先上效果图，呵呵，首先说明这个效果本人还是比较满意的~
首先来分析一下页面元素的，其实就是左侧的一个listview和右侧的一个自定义linearlayout，右侧部分进行滑动时，左侧的联系人可以随着字母进行移动。
这个效果用到的知识还是挺多的。然而“青青翠竹无非般若，郁郁黄花皆是妙谛”，认清了事务的内在规律都是不难，接着允许本人讲一下~
1、普及知识，汉字转gb2312码和byte型数据
gb2312中的英文字符是与ascii码一致的，一个字节。汉字字符是两个字节，分为高八位和低八位：高字节的值为0xA0+区号，低字节的值为0xA0+位号。
汉字的区号值从16-87，位号值从1-94，（从这里我们可以算出来收录的汉字数量为：69*94 = 6456个），从上表中，我们可以看到同一个拼音的汉字中间是断代的，16-55区号的汉字的位号都是连续值，即所谓“一级汉字”（常用字），56-87区号的汉字位号是断的，即“二级汉字”。实际上这个类就只能识别一级汉字，作者使用了一个简单的障眼法，让人不容易看明白，后面看笔者将其拆穿。
接下来看看byte型数据，因为类中使用了String.getBytes()，欲知汉字如何转换为拼音，了解数据在内存中的存储形式至关重要，基本的补码知识请参考: http://perfect5085.iteye.com/blog/1612694;如果您确定了解补码知识就可以往下看了：
咳咳，接下来，就是本人的测试程序来，来干什么呢？强化您的补码知识...
public class Test {
public static void main(String[] args){
String a = "啊";//啊的高字节（byte[0]）的值为0xA0+0x10= 0xB0 = 176（10进制） = 10110000
byte[] bytes = null; byte mbyte= -80; try { bytes = a.getBytes("gb2312"); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println(Integer.toBinaryString(bytes[0])); System.out.println(Integer.toBinaryString(mbyte)); System.out.println(mbyte); } }
您可以先猜一下输出值再看一下我的测试结果
注意！笔者的注释是写错了的，或者是不完整，应该是这样的一个过场，两个十六进制的int值相加，结果为176，这个176的int值是正数，所以补码还是176，末八位是10110000，但是通过getbytes（）转化为byte值时，计算机在内存中直接将其补码拿过来用，末八位仍然是10110000，所以输出二进制时候直接把内存中的输出来，但是输出十进制时候计算机就不能直接输出补码了，他得把补码还原成源码，然后计算出对应的十进制数值来，即11010000、-80.
好了，恶补一顿开始我们的传道授业解惑之旅吧~
我看先看这个拼音parser类：
package com.gensoft.autopet.fragment.bluetooth;
/**
* Java汉字转换为拼音
*/
public class CharacterParser {
private static int[] pyvalue = new int[] {-20319, -20317, -20304, -20295, -20292, -20283, -20265, -20257, -20242, -20230, -20051, -20036, -20032,
-20026, -20002, -19990, -19986, -19982, -19976, -19805, -19784, -19775, -19774, -19763, -19756, -19751, -19746, -19741, -19739, -19728,
-19725, -19715, -19540, -19531, -19525, -19515, -19500, -19484, -19479, -19467, -19289, -19288, -19281, -19275, -19270, -19263, -19261,
-19249, -19243, -19242, -19238, -19235, -19227, -19224, -19218, -19212, -19038, -19023, -19018, -19006, -19003, -18996, -18977, -18961,
-18952, -18783, -18774, -18773, -18763, -18756, -18741, -18735, -18731, -18722, -18710, -18697, -18696, -18526, -18518, -18501, -18490,
-18478, -18463, -18448, -18447, -18446, -18239, -18237, -18231, -18220, -18211, -18201, -18184, -18183, -18181, -18012, -17997, -17988,
-17970, -17964, -17961, -17950, -17947, -17931, -17928, -17922, -17759, -17752, -17733, -17730, -17721, -17703, -17701, -17697, -17692,
-17683, -17676, -17496, -17487, -17482, -17468, -17454, -17433, -17427, -17417, -17202, -17185, -16983, -16970, -16942, -16915, -16733,
-16708, -16706, -16689, -16664, -16657, -16647, -16474, -16470, -16465, -16459, -16452, -16448, -16433, -16429, -16427, -16423, -16419,
-16412, -16407, -16403, -16401, -16393, -16220, -16216, -16212, -16205, -16202, -16187, -16180, -16171, -16169, -16158, -16155, -15959,
-15958, -15944, -15933, -15920, -15915, -15903, -15889, -15878, -15707, -15701, -15681, -15667, -15661, -15659, -15652, -15640, -15631,
