Ajax效果的字符串過濾

2012/11/12 13:00:08作者：佚名來源：網(wǎng)絡(luò)

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【實(shí)例名稱】

Ajax效果的字符串過濾

【實(shí)例描述】

在Microsoft提供的Ajax框架中，有個(gè)根據(jù)第一個(gè)字母選擇單詞的過濾實(shí)例。本例將學(xué)習(xí)如何使用正則實(shí)現(xiàn)這種效果。

【實(shí)例代碼】

<HTML><HEAD><TITLE>過濾字符實(shí)例-學(xué)無憂（www.wangbatian.cn）</title>
<script type="text/javascript">
function filterlist(selectobj) {
  // 過濾對象
  this.selectobj = selectobj;
  //要過濾得字符-i表示忽略大小寫，""表示不忽略
  this.flags = 'i';
  // 要過濾的項(xiàng)-選擇是文本還是值
  this.match_text = true;
  this.match_value = false; 
  //調(diào)試參數(shù)
  this.show_debug = false;
  //初始化的方法
  this.init = function() {
    if (!this.selectobj) return this.debug('沒有實(shí)現(xiàn)過濾的控件');
    if (!this.selectobj.options) return this.debug('過濾控件中沒有內(nèi)容');
    //制作選擇項(xiàng)的副本
    this.optionscopy = new Array();
    if (this.selectobj && this.selectobj.options) {
      for (var i=0; i < this.selectobj.options.length; i++) {
        // 創(chuàng)建一個(gè)新的選擇項(xiàng)對象
        this.optionscopy[i] = new Option();
        // 設(shè)置選擇項(xiàng)的文本
        this.optionscopy[i].text = selectobj.options[i].text;
        // 設(shè)置選擇項(xiàng)的值
        if (selectobj.options[i].value) {
          this.optionscopy[i].value = selectobj.options[i].value;
        } else {
          this.optionscopy[i].value = selectobj.options[i].text;
        }
      }
    }
  }
  this.reset = function() {   //重置選擇項(xiàng)
    this.set('');
  }
   //實(shí)現(xiàn)過濾的方法
  this.set = function(pattern) {
    var loop=0, index=0, regexp, e;
    if (!this.selectobj) return this.debug('沒有實(shí)現(xiàn)過濾的控件');
    if (!this.selectobj.options) return this.debug('過濾控件中沒有內(nèi)容');
    // 清空列表中的內(nèi)容
    this.selectobj.options.length = 0;
    // 使用正則實(shí)現(xiàn)字符過濾-初始化正則
    try {
      regexp = new RegExp(pattern, this.flags);
    } catch(e) {
      if (typeof this.hook == 'function') {
        this.hook();
      }
      return;
    }
    // 循環(huán)添加過濾后的結(jié)果
    for (loop=0; loop < this.optionscopy.length; loop++) {
      // 定義選擇項(xiàng)
      var option = this.optionscopy[loop];
      // 實(shí)現(xiàn)正則式過濾
      if ((this.match_text && regexp.test(option.text)) ||
          (this.match_value && regexp.test(option.value))) {
        // 使用過濾結(jié)果創(chuàng)建新選擇項(xiàng)
        this.selectobj.options[index++] =
          new Option(option.text, option.value, false);
      }
    }
    if (typeof this.hook == 'function') {
      this.hook();
    }
  }
  //設(shè)置正則表達(dá)式的過濾標(biāo)志
  this.set_ignore_case = function(value) {
    if (value) {
      this.flags = 'i';
    } else {
      this.flags = '';
    }
  }
  this.debug = function(msg) {    //調(diào)試方法   
    if (this.show_debug) {
      alert('過濾結(jié)果: ' + msg);
    }
  }
  this.init();                        //調(diào)用初始化方法
}
</script>
</HEAD>
<BODY>
<H1>過濾字符實(shí)例</H1>
<FORM name=myform action=""><SELECT size=5 name=myselect> <OPTION>Aefdf 
  Rsses<OPTION>Lbadmn Adjlf<OPTION>Monica Betty<OPTION>Daniel 
  Jack<OPTION>Bill Gayes<OPTION>Lama Tampel<OPTION>Natty
  Lees<OPTION>Harry J. Leoo<OPTION>Matty McColm<OPTION>Carrie-Anne 
  Moss<OPTION>Collin Chou<OPTION>Genevieve O'Reilly<OPTION>Harold Perrineau 
  Jr.<OPTION>Jada Pinkett Smith<OPTION>Adrian Rayment<OPTION>Neil 
  Rayment<OPTION>Bruce Spence<OPTION>Hugo Weaving<OPTION>Lambert 
  Wilson<OPTION>Anthony Wong</OPTION></SELECT>
<SCRIPT type=text/javascript>
var myfilter = new filterlist(document.myform.myselect);  //調(diào)用過濾的方法
</SCRIPT>
 
