本文實例講述了Android開發(fā)實現(xiàn)廣告無限循環(huán)功能。分享給大家供大家參考,具體如下:
一、效果圖:
	
二、代碼實現(xiàn):
/** * 新聞首頁 * * @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;  // 自定義輪播圖的資源  private int[] mImageResIds = { R.drawable.img1, R.drawable.img2, R.drawable.img3, R.drawable.img4, R.drawable.img5 };  // 放輪播圖片的ImageView 的list  private List<ImageView> mImageList = new ArrayList<ImageView>();  // 放圓點的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的內容    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);// 默認在中間,使用戶看不到邊界    mViewPager.setOnTouchListener(this);    // 開始輪播效果    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字段進行設置。    @Override    public void onPageSelected(int position) {      // 這個是設置左滑切換底部view的邊界,必須要設置      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) {    }    // 覆寫該方法實現(xiàn)輪播效果的暫停和恢復    @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() {      // 設置成最大,使用戶看不到邊界      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:不要在這里調用removeView    }    @Override    public Object instantiateItem(ViewGroup container, int position) {      // 對ViewPager頁號求模取出View列表中要顯示的項      position %= viewlist.size();      if (position < 0) {        position = viewlist.size() + position;      }      ImageView view = viewlist.get(position);      // 如果View已經(jīng)在之前添加到了一個父組件,則必須先remove,否則會拋出IllegalStateException。      ViewParent vp = view.getParent();      if (vp != null) {        ViewGroup parent = (ViewGroup) vp;        parent.removeView(view);      }      container.addView(view);      // 此處可添加監(jiān)聽事件      return view;    }  }  private static class ImageHandler extends Handler {    /**     * 請求更新顯示的View。     */    protected static final int MSG_UPDATE_IMAGE = 1;    /**     * 請求暫停輪播。     */    protected static final int MSG_KEEP_SILENT = 2;    /**     * 請求恢復輪播。     */    protected static final int MSG_BREAK_SILENT = 3;    /**     * 記錄最新的頁號,當用戶手動滑動時需要記錄新頁號,否則會使輪播的頁面出錯。     * 例如當前如果在第一頁,本來準備播放的是第二頁,而這時候用戶滑動到了末頁,     * 則應該播放的是第一頁,如果繼續(xù)按照原來的第二頁播放,則邏輯上有問題。     */    protected static final int MSG_PAGE_CHANGED = 4;    // 輪播間隔時間    protected static final long MSG_DELAY = 3000;    // 使用弱引用避免Handler泄露.這里的泛型參數(shù)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已經(jīng)回收,無需再處理UI了        return;      }      // 第一次不刪重復的消息      if (currentItem != 0) {        // 檢查消息隊列并移除未發(fā)送的消息,這主要是避免在復雜環(huán)境下消息出現(xiàn)重復等問題。        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);        // 準備下次播放        fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE, MSG_DELAY);        break;      case MSG_KEEP_SILENT:        // 只要不發(fā)送消息就暫停了        break;      case MSG_BREAK_SILENT:        fragment.mHandler.sendEmptyMessageDelayed(MSG_UPDATE_IMAGE, MSG_DELAY);        break;      case MSG_PAGE_CHANGED:        // 記錄當前的頁號,避免播放的時候頁面顯示不正確。        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;      }    }  }}三、布局
<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>
希望本文所述對大家Android程序設計有所幫助。
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