-15625, -15454, -15448, -15436, -15435, -15419, -15416, -15408, -15394, -15385, -15377, -15375, -15369, -15363, -15362, -15183, -15180,
-15165, -15158, -15153, -15150, -15149, -15144, -15143, -15141, -15140, -15139, -15128, -15121, -15119, -15117, -15110, -15109, -14941,
-14937, -14933, -14930, -14929, -14928, -14926, -14922, -14921, -14914, -14908, -14902, -14894, -14889, -14882, -14873, -14871, -14857,
-14678, -14674, -14670, -14668, -14663, -14654, -14645, -14630, -14594, -14429, -14407, -14399, -14384, -14379, -14368, -14355, -14353,
-14345, -14170, -14159, -14151, -14149, -14145, -14140, -14137, -14135, -14125, -14123, -14122, -14112, -14109, -14099, -14097, -14094,
-14092, -14090, -14087, -14083, -13917, -13914, -13910, -13907, -13906, -13905, -13896, -13894, -13878, -13870, -13859, -13847, -13831,
-13658, -13611, -13601, -13406, -13404, -13400, -13398, -13395, -13391, -13387, -13383, -13367, -13359, -13356, -13343, -13340, -13329,
-13326, -13318, -13147, -13138, -13120, -13107, -13096, -13095, -13091, -13076, -13068, -13063, -13060, -12888, -12875, -12871, -12860,
-12858, -12852, -12849, -12838, -12831, -12829, -12812, -12802, -12607, -12597, -12594, -12585, -12556, -12359, -12346, -12320, -12300,
-12120, -12099, -12089, -12074, -12067, -12058, -12039, -11867, -11861, -11847, -11831, -11798, -11781, -11604, -11589, -11536, -11358,
-11340, -11339, -11324, -11303, -11097, -11077, -11067, -11055, -11052, -11045, -11041, -11038, -11024, -11020, -11019, -11018, -11014,
-10838, -10832, -10815, -10800, -10790, -10780, -10764, -10587, -10544, -10533, -10519, -10331, -10329, -10328, -10322, -10315, -10309,
-10307, -10296, -10281, -10274, -10270, -10262, -10260, -10256, -10254};
public static String[] pystr = new String[] {"a", "ai", "an", "ang", "ao", "ba", "bai", "ban", "bang", "bao", "bei", "ben", "beng", "bi", "bian",
"biao", "bie", "bin", "bing", "bo", "bu", "ca", "cai", "can", "cang", "cao", "ce", "ceng", "cha", "chai", "chan", "chang", "chao", "che",
"chen", "cheng", "chi", "chong", "chou", "chu", "chuai", "chuan", "chuang", "chui", "chun", "chuo", "ci", "cong", "cou", "cu", "cuan",
"cui", "cun", "cuo", "da", "dai", "dan", "dang", "dao", "de", "deng", "di", "dian", "diao", "die", "ding", "diu", "dong", "dou", "du",
"duan", "dui", "dun", "duo", "e", "en", "er", "fa", "fan", "fang", "fei", "fen", "feng", "fo", "fou", "fu", "ga", "gai", "gan", "gang",
"gao", "ge", "gei", "gen", "geng", "gong", "gou", "gu", "gua", "guai", "guan", "guang", "gui", "gun", "guo", "ha", "hai", "han", "hang",
"hao", "he", "hei", "hen", "heng", "hong", "hou", "hu", "hua", "huai", "huan", "huang", "hui", "hun", "huo", "ji", "jia", "jian",
"jiang", "jiao", "jie", "jin", "jing", "jiong", "jiu", "ju", "juan", "jue", "jun", "ka", "kai", "kan", "kang", "kao", "ke", "ken",
"keng", "kong", "kou", "ku", "kua", "kuai", "kuan", "kuang", "kui", "kun", "kuo", "la", "lai", "lan", "lang", "lao", "le", "lei", "leng",
"li", "lia", "lian", "liang", "liao", "lie", "lin", "ling", "liu", "long", "lou", "lu", "lv", "luan", "lue", "lun", "luo", "ma", "mai",
