<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical"> 
<EditText 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:background="@drawable/search_border" 
android:drawableLeft="@android:drawable/ic_menu_search" 
android:padding="8dp" /> 
<RelativeLayout 
android:layout_width="match_parent" 
android:layout_height="match_parent"> 
<ListView 
android:id="@+id/lv" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:divider="@null" /> 
<TextView 
android:id="@+id/tv" 
android:layout_width="50dp" 
android:layout_height="50dp" 
android:layout_centerInParent="true" 
android:background="#888888" 
android:gravity="center" 
android:textColor="#000000" 
android:textSize="18dp" 
android:visibility="gone" /> 
<com.handsome.tulin.View.NavView 
android:id="@+id/nv" 
android:layout_width="20dp" 
android:layout_height="match_parent" 
android:layout_alignParentRight="true" 
android:layout_margin="16dp" /> 
</RelativeLayout> 
</LinearLayout>

public class NavView extends View { 
private Paint textPaint = new Paint(); 
private String[] s = new String[]{ 
"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", 
"L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", 
"W", "X", "Y", "Z", "#"}; 
//鼠標(biāo)點(diǎn)擊、滑動(dòng)時(shí)選擇的字母 
private int choose = -1; 
//中間的文本 
private TextView tv; 
public NavView(Context context, AttributeSet attrs) { 
super(context, attrs); 
} 
public NavView(Context context) { 
super(context); 
} 
public NavView(Context context, AttributeSet attrs, int defStyleAttr) { 
super(context, attrs, defStyleAttr); 
} 
private void initPaint() { 
textPaint.setTextSize(20); 
textPaint.setAntiAlias(true); 
textPaint.setColor(Color.BLACK); 
} 
@Override 
protected void onDraw(Canvas canvas) { 
super.onDraw(canvas); 
//畫字母 
drawText(canvas); 
} 
/** 
* 畫字母 
* 
* @param canvas 
*/ 
private void drawText(Canvas canvas) { 
//獲取View的寬高 
int width = getWidth(); 
int height = getHeight(); 
//獲取每個(gè)字母的高度 
int singleHeight = height / s.length; 
//畫字母 
for (int i = 0; i < s.length; i++) { 
//畫筆默認(rèn)顏色 
initPaint(); 
//高亮字母顏色 
if (choose == i) { 
textPaint.setColor(Color.RED); 
} 
//計(jì)算每個(gè)字母的坐標(biāo) 
float x = (width - textPaint.measureText(s[i])) / 2; 
float y = (i + 1) * singleHeight; 
canvas.drawText(s[i], x, y, textPaint); 
//重置顏色 
textPaint.reset(); 
} 
} 
}

public class MainActivity extends AppCompatActivity { 
private TextView tv; 
private ListView lv; 
private NavView nv; 
private List<User> list; 
private UserAdapter adapter; 
private String[] name = new String[]{ 
"潘粵明", "戴軍", "薛之謙", "藍(lán)雨", "任泉", "張杰", "秦俊杰", 
"陳坤", "田亮", "夏雨", "保劍鋒", "陸毅", "喬振宇", "吉杰", "郭敬明", "巫迪文", "歡子", "井柏然", 
"左小祖咒", "段奕宏", "毛寧", "樊凡", "湯潮", "山野", "陳龍", "侯勇", "俞思遠(yuǎn)", "馮紹峰", "崔健", 
"杜淳", "張翰", "彭坦", "柏栩栩", "蒲巴甲", "凌瀟肅", "毛方圓", "武藝", "耿樂", "錢泳辰"}; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_main); 
initView(); 
initData(); 
} 
private void initView() { 
tv = (TextView) findViewById(R.id.tv); 
lv = (ListView) findViewById(R.id.lv); 
nv = (NavView) findViewById(R.id.nv); 
nv.setTextView(tv); 
} 
private void initData() { 
//初始化數(shù)據(jù) 
list = new ArrayList<>(); 
for (int i = 0; i < name.length; i++) { 
list.add(new User(name[i], CharacterUtils.getFirstSpell(name[i]).toUpperCase())); 
} 
//將拼音排序 
Collections.sort(list, new Comparator<User>() { 
@Override 
public int compare(User lhs, User rhs) { 
return lhs.getFirstCharacter().compareTo(rhs.getFirstCharacter()); 
} 
}); 
//填充ListView 
adapter = new UserAdapter(this, list); 
lv.setAdapter(adapter); 
} 
}

