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framework.functions.html
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<!DOCTYPE html>
<html dir="ltr" class="js desktop" lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<meta charset="utf-8">
<title>framework.functions</title>
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<div class="pageId"><span>zh_cn:api:framework.functions</span></div>
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<!-- TOC START -->
<div id="dw__toc">
<h3 class="toggle">Table of Contents</h3>
<div>
<ul class="toc">
<li class="level1"><div class="li"><a href="#frameworkfunctions">framework.functions</a></div>
<ul class="toc">
<li class="level2"><div class="li"><a href="#tonumber">tonumber</a></div></li>
<li class="level2"><div class="li"><a href="#toint">toint</a></div></li>
<li class="level2"><div class="li"><a href="#tobool">tobool</a></div></li>
<li class="level2"><div class="li"><a href="#totable">totable</a></div></li>
<li class="level2"><div class="li"><a href="#clone">clone</a></div></li>
<li class="level2"><div class="li"><a href="#class">class</a></div></li>
<li class="level2"><div class="li"><a href="#import">import</a></div></li>
<li class="level2"><div class="li"><a href="#handler">handler</a></div></li>
<li class="level2"><div class="li"><a href="#mathround">math.round</a></div></li>
<li class="level2"><div class="li"><a href="#ioexists">io.exists</a></div></li>
<li class="level2"><div class="li"><a href="#ioreadfile">io.readfile</a></div></li>
<li class="level2"><div class="li"><a href="#iowritefile">io.writefile</a></div></li>
<li class="level2"><div class="li"><a href="#iopathinfo">io.pathinfo</a></div></li>
<li class="level2"><div class="li"><a href="#iofilesize">io.filesize</a></div></li>
<li class="level2"><div class="li"><a href="#tablenums">table.nums</a></div></li>
<li class="level2"><div class="li"><a href="#tablekeys">table.keys</a></div></li>
<li class="level2"><div class="li"><a href="#tablevalues">table.values</a></div></li>
<li class="level2"><div class="li"><a href="#tablemerge">table.merge</a></div></li>
<li class="level2"><div class="li"><a href="#stringhtmlspecialchars">string.htmlspecialchars</a></div></li>
<li class="level2"><div class="li"><a href="#stringnl2br">string.nl2br</a></div></li>
<li class="level2"><div class="li"><a href="#stringtext2html">string.text2html</a></div></li>
<li class="level2"><div class="li"><a href="#stringsplit">string.split</a></div></li>
<li class="level2"><div class="li"><a href="#stringltrim">string.ltrim</a></div></li>
<li class="level2"><div class="li"><a href="#stringrtrim">string.rtrim</a></div></li>
<li class="level2"><div class="li"><a href="#stringtrim">string.trim</a></div></li>
<li class="level2"><div class="li"><a href="#stringucfirst">string.ucfirst</a></div></li>
<li class="level2"><div class="li"><a href="#stringurlencode">string.urlencode</a></div></li>
<li class="level2"><div class="li"><a href="#stringutf8len">string.utf8len</a></div></li>
<li class="level2"><div class="li"><a href="#stringformatnumberthousands">string.formatNumberThousands</a></div></li>
</ul></li>
</ul>
</div>
</div>
<!-- TOC END -->
<h1 class="sectionedit1" id="frameworkfunctions">framework.functions</h1>
<div class="level1">
<p>
补充了一些常用函数，并替换了少量内置函数。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit2" id="tonumber">tonumber</h2>
<div class="level2">
<p>
转换为数值，如果无法转换则返回 0。
</p>
<p>
tonumber() 原本是 Lua 内置函数，但内置版本在无法转换时会返回 nil，这样还是需要进行后续判断。quick 替换了内置版本。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> <span class="kw3">tonumber</span><span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit3" id="toint">toint</h2>
<div class="level2">
<p>
转换为整数，如果无法转换则返回 0。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> toint<span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit4" id="tobool">tobool</h2>
<div class="level2">