"man", "mang", "mao", "me", "mei", "men", "meng", "mi", "mian", "miao", "mie", "min", "ming", "miu", "mo", "mou", "mu", "na", "nai",
"nan", "nang", "nao", "ne", "nei", "nen", "neng", "ni", "nian", "niang", "niao", "nie", "nin", "ning", "niu", "nong", "nu", "nv", "nuan",
"nue", "nuo", "o", "ou", "pa", "pai", "pan", "pang", "pao", "pei", "pen", "peng", "pi", "pian", "piao", "pie", "pin", "ping", "po", "pu",
"qi", "qia", "qian", "qiang", "qiao", "qie", "qin", "qing", "qiong", "qiu", "qu", "quan", "que", "qun", "ran", "rang", "rao", "re",
"ren", "reng", "ri", "rong", "rou", "ru", "ruan", "rui", "run", "ruo", "sa", "sai", "san", "sang", "sao", "se", "sen", "seng", "sha",
"shai", "shan", "shang", "shao", "she", "shen", "sheng", "shi", "shou", "shu", "shua", "shuai", "shuan", "shuang", "shui", "shun",
"shuo", "si", "song", "sou", "su", "suan", "sui", "sun", "suo", "ta", "tai", "tan", "tang", "tao", "te", "teng", "ti", "tian", "tiao",
"tie", "ting", "tong", "tou", "tu", "tuan", "tui", "tun", "tuo", "wa", "wai", "wan", "wang", "wei", "wen", "weng", "wo", "wu", "xi",
"xia", "xian", "xiang", "xiao", "xie", "xin", "xing", "xiong", "xiu", "xu", "xuan", "xue", "xun", "ya", "yan", "yang", "yao", "ye", "yi",
"yin", "ying", "yo", "yong", "you", "yu", "yuan", "yue", "yun", "za", "zai", "zan", "zang", "zao", "ze", "zei", "zen", "zeng", "zha",
"zhai", "zhan", "zhang", "zhao", "zhe", "zhen", "zheng", "zhi", "zhong", "zhou", "zhu", "zhua", "zhuai", "zhuan", "zhuang", "zhui",
"zhun", "zhuo", "zi", "zong", "zou", "zu", "zuan", "zui", "zun", "zuo"};
private StringBuilder buffer;
private String resource;
private static CharacterParser characterParser = new CharacterParser();
public static CharacterParser getInstance() {
return characterParser;
}
public String getResource() {
return resource;
}
public void setResource(String resource) {
this.resource = resource;
}
/** * 汉字转成ASCII码 * * @param chs * @return */
private int getChsAscii(String chs) {
int asc = 0;
try {
byte[] bytes = chs.getBytes("gb2312");
if (bytes == null || bytes.length > 2 || bytes.length <= 0) {
throw new RuntimeException("illegal resource string");
}
if (bytes.length == 1) {
asc = bytes[0];
}
if (bytes.length == 2) {
int hightByte = 256 + bytes[0];
int lowByte = 256 + bytes[1];
asc = (256 * hightByte + lowByte) - 256 * 256;
}
} catch (Exception e) {
System.out.println("ERROR:ChineseSpelling.class-getChsAscii(String chs)" + e);
}
return asc;
}
/** * 单字解析 * * @param str * @return */
public String convert(String str) {
String result = null;
int ascii = getChsAscii(str);
if (ascii > 0 && ascii < 160) {
result = String.valueOf((char) ascii);
} else {
for (int i = (pyvalue.length - 1); i >= 0; i--) {
if (pyvalue[i] <= ascii) {
result = pystr[i];
break;
}
}
}
return result;
}
/** * 词组解析 * * @param chs * @return */
public String getSpelling(String chs) {
String key, value;
buffer = new StringBuilder();
for (int i = 0; i < chs.length(); i++) {
