<RelativeLayout
  android:id="@ id/parent_layout"
  android:layout_marginTop="10dp"
  android:layout_width="80dp"
  android:layout_height="4dp"
  android:layout_gravity="center"
  android:background="@drawable/bg_store_classify_normal">

  <View
   android:id="@ id/main_line"
   android:layout_width="40dp"
   android:layout_height="4dp"
   android:layout_centerVertical="true"
   android:background="@drawable/bg_store_classify_selected" />
</RelativeLayout>

rcvClassifyTypes.addOnScrollListener(new RecyclerView.OnScrollListener() {
 @Override
 public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
  super.onScrollStateChanged(recyclerView, newState);
 
 }
 
 @Override
 public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
  super.onScrolled(recyclerView, dx, dy);
  //整體的總寬度，注意是整體，包括在顯示區(qū)域之外的
  //滾動條表示的總范圍
  int temp = rcvClassifyTypes.computeHorizontalScrollRange();
  if (temp > range) {
   range = temp;
  }
  //滑塊的偏移量
  int offset = rcvClassifyTypes.computeHorizontalScrollOffset();
  //可視區(qū)域長度
  int extent = rcvClassifyTypes.computeHorizontalScrollExtent();
  //滑出部分在剩余范圍的比例
  float proportion = (float) (offset * 1.0 / (range - extent));
  //計算滾動條寬度
  float transMaxRange = parentLayout.getWidth() - childline.getWidth();
  //設(shè)置滾動條移動
  childline.setTranslationX(transMaxRange * proportion);
 }
});