<p>
转换为布尔值。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> tobool<span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit5" id="totable">totable</h2>
<div class="level2">
<p>
转换为表格，如果传入的值不是表格，则返回一个空表格。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> totable<span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit6" id="clone">clone</h2>
<div class="level2">
<p>
深度克隆一个值。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> clone<span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="co1">-- 下面的代码，t2 是 t1 的引用，修改 t2 的属性时，t1 的内容也会发生变化</span>
<span class="kw1">local</span> t1 <span class="sy0">=</span> <span class="br0">{</span>a <span class="sy0">=</span> <span class="nu0">1</span><span class="sy0">,</span> b <span class="sy0">=</span> <span class="nu0">2</span><span class="br0">}</span>
<span class="kw1">local</span> t2 <span class="sy0">=</span> t1
t2<span class="sy0">.</span>b <span class="sy0">=</span> <span class="nu0">3</span> <span class="co1">-- t1 = {a = 1, b = 3} <-- t1.b 发生变化</span>
<span class="co1">-- clone() 返回 t1 的副本，修改 t2 不会影响 t1</span>
<span class="kw1">local</span> t1 <span class="sy0">=</span> <span class="br0">{</span>a <span class="sy0">=</span> <span class="nu0">1</span><span class="sy0">,</span> b <span class="sy0">=</span> <span class="nu0">2</span><span class="br0">}</span>
<span class="kw1">local</span> t2 <span class="sy0">=</span> clone<span class="br0">(</span>t1<span class="br0">)</span>
t2<span class="sy0">.</span>b <span class="sy0">=</span> <span class="nu0">3</span> <span class="co1">-- t1 = {a = 1, b = 2} <-- t1.b 不受影响</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit7" id="class">class</h2>
<div class="level2">
<p>
创建一个类。
</p>
<p>
格式：
</p>
<pre class="code lua">类 <span class="sy0">=</span> class<span class="br0">(</span>类名<span class="sy0">,</span> <span class="br0">[</span>父类<span class="br0">]</span><span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="co1">-- 定义名为 Shape 的基础类</span>
<span class="kw1">local</span> Shape <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"Shape"</span><span class="br0">)</span>
<span class="co1">-- ctor() 是类的构造函数，在调用 Shape.new() 创建 Shape 对象实例时会自动执行</span>
<span class="kw1">function</span> Shape<span class="sy0">:</span>ctor<span class="br0">(</span>shapeName<span class="br0">)</span>
self<span class="sy0">.</span>shapeName <span class="sy0">=</span> shapeName
printf<span class="br0">(</span><span class="st0">"Shape:ctor(%s)"</span><span class="sy0">,</span> self<span class="sy0">.</span>shapeName<span class="br0">)</span>
<span class="kw1">end</span>
<span class="co1">-- 为 Shape 定义个名为 draw() 的方法</span>
<span class="kw1">function</span> Shape<span class="sy0">:</span>draw<span class="br0">(</span><span class="br0">)</span>
printf<span class="br0">(</span><span class="st0">"draw %s"</span><span class="sy0">,</span> self<span class="sy0">.</span>shapeName<span class="br0">)</span>
<span class="kw1">end</span>
<span class="co1">--</span>
<span class="co1">-- Circle 是 Shape 的继承类</span>
<span class="kw1">local</span> Circle <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"Circle"</span><span class="sy0">,</span> Shape<span class="br0">)</span>
<span class="kw1">function</span> Circle<span class="sy0">:</span>ctor<span class="br0">(</span><span class="br0">)</span>
<span class="co1">-- 如果继承类覆盖了 ctor() 构造函数，那么必须手动调用父类构造函数</span>
<span class="co1">-- 类名.super 可以访问指定类的父类</span>
Circle<span class="sy0">.</span>super<span class="sy0">.</span>ctor<span class="br0">(</span>self<span class="sy0">,</span> <span class="st0">"circle"</span><span class="br0">)</span>
self<span class="sy0">.</span>radius <span class="sy0">=</span> <span class="nu0">100</span>
<span class="kw1">end</span>
<span class="kw1">function</span> Circle<span class="sy0">:</span>setRadius<span class="br0">(</span>radius<span class="br0">)</span>
