Android开发实现广告无限循环功能示例

/** * 新闻首页 * * @Project App_Card * @Package com.android.koomama.fragment.home * @author chenlin * @version 1.0 * @Date 2014年6月22日 * @Note TODO */public class NewsHomeFragment extends BaseFragment implements OnTouchListener {  private ImageHandler mHandler = new ImageHandler(new WeakReference<NewsHomeFragment>(this));  private ViewPager mViewPager;  // 自定义轮播图的资源  private int[] mImageResIds = { R.drawable.img1, R.drawable.img2, R.drawable.img3, R.drawable.img4, R.drawable.img5 };  // 放轮播图片的ImageView 的list  private List<ImageView> mImageList = new ArrayList<ImageView>();  // 放圆点的View的list  private List<View> mDotList = new ArrayList<View>();  @Override  public View initConvertView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {    return inflater.inflate(R.layout.fragment_news_main, container, false);  }  @Override  protected void onVisible(boolean isInit) {    if (isInit) {      initViews();    }  }  private void initViews() {    // 初始化iewPager的内容    mViewPager = (ViewPager) mConvertView.findViewById(R.id.view_pager);    LinearLayout dotLayout = (LinearLayout) mConvertView.findViewById(R.id.dotLayout);    dotLayout.removeAllViews();    for (int i = 0; i < mImageResIds.length; i++) {      ImageView imageView = new ImageView(getActivity());      imageView.setScaleType(ScaleType.FIT_XY);      // view.setTag(mImageResId[i]);      imageView.setImageResource(mImageResIds[i]);      mImageList.add(imageView);      View dotView = new View(getActivity());      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(getResources().getDimensionPixelSize(R.dimen.dot_width),          getResources().getDimensionPixelSize(R.dimen.dot_width));      params.setMargins(4, 0, 4, 0);      dotView.setLayoutParams(params);//     if (i == 0) {//       dotView.setBackgroundResource(R.drawable.dot_red);//     } else {//       dotView.setBackgroundResource(R.drawable.dot_gray);//     }      dotLayout.addView(dotView);      mDotList.add(dotView);    }    mViewPager.setAdapter(new ImageAdapter(mImageList));    mViewPager.setOnPageChangeListener(new PageChangeListener());    mViewPager.setFocusable(true);    mViewPager.setCurrentItem(Integer.MAX_VALUE / 2);// 默认在中间，使用户看不到边界    mViewPager.setOnTouchListener(this);    // 开始轮播效果    mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE, ImageHandler.MSG_DELAY);  }  @Override  public boolean onTouch(View v, MotionEvent event) {    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      mHandler.sendEmptyMessage(ImageHandler.MSG_KEEP_SILENT);      break;    case MotionEvent.ACTION_UP:    case MotionEvent.ACTION_CANCEL:      mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE, ImageHandler.MSG_DELAY);      break;    }    return false;  }  private class PageChangeListener implements OnPageChangeListener {    // 配合Adapter的currentItem字段进行设置。    @Override    public void onPageSelected(int position) {      // 这个是设置左滑切换底部view的边界，必须要设置      App.getInstance().setBorderViewPosition(position);      mHandler.sendMessage(Message.obtain(mHandler, ImageHandler.MSG_PAGE_CHANGED, position, 0));    }    @Override    public void onPageScrolled(int position, float arg1, int arg2) {    }    // 覆写该方法实现轮播效果的暂停和恢复    @Override    public void onPageScrollStateChanged(int state) {      switch (state) {      case ViewPager.SCROLL_STATE_DRAGGING:        mHandler.sendEmptyMessage(ImageHandler.MSG_KEEP_SILENT);        break;      case ViewPager.SCROLL_STATE_IDLE:        mHandler.sendEmptyMessageDelayed(ImageHandler.MSG_UPDATE_IMAGE, ImageHandler.MSG_DELAY);        break;      default:        break;      }    }  }  private class ImageAdapter extends PagerAdapter {    private List<ImageView> viewlist;    public ImageAdapter(List<ImageView> viewlist) {      this.viewlist = viewlist;    }    @Override    public int getCount() {      // 设置成最大，使用户看不到边界      return Integer.MAX_VALUE;    }    @Override    public boolean isViewFromObject(View arg0, Object arg1) {      return arg0 == arg1;    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {      // Warning：不要在这里调用removeView    }    @Override    public Object instantiateItem(ViewGroup container, int position) {      // 对ViewPager页号求模取出View列表中要显示的项      position %= viewlist.size();      if (position < 0) {        position = viewlist.size() + position;      }      ImageView view = viewlist.get(position);      // 如果View已经在之前添加到了一个父组件，则必须先remove，否则会抛出IllegalStateException。      