网站开发需要，找了几个js脚本，最后选择了jQuery Autocomplete Mod（http://www.pengoworks.com/workshop/jquery/autocomplete.htm）
稍作修改，改动处见中文注释
1 jQuery.autocomplete = function(input, options) {
2 // Create a link to self
3 var me = this;
4
5 // Create jQuery object for input element
6 var $input = $(input).attr("autocomplete", "off");
7
8 // Apply inputClass if necessary
9 if (options.inputClass) $input.addClass(options.inputClass);
10
11 // Create results
12 var results = document.createElement("div");
13 // Create jQuery object for results
14 var $results = $(results);
15 $results.hide().addClass(options.resultsClass).css("position", "absolute");
16 if( options.width > 0 ) $results.css("width", options.width);
17
18 // Add to body element
19 $("body").append(results);
20
21 input.autocompleter = me;
22
23 var timeout = null;
24 var prev = "";
25 var active = -1;
26 var cache = {};
27 var keyb = false;
28 var hasFocus = false;
29 var lastKeyPressCode = null;
30
31 // flush cache
32 function flushCache(){
33 cache = {};
34 cache.data = {};
35 cache.length = 0;
36 };
37
38 // flush cache
39 flushCache();
40
41 // if there is a data array supplied
42 if( options.data != null ){
43 var sFirstChar = "", stMatchSets = {}, row = [];
44
45 // no url was specified, we need to adjust the cache length to make sure it fits the local data store
46 if( typeof options.url != "string" ) options.cacheLength = 1;
47
48 // loop through the array and create a lookup structure
49 for( var i=0; i < options.data.length; i++ ){
50 // if row is a string, make an array otherwise just reference the array
51 row = ((typeof options.data[i] == "string") ? [options.data[i]] : options.data[i]);
52
53 // if the length is zero, don't add to list
54 if( row[0].length > 0 ){
55 // get the first character
56 sFirstChar = row[0].substring(0, 1).toLowerCase();
57 // if no lookup array for this character exists, look it up now
58 if( !stMatchSets[sFirstChar] ) stMatchSets[sFirstChar] = [];
59 // if the match is a string
60 stMatchSets[sFirstChar].push(row);
61 }
62 }
63
64 // add the data items to the cache
65 for( var k in stMatchSets ){
66 // increase the cache size
67 options.cacheLength++;
68 // add to the cache
69 addToCache(k, stMatchSets[k]);
70 }
71 }
72
73 $input.keyup(function(e) {
74 // track last key pressed
75 lastKeyPressCode = e.keyCode;
76 switch(e.keyCode) {
77 case 38: // up
78 e.preventDefault();
79 moveSelect(-1);
80 break;
81 case 40: // down
82 e.preventDefault();
83 moveSelect(1);
84 break;
85 case 9: // tab
86 case 13: // return
87 if( selectCurrent() ){
88 // make sure to blur off the current field
89 $input.get(0).blur();
90 e.preventDefault();
91 }
92 break;
93 default:
94 active = -1;
95 if (timeout) clearTimeout(timeout);
96 timeout = setTimeout(function(){onChange();}, options.delay);
97 break;
98 }
99 })
100 .focus(function(){
101 // track whether the field has focus, we shouldn't process any results if the field no longer has focus
102 hasFocus = true;
103 })
104 .blur(function() {
105 // track whether the field has focus
106 hasFocus = false;
107 hideResults();
108 });
109
110 hideResultsNow();
111
112 function onChange() {
113 // ignore if the following keys are pressed: [del] [shift] [capslock]
114 if( lastKeyPressCode == 46 || (lastKeyPressCode > 8 && lastKeyPressCode < 32) ) return $results.hide();
115 var v = $input.val();
116 if (v == prev) return;
117 prev = v;
118 if (v.length >= options.minChars) {
119 $input.addClass(options.loadingClass);
120 requestData(v);
121 } else {
122 $input.removeClass(options.loadingClass);
123 $results.hide();
124 }
125 };
126
127 function moveSelect(step) {
128
129 var lis = $("li", results);
130 if (!lis) return;
131