<P>過濾： <A title="Clear the filter" 
href="javascript:myfilter.reset()">重置</A> <A 
title="Show items starting with A" href="javascript:myfilter.set('^A')">A</A> <A 
title="Show items starting with B" href="javascript:myfilter.set('^B')">B</A> <A 
title="Show items starting with C" href="javascript:myfilter.set('^C')">C</A> <A 
title="Show items starting with D" href="javascript:myfilter.set('^D')">D</A> <A 
title="Show items starting with E" href="javascript:myfilter.set('^E')">E</A> <A 
title="Show items starting with F" href="javascript:myfilter.set('^F')">F</A> <A 
title="Show items starting with G" href="javascript:myfilter.set('^G')">G</A> <A 
title="Show items starting with H" href="javascript:myfilter.set('^H')">H</A> <A 
title="Show items starting with I" href="javascript:myfilter.set('^I')">I</A> <A 
title="Show items starting with J" href="javascript:myfilter.set('^J')">J</A> <A 
title="Show items starting with K" href="javascript:myfilter.set('^K')">K</A> <A 
title="Show items starting with L" href="javascript:myfilter.set('^L')">L</A> <A 
title="Show items starting with M" href="javascript:myfilter.set('^M')">M</A> <A 
title="Show items starting with N" href="javascript:myfilter.set('^N')">N</A> <A 
title="Show items starting with O" href="javascript:myfilter.set('^O')">O</A> <A 
title="Show items starting with P" href="javascript:myfilter.set('^P')">P</A> <A 
title="Show items starting with Q" href="javascript:myfilter.set('^Q')">Q</A> <A 
title="Show items starting with R" href="javascript:myfilter.set('^R')">R</A> <A 
title="Show items starting with S" href="javascript:myfilter.set('^S')">S</A> <A 
title="Show items starting with T" href="javascript:myfilter.set('^T')">T</A> <A 
title="Show items starting with U" href="javascript:myfilter.set('^U')">U</A> <A 
title="Show items starting with V" href="javascript:myfilter.set('^V')">V</A> <A 
title="Show items starting with W" href="javascript:myfilter.set('^W')">W</A> <A 
title="Show items starting with X" href="javascript:myfilter.set('^X')">X</A> <A 
title="Show items starting with Y" href="javascript:myfilter.set('^Y')">Y</A> <A 
title="Show items starting with Z" href="javascript:myfilter.set('^Z')">Z</A> 
</P></FORM></BODY></HTML>

【運(yùn)行效果】

Ajax效果的字符串過濾運(yùn)行效果

【難點(diǎn)剖析】

本例的重點(diǎn)是使用正則表達(dá)式實(shí)現(xiàn)字符的過濾，還實(shí)現(xiàn)了動態(tài)添加列表項(xiàng)的功能。代碼中使用“new”關(guān)鍵字創(chuàng)建了RegExp對象，其用來提供簡單的正則表達(dá)式支持功能。使用RegExp對象的“test”方法，可以對指定的字符串執(zhí)行一個(gè)正則表達(dá)式搜索，并返回一個(gè)布爾值指示是否找到匹配的模式。當(dāng)搜索到結(jié)果時(shí)就使用“new Option”動態(tài)創(chuàng)建一個(gè)列表項(xiàng)，同時(shí)添加到列表中。

【源碼下載】

為了JS代碼的準(zhǔn)確性，請點(diǎn)擊：Ajax效果的字符串過濾進(jìn)行本實(shí)例源碼下載

標(biāo)簽： Ajax效果字符串