self<span class="sy0">.</span>radius <span class="sy0">=</span> radius
<span class="kw1">end</span>
<span class="co1">-- 覆盖父类的同名方法</span>
<span class="kw1">function</span> Circle<span class="sy0">:</span>draw<span class="br0">(</span><span class="br0">)</span>
printf<span class="br0">(</span><span class="st0">"draw %s, raidus = %0.2f"</span><span class="sy0">,</span> self<span class="sy0">.</span>shapeName<span class="sy0">,</span> self<span class="sy0">.</span>raidus<span class="br0">)</span>
<span class="kw1">end</span>
<span class="co1">--</span>
<span class="kw1">local</span> Rectangle <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"Rectangle"</span><span class="sy0">,</span> Shape<span class="br0">)</span>
<span class="kw1">function</span> Rectangle<span class="sy0">:</span>ctor<span class="br0">(</span><span class="br0">)</span>
Rectangle<span class="sy0">.</span>super<span class="sy0">.</span>ctor<span class="br0">(</span>self<span class="sy0">,</span> <span class="st0">"rectangle"</span><span class="br0">)</span>
<span class="kw1">end</span>
<span class="co1">--</span>
<span class="kw1">local</span> circle <span class="sy0">=</span> Circle<span class="sy0">.</span>new<span class="br0">(</span><span class="br0">)</span> <span class="co1">-- 输出: Shape:ctor(circle)</span>
circle<span class="sy0">:</span>setRaidus<span class="br0">(</span><span class="nu0">200</span><span class="br0">)</span>
circle<span class="sy0">:</span>draw<span class="br0">(</span><span class="br0">)</span> <span class="co1">-- 输出: draw circle, radius = 200.00</span>
<span class="kw1">local</span> rectangle <span class="sy0">=</span> Rectangle<span class="sy0">.</span>new<span class="br0">(</span><span class="br0">)</span> <span class="co1">-- 输出: Shape:ctor(rectangle)</span>
rectangle<span class="sy0">:</span>draw<span class="br0">(</span><span class="br0">)</span> <span class="co1">-- 输出: draw rectangle</span></pre>
<p>
请参考：
<a href="framework.functions.class.html" class="wikilink1" title="zh_cn:api:framework.functions:class">class() 高级用法</a>
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit8" id="import">import</h2>
<div class="level2">
<p>
载入一个模块。
</p>
<p>
格式：
</p>
<pre class="code lua">import<span class="br0">(</span>模块名<span class="br0">)</span></pre>
<p>
import() 与 require() 功能相同，但具有一定程度的自动化特性。
</p>
<p>
假设我们有如下的目录结构：
</p>
<ul>
<li class="level1"><div class="li">app/</div>
<ul>
<li class="level2"><div class="li">classes/</div>
<ul>
<li class="level3"><div class="li">MyClass.lua</div>
</li>
<li class="level3"><div class="li">MyClassBase.lua</div>
</li>
<li class="level3"><div class="li">data/</div>
<ul>
<li class="level4"><div class="li">Data1.lua</div>
</li>
<li class="level4"><div class="li">Data2.lua</div>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
<p>
MyClass 中需要载入 MyClassBase 和 MyClassData。如果用 require()，MyClass 内的代码如下：
</p>
<pre class="code lua"><span class="kw1">local</span> MyClassBase <span class="sy0">=</span> <span class="kw3">require</span><span class="br0">(</span><span class="st0">"app.classes.MyClassBase"</span><span class="br0">)</span>
<span class="kw1">local</span> MyClass <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"MyClass"</span><span class="sy0">,</span> MyClassBase<span class="br0">)</span>
<span class="kw1">local</span> Data1 <span class="sy0">=</span> <span class="kw3">require</span><span class="br0">(</span><span class="st0">"app.classes.data.Data1"</span><span class="br0">)</span>
<span class="kw1">local</span> Data2 <span class="sy0">=</span> <span class="kw3">require</span><span class="br0">(</span><span class="st0">"app.classes.data.Data2"</span><span class="br0">)</span></pre>
<p>
假如我们将 MyClass 及其相关文件换一个目录存放，那么就必须修改 MyClass 中的 require() 命令，否则将找不到模块文件。
</p>
<p>
而使用 import()，我们只需要如下写：
</p>
<pre class="code lua"><span class="kw1">local</span> MyClassBase <span class="sy0">=</span> import<span class="br0">(</span><span class="st0">".MyClassBase"</span><span class="br0">)</span>