132 active += step;
133
134 if (active < 0) {
135 active = 0;
136 } else if (active >= lis.size()) {
137 active = lis.size() - 1;
138 }
139
140 lis.removeClass("ac_over");
141
142 $(lis[active]).addClass("ac_over");
143
144 // Weird behaviour in IE
145 // if (lis[active] && lis[active].scrollIntoView) {
146 // lis[active].scrollIntoView(false);
147 // }
148
149 };
150
151 function selectCurrent() {
152 var li = $("li.ac_over", results)[0];
153 if (!li) {
154 var $li = $("li", results);
155 if (options.selectOnly) {
156 if ($li.length == 1) li = $li[0];
157 } else if (options.selectFirst) {
158 li = $li[0];
159 }
160 }
161 if (li) {
162 selectItem(li);
163 return true;
164 } else {
165 return false;
166 }
167 };
168
169 function selectItem(li) {
170 if (!li) {
171 li = document.createElement("li");
172 li.extra = [];
173 li.selectValue = "";
174 }
175 var v = $.trim(li.selectValue ? li.selectValue : li.innerHTML);
176 input.lastSelected = v;
177 prev = v;
178 $results.html("");
179 $input.val(v);
180 hideResultsNow();
181 if (options.onItemSelect) setTimeout(function() { options.onItemSelect(li) }, 1);
182 };
183
184 // selects a portion of the input string
185 function createSelection(start, end){
186 // get a reference to the input element
187 var field = $input.get(0);
188 if( field.createTextRange ){
189 var selRange = field.createTextRange();
190 selRange.collapse(true);
191 selRange.moveStart("character", start);
192 selRange.moveEnd("character", end);
193 selRange.select();
194 } else if( field.setSelectionRange ){
195 field.setSelectionRange(start, end);
196 } else {
197 if( field.selectionStart ){
198 field.selectionStart = start;
199 field.selectionEnd = end;
200 }
201 }
202 field.focus();
203 };
204
205 // fills in the input box w/the first match (assumed to be the best match)
206 function autoFill(sValue){
207 // if the last user key pressed was backspace, don't autofill
208 if( lastKeyPressCode != 8 ){
209 // fill in the value (keep the case the user has typed)
210 $input.val($input.val() + sValue.substring(prev.length));
211 // select the portion of the value not typed by the user (so the next character will erase)
212 createSelection(prev.length, sValue.length);
213 }
214 };
215
216 function showResults() {
217 // get the position of the input field right now (in case the DOM is shifted)
218 var pos = findPos(input);
219 // either use the specified width, or autocalculate based on form element
220 var iWidth = (options.width > 0) ? options.width : $input.width();
221 // reposition
222 $results.css({
223 width: parseInt(iWidth) + "px",
224 top: (pos.y + input.offsetHeight) + "px",
225 left: pos.x + "px"
226 }).show();
227 };
228
229 function hideResults() {
230 if (timeout) clearTimeout(timeout);
231 timeout = setTimeout(hideResultsNow, 200);
232 };
233
234 function hideResultsNow() {
235 if (timeout) clearTimeout(timeout);
236 $input.removeClass(options.loadingClass);
237 if ($results.is(":visible")) {
238 $results.hide();
239 }
240 if (options.mustMatch) {
241 var v = $input.val();
242 if (v != input.lastSelected) {
243 selectItem(null);
244 }
245 }
246 };
247
248 function receiveData(q, data) {
249 if (data) {
250 $input.removeClass(options.loadingClass);
251 results.innerHTML = "";
252
253 // if the field no longer has focus or if there are no matches, do not display the drop down
254 if( !hasFocus || data.length == 0 ) return hideResultsNow();
255
256 if ($.browser.msie) {
257 // we put a styled iframe behind the calendar so HTML SELECT elements don't show through
258 $results.append(document.createElement('iframe'));
259 }
260 results.appendChild(dataToDom(data));
