最近因项目中要用，于是就扩展了TextBox实现输入汉字首字母简单查询。控件扩展代码很简单。但是刚开始，一直没有找到扩展入口，始终无法展现下拉框。先想通过AutoCompleteCustomSource属性改变来实现，但最终没法扩展。后又想到ComboBox但是，也不好控制。经过一天的思考后决定用TextBox + ListBox组合扩展（主要为继承至TextBox和持有ListBox；
效果先上：
最要实现代码有：
类原型public class SpellSearchBoxEx : TextBox
{
private ListBox searchList;
.....
1：
SpellSearchSource ：查询数据源（汉字）
事件的绑定和选择全在属性里；
public string[] SpellSearchSource
{
get { return source; }
set
{
if (value != null)
{
source = value;
InitSourceSpell();//实现数据转化为相应拼音并存储；
TextChanged += new EventHandler(SpellSearchBoxEx_TextChanged);
LostFocus += new EventHandler(SpellSearchBoxEx_LostFocus);
// searchList是一个ListBox，它用来显示下拉框；
searchList.KeyDown += new KeyEventHandler(searchList_KeyDown);
searchList.Click += new EventHandler(searchList_Click);
searchList.MouseMove += new MouseEventHandler(searchList_MouseMove);
}
}
}
2：TextChanged事件代码
protected virtual void SpellSearchBoxEx_TextChanged(object sender, EventArgs e)
{
searchList.Items.Clear();
string str = this.Text;
foreach (string var in spellList)
{
if (SearchMode == SearchMode.Contains)
{
if (var.IndexOf(str.ToUpper()) != -1)
{
searchList.Items.Add(source[spellList.IndexOf(var)]);
}
}
else
{
if (var.ToUpper().StartsWith(str.ToUpper()))
{
for (int i = 0; i < spellList.Count; i++)
{
if (spellList[i].Equals(var) && !searchList.Items.Contains(source[i]))
{
searchList.Items.Add(source[i]);
}
}
}
}
}
if (Regex.IsMatch(str, "[\u4e00-\u9fa5]+"))
{
foreach (string var in source)
{
if (SearchMode == SearchMode.Contains)
{
if (var.ToUpper().IndexOf(str.ToUpper()) != -1 && !searchList.Items.Contains(var))
{
searchList.Items.Add(var);
}
}
else
{
if (var.ToUpper().StartsWith(str.ToUpper()) && !searchList.Items.Contains(var))
{
searchList.Items.Add(var);
}
}
}
}
SetSearchBoxState();
}
3：控制ListBox的显示和隐藏
private void SetSearchBoxState()
{
if (searchList.Items.Count > 0)
{
searchList.BorderStyle = BorderStyle.FixedSingle;
// maxItemCount为下拉框最大显示数；
searchList.Height = ((searchList.Items.Count >= maxItemCount ? maxItemCount : searchList.Items.Count) + 1) * searchList.ItemHeight;
searchList.Parent = this.Parent;
searchList.Location = new System.Drawing.Point(this.Left, this.Bottom);
searchList.Width = this.Width;
searchList.BringToFront();
searchList.Visible = true;
}
else
{
searchList.Visible = false;
}
}
4：剩下的为：控制鼠标滑动和键盘方向键操作，很简单，主要利用ListBox的选中项为高亮显示；及在textBox LostFocus 并非ListBox获得焦点时隐藏结果控件ListBox
5：
ListBox上回车或者是点击时提交代码
protected virtual void CommitSearchList()
{
if (searchList.SelectedIndex > -1)
{
this.Text = searchList.Items[searchList.SelectedIndex].ToString();
searchList.Visible = false;
this.Focus();
}
}
6：主体汉字检索拼音转化代码，见下：很简单，可以直接复制拿来用。
代码
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace GroupControl.SplitWord
{
/// 用C#实现汉字转化为拼音
/// 实现的原理就是先将汉字转化成为内码，然后通过内码和拼音的对照来查找。
public class SplitWord
{
/// <summary>
///将所有的汉字转换成为拼音（小写）
/// </summary>
static Regex MyRegex = new Regex("^[\u4e00-\u9fa5]$"); //汉字的正则表达式.eg: if(MyRegex.IsMatch(chrstr.ToString()))
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};
private 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"};
/**/
/// <summary>
/// 转化汉字的全部拼音
/// </summary>
/// <param name="chrstr"></param>
/// <returns></returns>
public static string ConvertAllSpell(string chrstr)
{
Regex MyRegex = new Regex("^[一-龥]$");
byte[] array = new byte[2];
string returnstr = "";
int chrasc = 0;
int i1 = 0;
int i2 = 0;
char[] nowchar = chrstr.ToCharArray();
for (int j = 0; j < nowchar.Length; j++)
{
if (MyRegex.IsMatch(nowchar[j].ToString()))
{
array = System.Text.Encoding.Default.GetBytes(nowchar[j].ToString());
i1 = (short)(array[0]);
i2 = (short)(array[1]);
chrasc = i1 * 256 + i2 - 65536;
if (chrasc > 0 && chrasc < 160)
{
returnstr += nowchar[j];
}
else
{
for (int i = (pyvalue.Length - 1); i >= 0; i--)
{
if (pyvalue[i] <= chrasc)
{
returnstr += pystr[i];
break;
}
}
}
}
else
{
returnstr += nowchar[j].ToString();
}
}
return returnstr;
}
//ChineseToPY
/**/
/// <summary>
/// 只转换每个汉字首字母（大写）
/// </summary>
/// <param name="strText"></param>
/// <returns></returns>
public static string GetChineseSpell(string strText)
{
int len = strText.Length;
string myStr = "";
for (int i = 0; i < len; i++)
{
myStr += getSpell(strText.Substring(i, 1));
}
return myStr;
}
/// <summary>
/// 获得第一个汉字的首字母（大写）；
/// </summary>
/// <param name="cnChar"></param>
/// <returns></returns>
public static string getSpell(string cnChar)
{
byte[] arrCN = Encoding.Default.GetBytes(cnChar);
if (arrCN.Length > 1)
{
int area = (short)arrCN[0];
int pos = (short)arrCN[1];
int code = (area << 8) + pos;
int[] areacode ={ 45217, 45253, 45761, 46318, 46826, 47010, 47297, 47614, 48119, 48119, 49062, 49324, 49896, 50371, 50614, 50622, 50906, 51387, 51446, 52218, 52698, 52698, 52698, 52980, 53689, 54481 };
for (int i = 0; i < 26; i++)
{
int max = 55290;
if (i != 25) max = areacode[i + 1];
if (areacode[i] <= code && code < max)
{
return Encoding.Default.GetString(new byte[] { (byte)(65 + i) });
}
}
return "*";
}
else return cnChar;
}
}
}