<span class="kw1">local</span> MyClass <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"MyClass"</span><span class="sy0">,</span> MyClassBase<span class="br0">)</span>
<span class="kw1">local</span> Data1 <span class="sy0">=</span> import<span class="br0">(</span><span class="st0">".data.Data1"</span><span class="br0">)</span>
<span class="kw1">local</span> Data2 <span class="sy0">=</span> import<span class="br0">(</span><span class="st0">".data.Data2"</span><span class="br0">)</span></pre>
<p>
当在模块名前面有一个“.”时，import() 会从当前模块所在目录中查找其他模块。因此 MyClass 及其相关文件不管存放到什么目录里，我们都不再需要修改 MyClass 中的 import() 命令。这在开发一些重复使用的功能组件时，会非常方便。
</p>
<p>
我们可以在模块名前添加多个“.”，这样 import() 会从更上层的目录开始查找模块。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit9" id="handler">handler</h2>
<div class="level2">
<p>
将 Lua 对象及其方法包装为一个匿名函数。
</p>
<p>
格式：
</p>
<pre class="code lua">函数 <span class="sy0">=</span> handler<span class="br0">(</span>对象<span class="sy0">,</span> 对象<span class="sy0">.</span>方法<span class="br0">)</span></pre>
<p>
在 quick-cocos2d-x 中，许多功能需要传入一个 Lua 函数做参数，然后在特定事件发生时就会调用传入的函数。例如触摸事件、帧事件等等。
</p>
<pre class="code lua"><span class="kw1">local</span> MyScene <span class="sy0">=</span> class<span class="br0">(</span><span class="st0">"MyScene"</span><span class="sy0">,</span> <span class="kw1">function</span><span class="br0">(</span><span class="br0">)</span>
<span class="kw1">return</span> display<span class="sy0">.</span>newScene<span class="br0">(</span><span class="st0">"MyScene"</span><span class="br0">)</span>
<span class="kw1">end</span><span class="br0">)</span>
<span class="kw1">function</span> MyScene<span class="sy0">:</span>ctor<span class="br0">(</span><span class="br0">)</span>
self<span class="sy0">.</span>frameTimeCount <span class="sy0">=</span> <span class="nu0">0</span>
<span class="co1">-- 注册帧事件</span>
self<span class="sy0">:</span>scheduleUpdate<span class="br0">(</span>self<span class="sy0">.</span>onEnterFrame<span class="br0">)</span>
<span class="kw1">end</span>
<span class="kw1">function</span> MyScene<span class="sy0">:</span>onEnterFrame<span class="br0">(</span>dt<span class="br0">)</span>
self<span class="sy0">.</span>frameTimeCount <span class="sy0">=</span> self<span class="sy0">.</span>frameTimeCount <span class="sy0">+</span> dt
<span class="kw1">end</span></pre>
<p>
上述代码执行时将出错，报告“Invalid self”，这就是因为 C++ 无法识别 Lua 对象方法。因此在调用我们传入的 self.onEnterFrame 方法时没有提供正确的参数。
</p>
<p>
要让上述的代码正常工作，就需要使用 handler() 进行一下包装：
</p>
<pre class="code lua"><span class="kw1">function</span> MyScene<span class="sy0">:</span>ctor<span class="br0">(</span><span class="br0">)</span>
self<span class="sy0">.</span>frameTimeCount <span class="sy0">=</span> <span class="nu0">0</span>
<span class="co1">-- 注册帧事件</span>
self<span class="sy0">:</span>scheduleUpdate<span class="br0">(</span>handler<span class="br0">(</span>self<span class="sy0">,</span> self<span class="sy0">.</span>onEnterFrame<span class="br0">)</span><span class="br0">)</span>
<span class="kw1">end</span></pre>
<p>
实际上，除了 C++ 回调 Lua 函数之外，在其他所有需要回调的地方都可以使用 handler()。
</p>
<hr />
</div>
<h2 class="sectionedit10" id="mathround">math.round</h2>
<div class="level2">
<p>
对一个数值四舍五入，如果传入的参数不是数值，则返回 0。
</p>
<p>
格式：
</p>
<pre class="code lua">value <span class="sy0">=</span> <span class="kw3">math</span><span class="sy0">.</span>round<span class="br0">(</span>值<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit11" id="ioexists">io.exists</h2>
<div class="level2">
<p>
测试文件是否存在，如果存在返回 true。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">io</span><span class="sy0">.</span>exists<span class="br0">(</span>路径<span class="br0">)</span></pre>
<p>
可以使用 CCFileUtils:fullPathForFilename() 函数查找特定文件的完整路径，例如：
</p>