261 // autofill in the complete box w/the first match as long as the user hasn't entered in more data
262 if( options.autoFill && ($input.val().toLowerCase() == q.toLowerCase()) ) autoFill(data[0][0]);
263 showResults();
264 } else {
265 hideResultsNow();
266 }
267 };
268
269 function parseData(data) {
270 if (!data) return null;
271 var parsed = [];
272 var rows = data.split(options.lineSeparator);
273 for (var i=0; i < rows.length; i++) {
274 var row = $.trim(rows[i]);
275 if (row) {
276 parsed[parsed.length] = row.split(options.cellSeparator);
277 }
278 }
279 return parsed;
280 };
281
282 function dataToDom(data) {
283 var ul = document.createElement("ul");
284 var num = data.length;
285
286 // limited results to a max number
287 if( (options.maxItemsToShow > 0) && (options.maxItemsToShow < num) ) num = options.maxItemsToShow;
288
289 for (var i=0; i < num; i++) {
290 var row = data[i];
291 if (!row) continue;
292 var li = document.createElement("li");
293 if (options.formatItem) {
294 li.innerHTML = options.formatItem(row, i, num);
295 li.selectValue = row[0];
296 } else {
297 li.innerHTML = row[0];
298 li.selectValue = row[0];
299 }
300 /*var extra = null;
301 if (row.length > 1) {
302 extra = [];
303 for (var j=1; j < row.length; j++) {
304 extra[extra.length] = row[j];
305 }
306 }
307 li.extra = extra;*/
308 ul.appendChild(li);
309 $(li).hover(
310 function() { $("li", ul).removeClass("ac_over"); $(this).addClass("ac_over"); active = $("li", ul).indexOf($(this).get(0)); },
311 function() { $(this).removeClass("ac_over"); }
312 ).click(function(e) { e.preventDefault(); e.stopPropagation(); selectItem(this) });
313 }
314 return ul;
315 };
316
317 function requestData(q) {
318 if (!options.matchCase) q = q.toLowerCase();
319 var data = options.cacheLength ? loadFromCache(q) : null;
320 // recieve the cached data
321 if (data) {
322 receiveData(q, data);
323 // if an AJAX url has been supplied, try loading the data now
324 } else if( (typeof options.url == "string") && (options.url.length > 0) ){
325 $.get(makeUrl(q), function(data) {
326 data=data[options.returnParam];//指定返回参数名，written by HanJunyi
327 data = parseData(data);
328 addToCache(q, data);
329 receiveData(q, data);
330 });
331 // if there's been no data found, remove the loading class
332 } else {
333 $input.removeClass(options.loadingClass);
334 }
335 };
336
337 function makeUrl(q) {
338 var url = options.url + "?q=" + encodeURI(q);
339 for (var i in options.extraParams) {
340 url += "&" + i + "=" + encodeURI(options.extraParams[i]);
341 }
342 return url;
343 };
344
345 function loadFromCache(q) {
346 if (!q) return null;
347 if (cache.data[q]) return cache.data[q];
348 if (options.matchSubset) {
349 for (var i = q.length - 1; i >= options.minChars; i--) {
350 var qs = q.substr(0, i);
351 var c = cache.data[qs];
352 if (c) {
353 var csub = [];
354 for (var j = 0; j < c.length; j++) {
355 var x = c[j];
356 var x0 = x[0];
357 if (matchSubset(x0, q)) {
358 csub[csub.length] = x;
359 }
360 }
361 return csub;
362 }
363 }
364 }
365 return null;
366 };
367
368 function matchSubset(s, sub) {
369 if (!options.matchCase) s = s.toLowerCase();
370 var i = s.indexOf(sub);
371 if (i == -1) return false;
372 return i == 0 || options.matchContains;
373 };
374
375 this.flushCache = function() {
376 flushCache();
377 };
378
379 this.setExtraParams = function(p) {
380 options.extraParams = p;
381 };
382
383 this.findValue = function(){
384 var q = $input.val();
385
386 if (!options.matchCase) q = q.toLowerCase();
387 var data = options.cacheLength ? loadFromCache(q) : null;
388 if (data) {
389 findValueCallback(q, data);
390 } else if( (typeof options.url == "string") && (options.url.length > 0) ){
391 $.get(makeUrl(q), function(data) {