ViewParent vp = view.getParent();      if (vp != null) {        ViewGroup parent = (ViewGroup) vp;        parent.removeView(view);      }      container.addView(view);      // 此处可添加监听事件      return view;    }  }  private static class ImageHandler extends Handler {    /**     * 请求更新显示的View。     */    protected static final int MSG_UPDATE_IMAGE = 1;    /**     * 请求暂停轮播。     */    protected static final int MSG_KEEP_SILENT = 2;    /**     * 请求恢复轮播。     */    protected static final int MSG_BREAK_SILENT = 3;    /**     * 记录最新的页号，当用户手动滑动时需要记录新页号，否则会使轮播的页面出错。     * 例如当前如果在第一页，本来准备播放的是第二页，而这时候用户滑动到了末页，     * 则应该播放的是第一页，如果继续按照原来的第二页播放，则逻辑上有问题。     */    protected static final int MSG_PAGE_CHANGED = 4;    // 轮播间隔时间    protected static final long MSG_DELAY = 3000;    // 使用弱引用避免Handler泄露.这里的泛型参数可以不是Activity，也可以是Fragment等    private WeakReference<NewsHomeFragment> weakReference;    private int currentItem = 0;    // private boolean isOnce = true;    protected ImageHandler(WeakReference<NewsHomeFragment> wk) {      weakReference = wk;    }    @Override    public void handleMessage(Message msg) {      super.handleMessage(msg);      final NewsHomeFragment fragment = weakReference.get();      if (fragment == null) {        // Activity已经回收，无需再处理UI了        return;      }      // 第一次不删重复的消息      if (currentItem != 0) {        // 检查消息队列并移除未发送的消息，这主要是避免在复杂环境下消息出现重复等问题。        if (fragment.mHandler.hasMessages(MSG_UPDATE_IMAGE)) {          fragment.mHandler.removeMessages(MSG_UPDATE_IMAGE);        }      }      switch (msg.what) {      case MSG_UPDATE_IMAGE:        currentItem++;        fragment.mViewPager.setCurrentItem(currentItem);        // 准备下次播放        fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE, MSG_DELAY);        break;      case MSG_KEEP_SILENT:        // 只要不发送消息就暂停了        break;      case MSG_BREAK_SILENT:        fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE, MSG_DELAY);        break;      case MSG_PAGE_CHANGED:        // 记录当前的页号，避免播放的时候页面显示不正确。        int position = msg.arg1;        int lastIndex = 0;        int index = position % fragment.mImageList.size();        for (int i = 0; i < fragment.mDotList.size(); i++) {          fragment.mDotList.get(i).setBackgroundResource(R.drawable.dot_normal);        }        if (fragment.mDotList.get(index)!=null) {          fragment.mDotList.get(index).setBackgroundResource(R.drawable.dot_red);        }        lastIndex = index;        currentItem = position;        break;      default:        break;      }    }  }}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"  tools:context=".MainActivity" >  <RelativeLayout    android:layout_width="fill_parent"    android:layout_height="@dimen/news_pic_height" >    <android.support.v4.view.ViewPager      android:id="@+id/view_pager"      android:layout_width="match_parent"      android:layout_height="@dimen/news_pic_height" />    <LinearLayout      android:id="@+id/dotLayout"      android:layout_width="match_parent"      android:layout_height="wrap_content"      android:layout_alignParentBottom="true"      android:gravity="right|bottom"      android:orientation="horizontal"      android:background="@color/transparent_white_half"      android:padding="8dp" >      <View        android:id="@+id/v_dot1"        android:layout_width="@dimen/dot_width"        android:layout_height="@dimen/dot_width"        android:background="@drawable/dot_normal" />      <View        android:id="@+id/v_dot2"        android:layout_width="@dimen/dot_width"        android:layout_height="@dimen/dot_width"        android:layout_marginLeft="5dp"        android:background="@drawable/dot_red" />    </LinearLayout>  </RelativeLayout></LinearLayout>