key = chs.substring(i, i + 1);
if (key.getBytes().length >= 2) {
value = (String) convert(key);
if (value == null) {
value = "unknown";
}
} else {
value = key;
}
buffer.append(value);
}
return buffer.toString();
}
public String getSpelling() {
return this.getSpelling(this.getResource());
}
}
我们顺着getSpelling(String chs)走，每次传进来一个字符串，他把每个字符都检出来，如果“utf-8”的编码长度大于等于2，证明它是汉字，调用convert（key）方法，获取他的拼音值，如果长度小于2，证明它不是汉字，直接获取值，然后就这样一个一个组合成字符串的拼音值。
convert（key）方法是如何获取汉字的拼音值的呢？int ascii = getChsAscii(str); 它通过这个获取到ascii（实际上应该是gb2312的编码值，作者写成acsii值，实在有点误人子弟），然后去对照两个大数组，通过ascii值来对应自己的拼音。
问题又来了，getChsAscii(str)是如何获取到gb2312的编码值的呢？看官且往下看，如果传入字符的gb码长度是1的话，那么肯定不是汉字，直接输出，如果长度大于1的话，那么是汉字，然后通过String.getBytes()获取它的高八位，和低八位，各加一个256还原成他们本来的“：高字节的值为0xA0+区号，低字节的值为0xA0+位号”，然后通过高八位*256+低八位获取到他们原始的编码值，这个值已经是唯一的了，此时作者画蛇已成，显然有点飘飘然，欣欣然地加上了一句：-256*256，于是所有的值都变成负数了，然后害得如果你是东北人，就可能要“寻思”一番了。
到此为止，输入一个汉字，我们应该了解了是如何得到一个汉字了，以上只是作者对于“一级汉字”的支持，二级汉字显然是处理麻烦了一些，完全可以实现，但是需要很多判断，如果您想拓展到此完全可以自己实现了。
接下来就是往列表中加载数据了，当然用到的是android最经典的adapter，来看我们的adpater类：
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) {
final SortModel mContent = list.get(position);
View rootView = LayoutInflater.from(mContext).inflate(R.layout.bluet_contract_item, arg2,false);
TextView tvTitle = (TextView) rootView.findViewById(R.id.title);
TextView tvLetter = (TextView) rootView.findViewById(R.id.catalog);
//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)){
tvLetter.setVisibility(View.VISIBLE);
tvLetter.setText(mContent.getSortLetters());
}else{
tvLetter.setVisibility(View.GONE);
}
tvTitle.setText(this.list.get(position).getName());
return rootView;
}
/**
* 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;
}
传入参数为一个根据拼音首字母排序好了的列表，泛型为SortModel的类型，getview()进行渲染时候，每到一个position，就获取对应项的首字母，然后查这个首字母在列表的位置，如果此position等于彼position，然后证明这个是第一个携带该首字母出现的，然后在布局中把"ABCDEF"之类的字母显示出来，如果不等于，那么就只显示数据了。
顺便发下布局文件和SortModel类
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:orientation="vertical" >
<TextView
android:id="@+id/catalog"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#E0E0E0"
android:textColor="#454545"
android:layout_weight="1.0"
android:paddingLeft="5dip"
android:paddingTop="5dip"
android:paddingBottom="5dip"
/>
<TextView
android:id="@+id/title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:layout_weight="1.0"
android:textColor="#336598"
android:layout_marginLeft="5dip"
android:paddingTop="10dip"
android:paddingBottom="10dip"
/>
</LinearLayout>
public class SortModel {
private String name; //显示的数据
private String sortLetters; //显示数据拼音的字母
private String phoneNumber;//联系人的手机号
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 String getPhoneNumber() {
return phoneNumber;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
}
然后我们来看看主页面加载的时候，是如何把初始的数据按次序加载到列表上的。
public class BluetoothFragment extends Fragment{
private ListView telephonyListView;
private SideBar sideBar;
/**
* 汉字转换成拼音
*/
private CharacterParser characterParser;
private List<SortModel> SourceDateList; // 联系人列表填充数据