392 data = parseData(data)
393 addToCache(q, data);
394 findValueCallback(q, data);
395 });
396 } else {
397 // no matches
398 findValueCallback(q, null);
399 }
400 }
401
402 function findValueCallback(q, data){
403 if (data) $input.removeClass(options.loadingClass);
404
405 var num = (data) ? data.length : 0;
406 var li = null;
407
408 for (var i=0; i < num; i++) {
409 var row = data[i];
410
411 if( row[0].toLowerCase() == q.toLowerCase() ){
412 li = document.createElement("li");
413 if (options.formatItem) {
414 li.innerHTML = options.formatItem(row, i, num);
415 li.selectValue = row[0];
416 } else {
417 li.innerHTML = row[0];
418 li.selectValue = row[0];
419 }
420 var extra = null;
421 if( row.length > 1 ){
422 extra = [];
423 for (var j=1; j < row.length; j++) {
424 extra[extra.length] = row[j];
425 }
426 }
427 li.extra = extra;
428 }
429 }
430
431 if( options.onFindValue ) setTimeout(function() { options.onFindValue(li) }, 1);
432 }
433
434 function addToCache(q, data) {
435 if (!data || !q || !options.cacheLength) return;
436 if (!cache.length || cache.length > options.cacheLength) {
437 flushCache();
438 cache.length++;
439 } else if (!cache[q]) {
440 cache.length++;
441 }
442 cache.data[q] = data;
443 };
444
445 function findPos(obj) {
446 var curleft = obj.offsetLeft || 0;
447 var curtop = obj.offsetTop || 0;
448 while (obj = obj.offsetParent) {
449 curleft += obj.offsetLeft
450 curtop += obj.offsetTop
451 }
452 return {x:curleft,y:curtop};
453 }
454 }
455
456 jQuery.fn.autocomplete = function(url, options, data) {
457 // Make sure options exists
458 options = options || {};
459 // Set url as option
460 options.url = url;
461 // set some bulk local data
462 options.data = ((typeof data == "object") && (data.constructor == Array)) ? data : null;
463
464 // Set default values for required options
465 options.inputClass = options.inputClass || "ac_input";
466 options.resultsClass = options.resultsClass || "ac_results";
467 options.lineSeparator = options.lineSeparator || "\n";
468 options.cellSeparator = options.cellSeparator || "|";
469 options.minChars = options.minChars || 1;
470 options.delay = options.delay || 400;
471 options.matchCase = options.matchCase || 0;
472 options.matchSubset = options.matchSubset || 1;
473 options.matchContains = options.matchContains || 0;
474 options.cacheLength = options.cacheLength || 1;
475 options.mustMatch = options.mustMatch || 0;
476 options.extraParams = options.extraParams || {};
477 options.loadingClass = options.loadingClass || "ac_loading";
478 options.selectFirst = options.selectFirst || false;
479 options.selectOnly = options.selectOnly || false;
480 options.maxItemsToShow = options.maxItemsToShow || -1;
481 options.autoFill = options.autoFill || false;
482 options.width = parseInt(options.width, 10) || 0;
483 options.returnParam=options.returnParam||"";//指定返回参数名，written by HanJunyi
484
485 this.each(function() {
486 var input = this;
487 new jQuery.autocomplete(input, options);
488 });
489
490 // Don't break the chain
491 return this;
492 }
493
494 jQuery.fn.autocompleteArray = function(data, options) {
495 return this.autocomplete(null, options, data);
496 }
497
498 jQuery.fn.indexOf = function(e){
499 for( var i=0; i<this.length; i++ ){
500 if( this[i] == e ) return i;
501 }
502 return -1;
503 };
在页面中就这么用啦
$("#文本框id").autocomplete(url,{
minChars:3,//用户至少需要输入三个字符数
returnParam:"userList",//返回参数名
formatItem: function(row, i, max) {
return i+1 + ":" + row[0] + "[" + row[1] + "]";
}
});
另：输入中文时自动完成功能总是用不了，alert下e.keyCode,发现抓取到的keycode总是229.Bing下找到这篇文章（http://aspok.net/html/jishuwenzhang/JavaScriptjishu/33.Html），将73行的$input.keydown改成$input.keyup就行了。
自动完成功能初步搞定。