Android自定义ViewPager指示器

 public class ViewPagerIndicator extends HorizontalScrollView{
 public ViewPagerIndicator(Context context) {
  this(context, null);
 }

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

 public ViewPagerIndicator(Context context, AttributeSet attrs,
   int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  this.mContext = context;
 }

 @Override
 public void setViewPager(ViewPager viewPager) {
  if (viewPager == null) {
   throw new NullPointerException("viewPager is null...");
  }
  this.mViewPager = viewPager;

  int count = mViewPager.getAdapter().getCount();
  mContanierGroup.removeAllViews();

  // 循环添加tabView(TextView)
  for (int i = 0; i < count; i++) {
   final TextView itemTv = new TextView(mContext);
   itemTv.setText(this.mViewPager.getAdapter().getPageTitle(i));
   setItemClickEvent(itemTv, i);
   mContanierGroup.addTabView(itemTv);
   setItemClickEvent(itemTv, i);
   mContanierGroup.addTabView(itemTv);
  }

  setItemParams();

  mAdapter.highLightTabView(mContanierGroup.getTabView(mCureentItem));

  this.mViewPager.setOnPageChangeListener(this);
 }

 private void setItemParams() {
  if (mVisibleTabCount != 0) {
   final int childCount = mViewPager.getAdapter().getCount();
   mRunnable = new Runnable() {
    @Override
    public void run() {
     int tabWidth = getWidth() / mVisibleTabCount;
     // 循环遍历设置Tab宽度
     for (int index = 0; index < childCount; index++) {
      LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) mContanierGroup
        .getTabView(index).getLayoutParams();
      params.width = tabWidth;
     }

     // 设置宽度，高度，和角标指示器
     mContanierGroup.setTabWidth(tabWidth);
     mContanierGroup.getContainer().getLayoutParams().height = getHeight();
     mContanierGroup.setIndicatorView(mAdapter.getIndexView());

     mRunnable = null;
    }
   };

   post(mRunnable);
  }
 }
}

 @Override
 public void onPageScrollStateChanged(int position) {
  if (position == 0) {
   // 设置为不是点击
   mIsClick = false;
  }
  if (mPageChangeListener != null)
   mPageChangeListener.onPageScrollStateChanged(position);
 }

 @Override
 public void onPageScrolled(int position, float offset, int arg2) {
  scroll(position, offset);
  if (mPageChangeListener != null)
   mPageChangeListener.onPageScrolled(position, offset, arg2);
 }

 @Override
 public void onPageSelected(int position) {

  mCureentItem = position;

  if (mPageChangeListener != null)
   mPageChangeListener.onPageSelected(position);


 }

 /**
  * 指示器跟随手指进行滚动
  */
 public void scroll(int position, float offset) {

  int tabWidth = mContanierGroup.getTabView(0).getWidth();

  // 让选中Tab的一直在最中间
  int total = (int) ((position + offset) * tabWidth);
  int green = (getWidth() - tabWidth) / 2;

  // 滚动的距离
  int scroll = total - green;

  if (!mIsClick) {
   this.scrollTo(scroll, 0);
   mContanierGroup.scrollIndicator(position, offset);
  }
 }

public abstract class IndicatorAdapter<T extends View> {
 /**
  * 获取Tab View
  */
 public abstract T getTabView(int position);

 /**
  * 获取角标View
  */
 public View getIndexView() {
  return null;
 }

 /**
  * 高亮当前Tab
  */
 public void highLightTabView(T tabView) {

 }

 /**
  * 恢复当前Tab
  */
 public void restoreTabView(T tabView) {

 }
}

 mIndicator.setAdapter(mViewpager, new IndicatorAdapter<TextView>() {

   @Override
   public TextView getTabView(int position) {
    TextView tabView = new TextView(getBaseContext());
    tabView.setTextColor(Color.WHITE);
    tabView.setText(mTitles.get(position));
    tabView.setPadding(20, 20, 20, 20);
    tabView.setGravity(Gravity.CENTER);
    return tabView;
   }

   @Override
   public View getIndexView() {
    ImageView view = new ImageView(getBaseContext());
    view.setImageResource(R.drawable.corners_login_nomral);
    view.setPadding(25, 0, 25, 0);
    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
      LayoutParams.WRAP_CONTENT, 6);
    view.setLayoutParams(params);
    return view;
   }

   @Override
   public void highLightTabView(TextView tabView) {
    final TextView itemView = (TextView) tabView;
    itemView.setTextColor(Color.RED);
   }

   @Override
   public void restoreTabView(TextView tabView) {
    final TextView itemView = (TextView) tabView;
    itemView.setTextColor(Color.WHITE);
   }
  });