private SortAdapter contractsAdapter;// 联系人列表适配器
/**
* 根据拼音来排列ListView里面的数据类
*/
private PinyinComparator pinyinComparator;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// TODO Auto-generated method stub
telephonyListView = (ListView) view.findViewById(R.id.bluet_telephony_listview);
String[] nameStrings = new String[]{"明明","刚刚","军军","红红","花花","冷冷","妍妍","特特","贝贝","爱爱","怜怜","采采"};
String[] phoneStrings = new String[]{"19837472999","15884578834","34567866643","12343254323","34521233367","34512322213","65432344456","34567866643","12343254323","34521233367","34512322213","65432344456"};
SourceDateList = filledData(nameStrings,phoneStrings);
Collections.sort(SourceDateList,pinyinComparator);
contractsAdapter = new SortAdapter(getActivity(),SourceDateList);
telephonyListView.setAdapter(contractsAdapter);
}
/**
* 为ListView填充数据
*
* @param data
* @param phoneNumber
* @return
*/
private List<SortModel> filledData(String[] data, String[] phoneNumber) {
List<SortModel> mSortList = new ArrayList<SortModel>();
for (int i = 0; i < data.length; i++) {
SortModel sortModel = new SortModel();
sortModel.setName(data[i]);
sortModel.setPhoneNumber(phoneNumber[i]);
// 汉字转换成拼音
String pinyin = characterParser.getSpelling(data[i]);
String sortString = pinyin.substring(0, 1).toUpperCase(Locale.getDefault());
// 正则表达式，判断首字母是否是英文字母
if (sortString.matches("[A-Z]")) {
sortModel.setSortLetters(sortString.toUpperCase(Locale.getDefault()));
} else {
sortModel.setSortLetters("#");
}
mSortList.add(sortModel);
}
return mSortList;
}
}
初始数据通过filledData()组成一个list，里边是一个一个的sortmodel，通过对name属性得到拼音，再得到首字母，然后用到一个正则表达式match("[A-Z]"),如果首字母是a-z的字符，则把该sortmodel对象的sortLetters属性设为原字符，否则就设为 "#"，好了list创建完毕了，但是要适配的adapter上，还需要，还需要什么？对！就是我们的排序，这里又用到了我们的PinyinComparator工具类：
public class PinyinComparator implements Comparator<SortModel> {
public int compare(SortModel o1, SortModel o2) {
//这里主要是用来对ListView里面的数据根据ABCDEFG...来排序
if (o2.getSortLetters().equals("#")) {
return -1;
} else if (o1.getSortLetters().equals("#")) {
return 1;
} else {
return o1.getSortLetters().compareTo(o2.getSortLetters());
}
}
}
Comparator的原理就是运用compare的返回值来比较前后两者的大小，返回负值说明前者的小于后者，返回正值说明前者大于后者，返回0证明两者相等，原生的compare方法总是通过unicode码比较两者大小，排序后的列表是按照升序排列的。
到此为止，我们的列表部分算是已经完成了。
接下来看看我们的自定义组件SideBar
public class SideBar extends View {
// 触摸事件
private OnTouchingLetterChangedListener onTouchingLetterChangedListener;
// 26个字母
public static String[] b = { "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", "#" };
private int choose = -1;// 选中
private Paint paint = new Paint();
private TextView mTextDialog;
/**
* 为SideBar设置显示字母的TextView
* @param mTextDialog
*/
public void setTextView(TextView mTextDialog) {
this.mTextDialog = mTextDialog;
}
public SideBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public SideBar(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SideBar(Context context) {
super(context);
}
/**
* 重写这个方法
*/
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// 获取焦点改变背景颜色.
