content: package com.zhongou.adapter;
  
  import android.content.Context;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.BaseAdapter;
  import android.widget.SectionIndexer;
  import android.widget.TextView;
  
  import com.zhongou.R;
  import com.zhongou.model.ContactsEmployeeModel;
  
  import java.util.List;
  
  /**
   * 通讯录 适配
   */
  public class ContactsSortAdapter extends BaseAdapter implements SectionIndexer{
  	private List<ContactsEmployeeModel> list = null;
  	private Context mContext;
  	public ContactsSortAdapter(Context mContext) {
          super();
          this.mContext = mContext;
  
  	}
  	public ContactsSortAdapter(Context mContext, List<ContactsEmployeeModel> 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<ContactsEmployeeModel> 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 ContactsEmployeeModel mContent = list.get(position);
  		if (view == null) {
  			viewHolder = new ViewHolder();
  			view = LayoutInflater.from(mContext).inflate(R.layout.item_contacts, null);
  			viewHolder.tvTitle = (TextView) view.findViewById(R.id.tv_name);
  			viewHolder.tvLetter = (TextView) view.findViewById(R.id.tv_letter);
  			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.getFirstLetter());
  		}else{
  			viewHolder.tvLetter.setVisibility(View.GONE);
  		}
  
  		viewHolder.tvTitle.setText(this.list.get(position).getsEmployeeName());
  
  		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).getFirstLetter().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).getFirstLetter();
  			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;
  	}
  }