<pre class="code lua"><span class="kw1">local</span> path <span class="sy0">=</span> CCFileUtils<span class="sy0">:</span>sharedFileUtils<span class="br0">(</span><span class="br0">)</span><span class="sy0">:</span>fullPathForFilename<span class="br0">(</span><span class="st0">"gamedata.txt"</span><span class="br0">)</span>
<span class="kw1">if</span> <span class="kw3">io</span><span class="sy0">.</span>exists<span class="br0">(</span>path<span class="br0">)</span> <span class="kw1">then</span>
<span class="sy0">....</span>
<span class="kw1">end</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit12" id="ioreadfile">io.readfile</h2>
<div class="level2">
<p>
读取文件，并返回文件内容。
</p>
<p>
格式：
</p>
<pre class="code lua">contents <span class="sy0">=</span> <span class="kw3">io</span><span class="sy0">.</span>readfile<span class="br0">(</span>路径<span class="br0">)</span></pre>
<p>
io.readfile() 会一次性读取整个文件的内容，并返回一个字符串，因此该函数不适宜读取太大的文件。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit13" id="iowritefile">io.writefile</h2>
<div class="level2">
<p>
将内容写入文件，成功返回 true。
</p>
<p>
格式：
</p>
<pre class="code lua"><span class="kw3">io</span><span class="sy0">.</span>writefile<span class="br0">(</span>路径<span class="sy0">,</span> 内容<span class="sy0">,</span> 写入模式<span class="br0">)</span></pre>
<p>
“写入模式”参数决定 io.writefile() 如何写入内容，可用的值如下：
</p>
<ul>
<li class="level1"><div class="li">“w+”: 覆盖文件已有内容，如果文件不存在则创建新文件</div>
</li>
<li class="level1"><div class="li">“a+”: 追加内容到文件尾部，如果文件不存在则创建文件</div>
</li>
</ul>
<p>
此外，还可以在“写入模式”参数最后追加字符“b”，表示以二进制方式写入数据，这样在某些平台上可以避免内容写入不完整。
</p>
<p>
io.writefile() 默认的“写入参数”是“w+b”。
</p>
<p>
<strong>Android 特别提示：</strong>在 Android 平台上，文件只能写入存储卡所在路径，assets 和 data 等目录都是无法写入的。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit14" id="iopathinfo">io.pathinfo</h2>
<div class="level2">
<p>
拆分一个路径字符串，返回组成路径的各个部分。
</p>
<p>
格式：
</p>
<pre class="code lua">parts <span class="sy0">=</span> <span class="kw3">io</span><span class="sy0">.</span>pathinfo<span class="br0">(</span>路径<span class="br0">)</span></pre>
<p>
使用示例：
</p>
<pre class="code lua"><span class="kw1">local</span> pathinfo <span class="sy0">=</span> <span class="kw3">io</span><span class="sy0">.</span>pathinfo<span class="br0">(</span><span class="st0">"/var/app/test/abc.png"</span><span class="br0">)</span>
<span class="co1">-- pathinfo.dirname = "/var/app/test/"</span>
<span class="co1">-- pathinfo.filename = "abc.png"</span>
<span class="co1">-- pathinfo.basename = "abc"</span>
<span class="co1">-- pathinfo.extname = ".png"</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit15" id="iofilesize">io.filesize</h2>
<div class="level2">
<p>
返回指定文件的大小，如果失败返回 false。
</p>
<p>
格式：
</p>
<pre class="code lua">size <span class="sy0">=</span> <span class="kw3">io</span><span class="sy0">.</span>filesize<span class="br0">(</span>路径<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit16" id="tablenums">table.nums</h2>
<div class="level2">
<p>
计算表格包含的字段数量。
</p>
<p>
格式：
</p>
<pre class="code lua">count <span class="sy0">=</span> <span class="kw3">table</span><span class="sy0">.</span>nums<span class="br0">(</span>表格对象<span class="br0">)</span></pre>
<p>
Lua 的“#”操作可以取得表格的长度，但仅限从 1 开始连续数字为索引的表格。table.nums() 可以计算任何表格的长度。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit17" id="tablekeys">table.keys</h2>
<div class="level2">
<p>
返回指定表格中的所有键。
</p>
<p>
格式：
</p>
<pre class="code lua">keys <span class="sy0">=</span> <span class="kw3">table</span><span class="sy0">.</span>keys<span class="br0">(</span>表格对象<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> t <span class="sy0">=</span> <span class="br0">{</span>a <span class="sy0">=</span> <span class="nu0">1</span><span class="sy0">,</span> b <span class="sy0">=</span> <span class="nu0">2</span><span class="sy0">,</span> c <span class="sy0">=</span> <span class="nu0">3</span><span class="br0">}</span>
<span class="kw1">local</span> keys <span class="sy0">=</span> <span class="kw3">table</span><span class="sy0">.</span>keys<span class="br0">(</span>t<span class="br0">)</span>