int height = getHeight();// 获取对应高度
int width = getWidth(); // 获取对应宽度
int singleHeight = height / b.length;// 获取每一个字母的高度
for (int i = 0; i < b.length; i++) {
paint.setColor(Color.rgb(33, 65, 98));
// paint.setColor(Color.WHITE);
paint.setTypeface(Typeface.DEFAULT_BOLD);
paint.setAntiAlias(true);
paint.setTextSize(12);
// 选中的状态
if (i == choose) {
paint.setColor(Color.parseColor("#3399ff"));
paint.setFakeBoldText(true);
}
// x坐标等于中间-字符串宽度的一半.
float xPos = width / 2 - paint.measureText(b[i]) / 2;
float yPos = singleHeight * i + singleHeight;
canvas.drawText(b[i], xPos, yPos, paint);
paint.reset();// 重置画笔
}
}
@SuppressLint("NewApi")
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
final int action = event.getAction();
final float y = event.getY();// 点击y坐标
final int oldChoose = choose;
final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;
final int c = (int) (y / getHeight() * b.length);// 点击y坐标所占总高度的比例*b数组的长度就等于点击b中的个数.
switch (action) {
case MotionEvent.ACTION_UP:
setBackgroundDrawable(new ColorDrawable(0x00000000));
choose = -1;//
invalidate();
if (mTextDialog != null) {
mTextDialog.setVisibility(View.INVISIBLE);
}
break;
default:
setBackground(new ColorDrawable(Color.MAGENTA));
if (oldChoose != c) {
if (c >= 0 && c < b.length) {
if (listener != null) {
listener.onTouchingLetterChanged(b[c]);
}
if (mTextDialog != null) {
mTextDialog.setText(b[c]);
mTextDialog.setVisibility(View.VISIBLE);
}
choose = c;
invalidate();
}
}
break;
}
return true;
}
/**
* 向外公开的方法
*
* @param onTouchingLetterChangedListener
*/
public void setOnTouchingLetterChangedListener(
OnTouchingLetterChangedListener onTouchingLetterChangedListener) {
this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;
}
/**
* 接口
*
* @author coder
*
*/
public interface OnTouchingLetterChangedListener {
public void onTouchingLetterChanged(String s);
}
}
这个sidebar只是重写了ondraw和dispatchTouchEvent方法，其实对于一个不是viewgroup的view来说，因为不涉及给子View分配ontouch事件的逻辑，重写dispatchTouchEvent和ontouch方法其实是一样的，而且本次重写会多次在dispatchTouchEvent中调用invalidate方法调用ondraw，我们就先来分析这个invalidate方法：
我在触摸屏幕没有松开手指走到“default:”这个地方，如果我触摸的区域不是原来的字母区域，这时候我如果绑定了listener的话，会做回调listener中的方法的操作， 如果你为这个sidebar绑定了textview，他还要控制textview的文字和显隐。final int c = (int) (y / getHeight() * b.length); 这个c值记录了当前触摸到的是哪一个字母，然后调用ondraw刷新view，如果你松开了手指，那就走到了case MotionEvent.ACTION_UP这里，然后把choose变成-1，刷新view，从这里我们其实可以猜出来，在ondraw中肯定是根据choose的值，去动态刷新view的，那么具体是怎么做的呢？
其实就是根据choose的值，在手指触摸到的那个字母上，改变画笔的属性，画出来和别的字母颜色不一样的字母罢了。
sideBar.setTextView(sideText);
// 设置右侧触摸监听
sideBar.setOnTouchingLetterChangedListener(new OnTouchingLetterChangedListener() {
@Override
public void onTouchingLetterChanged(String s) {
// 该字母首次出现的位置
if (contractsAdapter != null) {
int position = contractsAdapter.getPositionForSection(s.charAt(0));
if (position != -1) {
telephonyListView.setSelection(position);
}
}
}
});
其实刚才的fragment的oncreate方法中少写了上面的一段代码，是初始化sidebar用的，在listener中调用刷新列表的方法，然后我们就可以看到如文章开始时刻的画面了 >_<
by the way，您能看完这个博文，证明您已经很努力地再看了，以本人拙劣的表述还要写这么长的文章 是不是很捉急啊？
时间： 2024-10-17 10:00:29