用select2实现可搜索下拉框：开发难题与解决之道

<p[]用实现可搜索的下拉框</p>

开发时经常遇到选择项极多的下拉列表，挑选时相当不便，今日也碰上类似状况，遍寻网络资料与插件，最终找到一款操作简便的输入式下拉组件，这就是本文要介绍的对象

话不多说直接上代码

<p style='margin-bottom:15px;color:#555555;font-size:15px;line-height:200%;text-indent:2em;'> <pre><code class="prism language-html"><span class="token comment"></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>link</span> <span class="token attr-name">href</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>这个网址指向一个资源文件，包含了名为select2的库的样式表，版本是4.0.8，这个资源文件是一个CSS文件，用于定制下拉选择框的外观和功能，可以通过网络链接获取并使用<span class="token punctuation">"</span></span> <span class="token attr-name">rel</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>stylesheet<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token comment"></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>这个网址指向百度提供的jQuery库文件，版本是2.0.0，文件类型为压缩后的JavaScript代码，文件名包含了版本号后缀min，表明它是一个精简压缩版的库文件。<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment"></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>这个网址指向一个资源文件，它包含了select2的版本4.0.8的JavaScript代码，用户可以通过这个链接获取并使用该库。<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> </code></pre></p>

这段代码是核心所在，当我们加载了css和js之后，就能轻松地运用这个插件了，这里要特别留意的是，在加载js文件时，必须先加载普通版本，再加载带.min后缀的版本，否则会出现错误提示，这是由于该插件是依托某个框架进行封装的。

<p style='margin-bottom:15px;color:#555555;font-size:15px;line-height:200%;text-indent:2em;'> <pre><code class="prism language-javascript"><span class="token operator"><</span>script<span class="token operator">></span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#my-select"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">select2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> <span class="token operator"><</span><span class="token operator">/</span>script<span class="token operator">></span> </code></pre></p>

在页面部署时，仅需给目标搜索下拉框的标签元素赋予一个id标识，随后在脚本代码里完成该元素的初始化配置即可。

如下是完整代码

<p style='margin-bottom:15px;color:#555555;font-size:15px;line-height:200%;text-indent:2em;'> <pre><code class="prism language-html"><span class="token tag"><span class="token tag"><span class="token punctuation"><</span>html</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>title</span><span class="token punctuation">></span></span>select2<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>title</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>link</span> <span class="token attr-name">href</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.8/css/select2.min.css<span class="token punctuation">"</span></span> <span class="token attr-name">rel</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>stylesheet<span class="token punctuation">"</span></span> <span class="token punctuation">/></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>style</span><span class="token punctuation">></span></span><span class="token style language-css"> <span class="token selector">body</span> <span class="token punctuation">{</span>

<span class="token property">display</span><span class="token punctuation">:</span> flex<span class="token punctuation">;</span> <span class="token property">align-items</span><span class="token punctuation">:</span> center<span class="token punctuation">;</span> <span class="token property">justify-content</span><span class="token punctuation">:</span> center<span class="token punctuation">;</span> <span class="token punctuation">}</span> <span class="token selector">#my-select</span> <span class="token punctuation">{</span> <span class="token property">width</span><span class="token punctuation">:</span>190px<span class="token punctuation">;</span> <span class="token punctuation">}</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>style</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>head</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>body</span><span class="token punctuation">></span></span> 请选择省份： <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>select</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>my-select<span class="token punctuation">"</span></span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>option</span><span class="token punctuation">></span></span>请选择<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>option</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>option</span><span class="token punctuation">></span></span>陕西省<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>option</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>option</span><span class="token punctuation">></span></span>云南省<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>option</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>option</span><span class="token punctuation">></span></span>甘肃省<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>option</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>option</span><span class="token punctuation">></span></span>浙江省<span class="token tag"><span class="token tag"><span class="token punctuation"></</span>option</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>select</span><span class="token punctuation">></span></span> <span class="token comment"></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>http://libs.baidu.com/jquery/2.0.0/jquery.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token comment"></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span> <span class="token attr-name">src</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.8/js/select2.min.js<span class="token punctuation">"</span></span><span class="token punctuation">></span></span><span class="token script language-javascript"></span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"><</span>script</span><span class="token punctuation">></span></span><span class="token script language-javascript"> <span class="token function">$</span><span class="token punctuation">(</span><span class="token keyword">function</span> <span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span> <span class="token function">$</span><span class="token punctuation">(</span><span class="token string">"#my-select"</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">select2</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token punctuation">}</span><span class="token punctuation">)</span> </span><span class="token tag"><span class="token tag"><span class="token punctuation"></</span>script</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>body</span><span class="token punctuation">></span></span> <span class="token tag"><span class="token tag"><span class="token punctuation"></</span>html</span><span class="token punctuation">></span></span> </code></pre></p>

如有什么错误之处，请各位看官多多指出，共同进步！

# 的是  # 就能  # 是一个  # 这是  # 这段  # 加载  # 它是  # 可以通过  # 这就是  # 之处  # 陕西省  # 甘肃省  # 下拉框  # 请选择  # 包含了  # 云南省  # 用select2实现可搜索下拉框  # 开发难题与解决之道  # 如有  # 浙江省  # 当我们  # 请各位 

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