Android动态加载轮播图BannerView

轮播图在每个app中扮演着一个点缀的角色，在独立做了三款app后都有这个需求，所以我决定把它单独抽出来。以后只需copy,然后再根据需求改一下即可。

/** * 加载网络轮播图 *@author jiangrongtao * *csdn:http://blog.csdn.net/jiang_rong_tao * *github:https://github.com/jiangrongtao/jiangrongtao.github.io * * created at 2016/6/3 9:14*/public class BannerView {    private View bannerView;    private Context mContext;    private Map<String,String> maps;    private FragmentManager manager;    private List<Fragment> mList;    private MyChildViewPager bannerPager;    private ImageView defImage;//设置默认图片    public  static boolean LOAD_FINISH=false;//是成功加载banner    private LinearLayout llDots;//下部的小白点的布局    public  boolean isRoll = false;//是否轮播    private List<View> dotList = new ArrayList<View>();//存放小白点    private static final String TAG = "BannerView";    public BannerView(Context context,Map<String,String> maps,FragmentManager manager){        this.mContext=context;        this.maps=maps;        this.manager=manager;        mList=new ArrayList<Fragment>();    }    protected Handler handler = new Handler() {        public void handleMessage(Message msg) {            switch (msg.what){                case 1:                    final List<BannerInfo> data = (List<BannerInfo>) msg.obj;                    setBannerInfo(data);                    break;                case 2:                    LOAD_FINISH=false;                    defImage.setVisibility(View.VISIBLE);                    break;                case 3:                    if (mList.size() > 0) {                        bannerPager.setCurrentItem((bannerPager.getCurrentItem() + 1) % mList.size());                    } else {                        isRoll = false;                    }                    break;            }        }    };    /**     * 设置banner信息     * @param data     */    private void setBannerInfo(final List<BannerInfo> data) {        mList.clear();        for (int i = 0; i < data.size(); i++) {            final int j = i;            final ImageView imageView = new ImageView(mContext);            BannerInfo bannerInfo = data.get(i);            APIImageLoader.displayImage(mContext,bannerInfo.getUrl(), R.drawable.banner_fial,R.drawable.banner_fial,imageView);            imageView.setOnClickListener(new View.OnClickListener() {             @Override                public void onClick(View v) {                    String hrefUrl = data.get(j).getHrefUrl();                    if (!TextUtils.isEmpty(hrefUrl)) {                        Intent intent = new Intent(mContext, AppDetailActivity.class);                        intent.putExtra("hrefUrl", hrefUrl);                        mContext.startActivity(intent);                    }                }            });            Fragment fragment = new Fragment() {                @Override                public View onCreateView(LayoutInflater inflater, ViewGroup container,                                         Bundle savedInstanceState) {                    return imageView;                }            };            mList.add(fragment);        }        if(mList.size()>0){            defImage.setVisibility(View.GONE);            bannerPager.setAdapter(new BannerAdapter(manager, mList));            initDot();            bannerPager.setCurrentItem(0);            LOAD_FINISH=true;        }else{            LOAD_FINISH=false;            defImage.setVisibility(View.VISIBLE);        }    }    public View getBannerView() {        bannerView=View.inflate(mContext, R.layout.banner_layout,null);        bannerPager= (MyChildViewPager) bannerView.findViewById(R.id.banner_pager);        defImage = (ImageView)bannerView.findViewById(R.id.iv_default_page);        llDots=(LinearLayout)bannerView.findViewById(R.id.ll_dots);        initBannersData();        return bannerView;    }    /*    * 设置循环轮播    * */    public void setBannerCycle(long loopTime){        if(LOAD_FINISH){            if(null!=bannerPager){                isRoll=true;                startLooper(loopTime);                bannerPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {                    @Override                    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {                    }                    @Override                    public void onPageSelected(int position) {                        switchDot(position);                    }                    @Override                    public void onPageScrollStateChanged(int state) {                    }                });            }        }    }    /**     * 开启轮播     * @param loopTime 轮播间隔时间     */    private void startLooper(final long loopTime) {        new Thread() {            public void run() {                while (isRoll) {                   handler.sendEmptyMessageDelayed(3,loopTime);                }            };        }.start();    }    //获取网络banner图片    private void initBannersData() {        maps.clear();        RequestManager.getInstance(mContext).sendPost(APIConfig.GET_BANNERS, maps, BannerRes.class, new Callback<BannerRes>() {            @Override            public BannerRes parseNetworkResponse(Response response) throws Exception {                return  GsonUtils.object(response.body().string(),BannerRes.class);            }            @Override            public void onError(Call call, Exception e) {            }            @Override            public void onResponse(BannerRes response) {                if(APIResCode.SUCCESS.equals(response.getResCode())){                    List<BannerInfo> data = response.getData();                    if (data!=null&&data.size()>0){                        handler.sendMessage(handler.obtainMessage(1, data));                    }else{                        handler.sendEmptyMessage(2);                    }                }            }        });    }    /**     * 初始化小圆点     */    private void initDot() {        llDots.removeAllViews();        dotList.clear();        for (int i = 0; i < mList.size(); i++) {            View view = new View(mContext);            //默认选中第一个小白点            view.setBackgroundResource(i == 0?R.drawable.dot_sel:R.drawable.dot_nor);            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(8, 8);            params.setMargins(0, 0, 12, 0);            llDots.addView(view, params);            dotList.add(view);        }    }    /**     * 切换圆点     */    private void switchDot(int position) {        for (int i = 0; i < dotList.size(); i++) {            dotList.get(i).setBackgroundResource(i == position?R.drawable.dot_sel:R.drawable.dot_nor);        }    }}

轮播图适配器：

public class BannerAdapter extends FragmentPagerAdapter{    List<Fragment> list ;    public BannerAdapter(FragmentManager fm, List<Fragment> list) {        super(fm);        this.list = list ;    }    @Override    public  Fragment getItem(int index) {        return list.get(index%list.size());    }    @Override    public int getCount() {        return list.size();    }}

布局文件：

<?xml version="1.0" encoding="utf-8"?><FrameLayoutxmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="wrap_content"android:gravity="center" >    <com.jianzhilaila.money.ui.view.myviewpager.MyChildViewPager        android:id="@+id/banner_pager"        android:layout_width="match_parent"        android:layout_height="200dp">    </com.jianzhilaila.money.ui.view.myviewpager.MyChildViewPager>    <ImageView        android:id="@+id/iv_default_page"        android:layout_width="match_parent"        android:layout_height="208dp"        android:background="@drawable/banner_fial" />    <LinearLayout    android:id="@+id/ll_dots"    android:layout_width="match_parent"    android:layout_height="8dp"    android:layout_alignParentBottom="true"    android:gravity="center"    android:layout_gravity="bottom"    android:layout_marginBottom="10dp"    android:orientation="horizontal" /></FrameLayout>

具体用法

//获取banner BannerView bannerView = new BannerView(context, maps,   getChildFragmentManager());        View banner = bannerView.getBannerView();        mLinearLayout.addView(banner,0);        bannerView.setBannerCycle(1500);

在onDestroyView()或onDestroy()中记得设置：**isRoll=false;** ,避免内存溢出。mLinearLayout是轮播图页面的根布局。getChildFragmentManager是由于我的Viewpager是嵌套使用的。MyChildViewPager 是一个自定义的防止嵌套使用滑动事件冲突的类。RequestManager和APIImageLoader是我自己二次封装的网络请求和图片加载类，在我以前的博客http://blog.csdn.net/jiang_rong_tao/article/details/51516977中。

注意：上面代码有很多要改进的地方，如果有bug自己修复，可以把改进的代码分享一下。