笔记21 | 学习整理开源APP(BaseAnimation)程序源码“中的通讯录效果(二)

<ListView
            android:id="@+id/country_lvcountry"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_gravity="center"
            android:divider="@null" />

private PinyinComparator pinyinComparator;sortListView = (ListView) findViewById(R.id.country_lvcountry);
        sortListView.setOnItemClickListener(new OnItemClickListener() { 

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                //这里要利用adapter.getItem(position)来获取当前position所对应的对象
                Toast.makeText(getApplication(), ((SortModel)adapter.getItem(position)).getName(), Toast.LENGTH_SHORT).show();
            }
        });
        SourceDateList = filledData(getResources().getStringArray(R.array.date));
        // 根据a-z进行排序源数据
        Collections.sort(SourceDateList, pinyinComparator);//使用给定的比较器对给定的列表进行排序,相等的元素不会被重新排序。
        adapter = new SortAdapter(this, SourceDateList);
        sortListView.setAdapter(adapter);

public class PinyinComparator implements Comparator<SortModel> {

    public int compare(SortModel o1, SortModel o2) {
        if (o1.getSortLetters().equals("@")
                || o2.getSortLetters().equals("#")) {
            return -1;
        } else if (o1.getSortLetters().equals("#")
                || o2.getSortLetters().equals("@")) {
            return 1;
        } else {
            return o1.getSortLetters().compareTo(o2.getSortLetters());
        }
    }

}

public class SortModel {

    private String name;   //显示的数据
    private String sortLetters;  //显示数据拼音的首字母

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSortLetters() {
        return sortLetters;
    }
    public void setSortLetters(String sortLetters) {
        this.sortLetters = sortLetters;
    }
}

public class SortAdapter extends BaseAdapter implements SectionIndexer{
    private List<SortModel> list = null;
    private Context mContext;

    public SortAdapter(Context mContext, List<SortModel> list) {
        this.mContext = mContext;
        this.list = list;
    }

    /**
     * 当ListView数据发生变化时,调用此方法来更新ListView
     * @param list
     */
    public void updateListView(List<SortModel> list){
        this.list = list;
        notifyDataSetChanged();
    }

    public int getCount() {
        return this.list.size();
    }

    public Object getItem(int position) {
        return list.get(position);
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(final int position, View view, ViewGroup arg2) {
        ViewHolder viewHolder = null;
        final SortModel mContent = list.get(position);
        if (view == null) {
            viewHolder = new ViewHolder();
            view = LayoutInflater.from(mContext).inflate(R.layout.item_sort_listview, null);
            viewHolder.tvTitle = (TextView) view.findViewById(R.id.title);
            viewHolder.tvLetter = (TextView) view.findViewById(R.id.catalog);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }
        //根据position获取分类的首字母的Char ascii值
        int section = getSectionForPosition(position);
        //如果当前位置等于该分类首字母的Char的位置 ，则认为是第一次出现
        if(position == getPositionForSection(section)){
            viewHolder.tvLetter.setVisibility(View.VISIBLE);
            viewHolder.tvLetter.setText(mContent.getSortLetters());
        }else{
            viewHolder.tvLetter.setVisibility(View.GONE); //首字母隐藏
        }   
        viewHolder.tvTitle.setText(this.list.get(position).getName());
        return view;
    }

    final static class ViewHolder {
        TextView tvLetter;
        TextView tvTitle;
    }

    /**
     * 根据ListView的当前位置获取分类的首字母的Char ascii值
     */
    public int getSectionForPosition(int position) {
        return list.get(position).getSortLetters().charAt(0);
    }

    /**
     * 根据分类的首字母的Char ascii值获取其第一次出现该首字母的位置
     */
    public int getPositionForSection(int section) {
        for (int i = 0; i < getCount(); i++) {
            String sortStr = list.get(i).getSortLetters();
            char firstChar = sortStr.toUpperCase().charAt(0);
            if (firstChar == section) {
                return i;
            }
        }
        return -1;
    }

    /**
     * 提取英文的首字母，非英文字母用#代替。
     * 
     * @param str
     * @return
     */
    private String getAlpha(String str) {
        String  sortStr = str.trim().substring(0, 1).toUpperCase();
        // 正则表达式，判断首字母是否是英文字母
        if (sortStr.matches("[A-Z]")) {
            return sortStr;
        } else {
            return "#";
        }
    }

    @Override
    public Object[] getSections() {
        return null;
    }
}