<span class="co1">-- keys = {"a", "b", "c"}</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit18" id="tablevalues">table.values</h2>
<div class="level2">
<p>
返回指定表格中的所有值。
</p>
<p>
格式：
</p>
<pre class="code lua">values <span class="sy0">=</span> <span class="kw3">table</span><span class="sy0">.</span>values<span class="br0">(</span>表格对象<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> t <span class="sy0">=</span> <span class="br0">{</span>a <span class="sy0">=</span> <span class="st0">"1"</span><span class="sy0">,</span> b <span class="sy0">=</span> <span class="st0">"2"</span><span class="sy0">,</span> c <span class="sy0">=</span> <span class="st0">"3"</span><span class="br0">}</span>
<span class="kw1">local</span> values <span class="sy0">=</span> <span class="kw3">table</span><span class="sy0">.</span>values<span class="br0">(</span>t<span class="br0">)</span>
<span class="co1">-- values = {1, 2, 3}</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit19" id="tablemerge">table.merge</h2>
<div class="level2">
<p>
合并两个表格。
</p>
<p>
格式：
</p>
<pre class="code lua"><span class="kw3">table</span><span class="sy0">.</span>merge<span class="br0">(</span>目标表格对象<span class="sy0">,</span> 来源表格对象<span class="br0">)</span></pre>
<p>
将来源表格中所有键及其值复制到目标表格对象中，如果存在同名键，则覆盖其值。
</p>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> dest <span class="sy0">=</span> <span class="br0">{</span>a <span class="sy0">=</span> <span class="nu0">1</span><span class="sy0">,</span> b <span class="sy0">=</span> <span class="nu0">2</span><span class="br0">}</span>
<span class="kw1">local</span> src <span class="sy0">=</span> <span class="br0">{</span>c <span class="sy0">=</span> <span class="nu0">3</span><span class="sy0">,</span> d <span class="sy0">=</span> <span class="nu0">4</span><span class="br0">}</span>
<span class="kw3">table</span><span class="sy0">.</span>merge<span class="br0">(</span>dest<span class="sy0">,</span> src<span class="br0">)</span>
<span class="co1">-- dest = {a = 1, b = 2, c = 3, d = 4}</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit20" id="stringhtmlspecialchars">string.htmlspecialchars</h2>
<div class="level2">
<p>
转换特殊的字符为 <abbr title="HyperText Markup Language">HTML</abbr> 编码。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>htmlspecialchars<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
下列字符会被转换：
</p>
<ul>
<li class="level1"><div class="li">'&' (ampersand) 转换为 '&amp;'</div>
</li>
<li class="level1"><div class="li">'”' (double quote) 转换为 '&quot;'</div>
</li>
<li class="level1"><div class="li">”'” (single quote) 转换为 '&#039;'</div>
</li>
<li class="level1"><div class="li">'<' (less than) 转换为 '&lt;'</div>
</li>
<li class="level1"><div class="li">'>' (greater than) 转换为 '&gt;'</div>
</li>
</ul>
<p>
~~
</p>
</div>
<h2 class="sectionedit21" id="stringnl2br">string.nl2br</h2>
<div class="level2">
<p>
将字符串中的换行符转换为 <abbr title="HyperText Markup Language">HTML</abbr> 换行标记。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>nl2br<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> text <span class="sy0">=</span> <span class="st0">"Hello<span class="es1">\n</span>World."</span>
<span class="kw1">local</span> result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>nl2br<span class="br0">(</span>text<span class="br0">)</span>
<span class="co1">-- result = "Hello<br />World."</span></pre>
<p>
将 string.nl2br() 和 string.htmlspecialchars() 结合使用，可以对字符串进行转换，确保转换结果符合 <abbr title="HyperText Markup Language">HTML</abbr> 要求，并且没有安全问题。
</p>
<pre class="code lua"><span class="kw1">local</span> text <span class="sy0">=</span> <span class="st0">"---> Hello<span class="es1">\n</span>World <---"</span>
<span class="kw1">local</span> result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>nl2br<span class="br0">(</span><span class="kw3">string</span><span class="sy0">.</span>htmlspecialchars<span class="br0">(</span>text<span class="br0">)</span><span class="br0">)</span>
