快速索引 (对View的自定义，黑马程序员)

* 应用场景: 微信好友列表, 联系人通讯录, 应用管理, 文件管理
* 功能实现: 
* 1. A-Z索引的绘制. 
* 2. 处理Touch事件. 
* 3. 提供使用监听\回调. 
* 4. 汉字转换成拼音. 
* 5. 进行排序展示.
* 6. 进行分组. 

* 7. 将自定义控件和ListView合体. 

项目结构：

MainActivity:

package com.itheima.quickindex;


import java.util.ArrayList;
import java.util.Collections;


import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.text.TextUtils;
import android.view.View;
import android.widget.ListView;
import android.widget.TextView;


import com.itheima.quickindex.adapter.HaoHanAdapter;
import com.itheima.quickindex.bean.Person;
import com.itheima.quickindex.ui.QuickIndexBar;
import com.itheima.quickindex.ui.QuickIndexBar.OnLetterUpdateListener;
import com.itheima.quickindex.util.Cheeses;


public class MainActivity extends Activity {


private ListView mMainList;
private ArrayList<Person> persons;
private TextView tv_center;


@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

QuickIndexBar bar = (QuickIndexBar) findViewById(R.id.bar);
// 设置监听
bar.setListener(new OnLetterUpdateListener() {
@Override
public void onLetterUpdate(String letter) {
// Utils.showToast(getApplicationContext(), letter);

showLetter(letter);
// 根据字母定位ListView, 找到集合中第一个以letter为拼音首字母的对象,得到索引
for (int i = 0; i < persons.size(); i++) {
Person person = persons.get(i);
String l = person.getPinyin().charAt(0) + "";
if(TextUtils.equals(letter, l)){
// 匹配成功
mMainList.setSelection(i);
break;
}
}
}
});

mMainList = (ListView) findViewById(R.id.lv_main);

persons = new ArrayList<Person>();

// 填充数据 , 排序
fillAndSortData(persons);

mMainList.setAdapter(new HaoHanAdapter(MainActivity.this , persons));

tv_center = (TextView) findViewById(R.id.tv_center);


}


private Handler mHandler = new Handler();

/**
* 显示字母
* @param letter
*/
protected void showLetter(String letter) {
tv_center.setVisibility(View.VISIBLE);
tv_center.setText(letter);

mHandler.removeCallbacksAndMessages(null);
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
tv_center.setVisibility(View.GONE);
}
}, 2000);

}


private void fillAndSortData(ArrayList<Person> persons) {
// 填充数据
for (int i = 0; i < Cheeses.NAMES.length; i++) {
String name = Cheeses.NAMES[i];
persons.add(new Person(name));
}

// 进行排序
Collections.sort(persons);
}
}

HaoHanAdapter:

package com.itheima.quickindex.adapter;


import java.util.ArrayList;


import android.content.Context;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;


import com.itheima.quickindex.R;
import com.itheima.quickindex.bean.Person;


public class HaoHanAdapter extends BaseAdapter {


private Context mContext;
private ArrayList<Person> persons;


public HaoHanAdapter(Context mContext, ArrayList<Person> persons) {
this.mContext = mContext;
this.persons = persons;
}


@Override
public int getCount() {
// TODO Auto-generated method stub
return persons.size();
}


@Override
public Object getItem(int position) {
return persons.get(position);
}


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


@Override
public View getView(int position, View convertView, ViewGroup parent) {

View view = convertView;
if(convertView == null){
view = view.inflate(mContext, R.layout.item_list, null);
}
ViewHolder mViewHolder = ViewHolder.getHolder(view);

Person p = persons.get(position);

String str = null;
String currentLetter = p.getPinyin().charAt(0) + "";
// 根据上一个首字母,决定当前是否显示字母
if(position == 0){
str = currentLetter;
}else {
// 上一个人的拼音的首字母
String preLetter = persons.get(position - 1).getPinyin().charAt(0) + "";
if(!TextUtils.equals(preLetter, currentLetter)){
str = currentLetter;
}
}

// 根据str是否为空,决定是否显示索引栏
mViewHolder.mIndex.setVisibility(str == null ? View.GONE : View.VISIBLE);
mViewHolder.mIndex.setText(currentLetter);
mViewHolder.mName.setText(p.getName());

return view;
}

static class ViewHolder {
TextView mIndex;
TextView mName;


public static ViewHolder getHolder(View view) {
Object tag = view.getTag();
if(tag != null){
return (ViewHolder)tag;
}else {
ViewHolder viewHolder = new ViewHolder();
viewHolder.mIndex = (TextView) view.findViewById(R.id.tv_index);
viewHolder.mName = (TextView) view.findViewById(R.id.tv_name);
view.setTag(viewHolder);
return viewHolder;
}
}

}


}

Person:

package com.itheima.quickindex.bean;


import com.itheima.quickindex.util.PinyinUtils;


public class Person implements Comparable<Person>{


private String name;
private String pinyin;


public Person(String name) {
super();
this.name = name;
this.pinyin = PinyinUtils.getPinyin(name);
}

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPinyin() {
return pinyin;
}
public void setPinyin(String pinyin) {
this.pinyin = pinyin;
}


@Override
public int compareTo(Person another) {
return this.pinyin.compareTo(another.getPinyin());
}

}

以上是主要代码,代码地址：http://download.csdn.net/detail/u013453973/9215001