package com.liangrensheng.music_player.player;import java.util.Comparator;import com.liangrensheng.music_player.player.MusicData;/*** PinyinComparator接口用来对ListView中的数据根据A-Z进行排序， 前面两个if判断主要是将不是以汉字开头的数据放在后面* */
public class MusicComparator implements Comparator<MusicData> {@Overridepublic int compare(MusicData o1, MusicData o2) {if (o1.mSortLetter.equals("@") || o2.mSortLetter.equals("#")) {return -1;} else if (o1.mSortLetter.equals("#") || o2.mSortLetter.equals("@")) {return 1;} else {return o1.mSortLetter.compareTo(o2.mSortLetter);}}
}

2、针对原项目ListView中onScroll时间的一些优化，主要是为了使搜索结果页面在滑动的时候依然具有挤压效果。

       mListView.setOnScrollListener(new OnScrollListener() {@Overridepublic void onScrollStateChanged(AbsListView view, int scrollState) {}@Overridepublic void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {if (totalItemCount == 0) { // 如果没有item则无需配置挤压效果titleLayout.setVisibility(View.GONE);return;} else if (totalItemCount == 1) { // 仅有一个的时候是没有nextSection的titleLayout.setVisibility(View.VISIBLE);int section = mListViewAdapter.getSectionForPosition(firstVisibleItem);title.setText(mListViewAdapter.getBean(mListViewAdapter.getPositionForSection(section)).sortLetters);} else {titleLayout.setVisibility(View.VISIBLE);int section = mListViewAdapter.getSectionForPosition(firstVisibleItem);int nextSection = mListViewAdapter.getSectionForPosition(firstVisibleItem + 1);int nextSecPosition = mListViewAdapter.getPositionForSection(+nextSection);if (firstVisibleItem != lastFirstVisibleItem) {MarginLayoutParams params = (MarginLayoutParams) titleLayout.getLayoutParams();params.topMargin = 0; // 初始位置titleLayout.setLayoutParams(params);title.setText(mListViewAdapter.getBean(mListViewAdapter.getPositionForSection(section)).sortLetters);}if (nextSecPosition == firstVisibleItem + 1) { // 实现挤压效果View childView = view.getChildAt(0);if (childView != null) {int titleHeight = titleLayout.getHeight();int bottom = childView.getBottom();MarginLayoutParams params = (MarginLayoutParams) titleLayout.getLayoutParams();if (bottom < titleHeight) {float pushedDistance = bottom - titleHeight;params.topMargin = (int) pushedDistance;titleLayout.setLayoutParams(params);} else if (params.topMargin != 0) {params.topMargin = 0;titleLayout.setLayoutParams(params);}}}lastFirstVisibleItem = firstVisibleItem;}}});

3、快速定位如果点击的字母没有存在节点，则定位到该字母前一个最近的节点。

      sideBar.setOnTouchingLetterChangedListener(new OnTouchingLetterChangedListener() {@Overridepublic void onTouchingLetterChanged(String s) { // 设置右侧触摸监听// 该字母首次出现的位置char ch = s.charAt(0);int position = mListViewAdapter.getPositionForSection(ch);while (position == -1) { // 找不到则找最近的一个ch--;if (ch < 'A')break;position = mListViewAdapter.getPositionForSection(ch);}mListView.setSelection(position);}});

4、支持使用大小写进行搜索，例如存在 广岛之恋-莫文蔚.mp3，无论输入"Guang"还是"guang"还是"广"都能给出搜索结果。

   /*** 根据输入框中的值来过滤数据并更新ListView* * @param filterStr*/private void filterData(String filterStr) { //这个filterStr在传入的时候已经转化为小写的了List<ListViewBean> filterDateList = new ArrayList<ListViewBean>();if (TextUtils.isEmpty(filterStr)) {filterDateList = mListViewSource;tvNoMusic.setVisibility(View.GONE);} else {filterDateList.clear();for (ListViewBean sortModel : mListViewSource) {String name = sortModel.musicName.toLowerCase();// 转为小写在寻找if (name.indexOf(filterStr) != -1|| characterParser.getSelling(name).startsWith(filterStr)) {filterDateList.add(sortModel);}}}// 根据a-z进行排序Collections.sort(filterDateList, listViewComparator);mListViewAdapter.refreshAdapter(filterDateList);lastFirstVisibleItem = -1;// 刷新了列表，布局重新初始化MarginLayoutParams params = (MarginLayoutParams) titleLayout.getLayoutParams();params.topMargin = 0;// 初始位置titleLayout.setLayoutParams(params);if (filterDateList.size() == 0) {tvNoMusic.setVisibility(View.VISIBLE);}}