<span class="co1">-- result = "---&gt; Hello<br /> &lt;---"</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit22" id="stringtext2html">string.text2html</h2>
<div class="level2">
<p>
对字符串进行格式化，确保其中的特殊字符都转换为 <abbr title="HyperText Markup Language">HTML</abbr> 标记。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>text2html<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
string.text2html() 除了转换特殊字符和换行符，还会将制表符“\t”替换为空格，再将空格替换为“&nbsp;”。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit23" id="stringsplit">string.split</h2>
<div class="level2">
<p>
分割字符串。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>split<span class="br0">(</span>要分割的字符串<span class="sy0">,</span> 分隔符<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>split<span class="br0">(</span><span class="st0">"1,2,3"</span><span class="sy0">,</span> <span class="st0">","</span><span class="br0">)</span>
<span class="co1">-- result = {"1", "2", "3"}</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit24" id="stringltrim">string.ltrim</h2>
<div class="level2">
<p>
删除字符串前部的空白字符。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>ltrim<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
空白字符包括：空格、制表符“\t”、换行符“\n”和“\r”。
</p>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>ltrim<span class="br0">(</span><span class="st0">" <span class="es1">\n</span><span class="es1">\t</span>Hello"</span><span class="br0">)</span>
<span class="co1">-- result = "Hello"</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit25" id="stringrtrim">string.rtrim</h2>
<div class="level2">
<p>
删除字符串尾部的空白字符。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>rtrim<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit26" id="stringtrim">string.trim</h2>
<div class="level2">
<p>
删除字符串两端的空白字符。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>trim<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit27" id="stringucfirst">string.ucfirst</h2>
<div class="level2">
<p>
返回首字母大写的字符串。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>ucfirst<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
~~
</p>
</div>
<h2 class="sectionedit28" id="stringurlencode">string.urlencode</h2>
<div class="level2">
<p>
生成符合 <abbr title="Uniform Resource Locator">URL</abbr> 规范的字符串。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>urlencode<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
为了通过 <abbr title="Uniform Resource Locator">URL</abbr> 传递数据，字符串中所有的非字母和数字都会被替换为“%编码”格式，空格会被替换为“+”。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit29" id="stringutf8len">string.utf8len</h2>
<div class="level2">
<p>
计算一个 UTF8 字符串包含的字符数量。
</p>
<p>
格式：
</p>
<pre class="code lua">count <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>utf8len<span class="br0">(</span>字符串<span class="br0">)</span></pre>
<p>
当一个 UTF8 字符串中包含中文时，string.len() 返回的结果是字符串的字节长度。string.utf8len() 会确保始终返回字符串中包含的字符数量。
</p>
<p>
~~
</p>
</div>
<h2 class="sectionedit30" id="stringformatnumberthousands">string.formatNumberThousands</h2>
<div class="level2">
<p>
将数字格式化为千分位格式。
</p>
<p>
格式：
</p>
<pre class="code lua">result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>formatNumberThousands<span class="br0">(</span>数值<span class="br0">)</span></pre>
<p>
用法示例：
</p>
<pre class="code lua"><span class="kw1">local</span> result <span class="sy0">=</span> <span class="kw3">string</span><span class="sy0">.</span>formatNumberThousands<span class="br0">(</span><span class="nu0">12345</span><span class="br0">)</span>
<span class="co1">-- result = "12,345"</span></pre>
</div>
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<div class="docInfo">zh_cn/api/framework.functions.txt · Last modified: 2013/08/20 06:42 by Yu Lei Liao</div>
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