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="#ffffff" 
android:orientation="vertical"> 
<TextView 
android:id="@+id/tv_firstCharacter" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:background="#DBDBDA" 
android:padding="8dp" 
android:text="A" 
android:textColor="#000000" 
android:textSize="14dp" /> 
<TextView 
android:id="@+id/tv_name" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
android:background="#ffffff" 
android:padding="8dp" 
android:text="張棟梁" 
android:textColor="#2196F3" 
android:textSize="14dp" /> 
</LinearLayout>

public class UserAdapter extends BaseAdapter { 
private List<User> list; 
private User user; 
private LayoutInflater mInflater; 
private Context context; 
public UserAdapter(Context context, List<User> list) { 
this.list = list; 
mInflater = LayoutInflater.from(context); 
this.context = context; 
} 
@Override 
public int getCount() { 
return list.size(); 
} 
@Override 
public Object getItem(int position) { 
return list.get(position); 
} 
@Override 
public long getItemId(int position) { 
return position; 
} 
@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
if (convertView == null) { 
convertView = mInflater.inflate(R.layout.adapter_user, null); 
} 
ViewHolder holder = getViewHolder(convertView); 
user = list.get(position); 
if (position == 0) { 
//第一個(gè)數(shù)據(jù)要顯示字母和姓名 
holder.tv_firstCharacter.setVisibility(View.VISIBLE); 
holder.tv_firstCharacter.setText(user.getFirstCharacter()); 
holder.tv_name.setText(user.getUsername()); 
} else { 
//其他數(shù)據(jù)判斷是否為同個(gè)字母，這里使用Ascii碼比較大小 
if (CharacterUtils.getCnAscii(list.get(position - 1).getFirstCharacter().charAt(0)) < 
CharacterUtils.getCnAscii(user.getFirstCharacter().charAt(0))) { 
//后面字母的值大于前面字母的值，需要顯示字母 
holder.tv_firstCharacter.setVisibility(View.VISIBLE); 
holder.tv_firstCharacter.setText(user.getFirstCharacter()); 
holder.tv_name.setText(user.getUsername()); 
} else { 
//后面字母的值等于前面字母的值，不顯示字母 
holder.tv_firstCharacter.setVisibility(View.GONE); 
holder.tv_name.setText(user.getUsername()); 
} 
} 
return convertView; 
} 
/** 
* 獲得控件管理對象 
* 
* @param view 
* @return 
*/ 
private ViewHolder getViewHolder(View view) { 
ViewHolder holder = (ViewHolder) view.getTag(); 
if (holder == null) { 
holder = new ViewHolder(view); 
view.setTag(holder); 
} 
return holder; 
} 
/** 
* 控件管理類 
*/ 
private class ViewHolder { 
private TextView tv_firstCharacter, tv_name; 
ViewHolder(View view) { 
tv_firstCharacter = (TextView) view.findViewById(R.id.tv_firstCharacter); 
tv_name = (TextView) view.findViewById(R.id.tv_name); 
} 
} 
/** 
* 通過字符查找位置 
* 
* @param s 
* @return 
*/ 
public int getSelectPosition(String s) { 
for (int i = 0; i < getCount(); i++) { 
String firChar = list.get(i).getFirstCharacter(); 
if (firChar.equals(s)) { 
return i; 
} 
} 
return -1; 
} 
}

@Override 
public boolean dispatchTouchEvent(MotionEvent event) { 
//計(jì)算選中字母 
int index = (int) (event.getY() / getHeight() * s.length); 
//防止腳標(biāo)越界 
if (index >= s.length) { 
index = s.length - 1; 
} else if (index < 0) { 
index = 0; 
} 
switch (event.getAction()) { 
case MotionEvent.ACTION_DOWN: 
case MotionEvent.ACTION_MOVE: 
setBackgroundColor(Color.GRAY); 
//選中字母高亮 
choose = index; 
//出現(xiàn)中間文字 
tv.setVisibility(VISIBLE); 
tv.setText(s[choose]); 
//調(diào)用ListView連動(dòng)接口 
if (listener != null) { 
listener.touchCharacterListener(s[choose]); 
} 
//重繪 
invalidate(); 
break; 
default: 
setBackgroundColor(Color.TRANSPARENT); 
//取消選中字母高亮 
choose = -1; 
//隱藏中間文字 
tv.setVisibility(GONE); 
//重繪 
invalidate(); 
break; 
} 
return true; 
} 
public onTouchCharacterListener listener; 
public interface onTouchCharacterListener { 
void touchCharacterListener(String s); 
} 
public void setListener(onTouchCharacterListener listener) { 
this.listener = listener; 
} 
/** 
* 傳進(jìn)來一個(gè)TextView 
* 
* @param tv 
*/ 
public void setTextView(TextView tv) { 
this.tv = tv; 
}

//ListView連動(dòng)接口 
nv.setListener(new NavView.onTouchCharacterListener() { 
@Override 
public void touchCharacterListener(String s) { 
int position = adapter.getSelectPosition(s); 
if (position != -1) { 
lv.setSelection(position); 
} 
} 
});