner(Context context) {
        this(context,null);
    }

    public Mybanner(Context context, AttributeSet attrs) {
        this(context, attrs,0);
    }

    public Mybanner(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        view = View.inflate(context, R.layout.layout_mybanner, this);
        //获取控件
        viewPager = view.findViewById(R.id.viewpager);
        l_points = view.findViewById(R.id.l_points);
        //设置滑动监听
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                   //切换小圆点
                position = position % point.size();
                for(int i=0; i<point.size();i++){
                    if(i==position){
                        point.get(i).setSelected(true);
                    }else {
                        point.get(i).setSelected(false);
                    }
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }
    //配置适配器
    public void setMyadapter(Context context,List<ImageView> list,String url){
        Log.d(TAG, "setMyadapter: ================"+url);
        Myadapter myadapter = new Myadapter(context,list,url);
        viewPager.setAdapter(myadapter);
        //设置小圆点
        point = new ArrayList<>();
        for(int i=0; i<list.size();i++){
            ImageView image = new ImageView(context);
            image.setImageResource(R.drawable.point_selecter);
            l_points.addView(image);
            point.add(image);
        }
        point.get(0).setSelected(true);

    }
    //开启无限轮播
    public void stratplay(){
        myHandler.sendEmptyMessageDelayed(1,1000);
    }
    //关闭无限轮播
    public void stopplay(){
        myHandler.removeCallbacksAndMessages(null);
    }
    class Myadapter extends PagerAdapter{
    private Context context;
    private List<ImageView> list;
    private String url;

    public Myadapter(Context context, List<ImageView> list,String url) {
            this.context = context;
            this.list = list;
            this.url=url;
        }

        @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) {
            position= position % list.size();
            ImageView imageView = list.get(position);
            Log.d(TAG, "instantiateItem: ++++++++++++++++"+url);
            imageView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent intent=new Intent(context, WebActivity.class);
                    intent.putExtra("zhi",url);
                    context.startActivity(intent);
                }
            });
            container.addView(imageView);

            return imageView;
        }

        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
          container.removeView((ImageView) object);
        }
    }
    class MyHandler extends Handler{
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            int currentItem = viewPager.getCurrentItem();
            currentItem++;
            viewPager.setCurrentItem(currentItem);
            myHandler.sendEmptyMessageDelayed(1,1000);
        }
    }
}

//OKhttp请求网络

   OkHttpClient okHttpClient = new OkHttpClient();
        Request request = new Request.Builder().url(httpconfig.url).build();
        Call call = okHttpClient.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {

            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String s = response.body().string();
                Message message = myHandler.obtainMessage();
                message.obj=s;
                myHandler.sendMessage(message);
            }
        });


//handler线程通信

 class MyHandler extends Handler{

        private String url;

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            String obj = (String) msg.obj;
            Gson gson=new Gson();
            BannerBean bannerBean = gson.fromJson(obj, BannerBean.class);
            List<BannerBean.DataBean> data = bannerBean.getData();
            List<ImageView> images=new ArrayList<>();
            for(int i=0; i<data.size();i++){
                String icon = data.get(i).getIcon();
                url = data.get(i).getUrl();
                ImageView imageView=new ImageView(getActivity());
                //加载网络图片
                Glide.with(getActivity()).load(icon).into(imageView);
                images.add(imageView);
            }

            Log.d(TAG, "handleMessage:----------------------------- "+url);
            //设置适配器
            mybanner.setMyadapter(getActivity(),images,url);
            //开启无限轮播
            mybanner.stratplay();
        }
    }