113 lines
10 KiB
HTML
113 lines
10 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="zh" dir="ltr" class="client-nojs" xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh">
|
|
<head><meta http-equiv="x-ua-compatible" content="ie=edge">
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<title>std::messages<CharT>::open, std::messages<CharT>::do_open</title>
|
|
<link rel="stylesheet" href="ext.css" />
|
|
<link rel="stylesheet" href="site_modules.css" />
|
|
</head>
|
|
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_locale_messages_open skin-cppreference2 action-view cpp-navbar">
|
|
<div id="cpp-content-base">
|
|
<div id="content"><a id="top"></a>
|
|
<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::messages<CharT>::</span>open, <span style="font-size:0.7em; line-height:130%">std::messages<CharT>::</span>do_open</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-locale.html">locale</a>‎ | <a href="cpp-locale-messages.html">messages</a></span></div>
|
|
<div id="mw-content-text" lang="zh" dir="ltr" class="mw-content-ltr" xml:lang="zh">
|
|
<table class="t-dcl-begin">
|
|
<tbody>
|
|
<tr class="t-dsc-header">
|
|
<td>
|
|
<div>定义于头文件 <code><a href="cpp-header-locale.html"><locale></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">public</span><span class="sy4">:</span><br />
|
|
catalog open<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-string-basic_string.html"><span class="kw1228">std::<span class="me2">basic_string</span></span></a><span class="sy1"><</span><span class="kw4">char</span><span class="sy1">></span><span class="sy3">&</span> name, <span class="kw4">const</span> <a href="cpp-locale-locale.html"><span class="kw1894">std::<span class="me2">locale</span></span></a><span class="sy3">&</span> loc <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(1)</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><span class="kw1">protected</span><span class="sy4">:</span><br />
|
|
<span class="kw1">virtual</span> catalog do_open<span class="br0">(</span> <span class="kw4">const</span> <a href="cpp-string-basic_string.html"><span class="kw1228">std::<span class="me2">basic_string</span></span></a><span class="sy1"><</span><span class="kw4">char</span><span class="sy1">></span><span class="sy3">&</span> name, <span class="kw4">const</span> <a href="cpp-locale-locale.html"><span class="kw1894">std::<span class="me2">locale</span></span></a><span class="sy3">&</span> loc <span class="br0">)</span> <span class="kw4">const</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(2)</td>
|
|
<td class="t-dcl-nopad"></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>1) 公开成员函数，调用最终导出类的受保护虚成员函数 <code>do_open</code> 。</p>
|
|
<p>2) 获得 <code>catalog</code> 类型（继承自 <span class="t-lc"><a href="cpp-locale-messages_base.html">std::messages_base</a></span> ）值，能将它传递给 <span class="t-lc"><a href="cpp-locale-messages-get.html">get()</a></span> 以从 <code>name</code> 所指名的消息目录取得消息。此值可使用直至传递给 <span class="t-lc"><a href="cpp-locale-messages-close.html">close()</a></span> 为止。</p>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E6.95.B0">参数</span></h3>
|
|
<table class="t-par-begin">
|
|
<tr class="t-par">
|
|
<td>name</td>
|
|
<td>-</td>
|
|
<td>要打开的消息目录名称</td>
|
|
</tr>
|
|
<tr class="t-par">
|
|
<td>loc</td>
|
|
<td>-</td>
|
|
<td>提供可能为从目录读取消息所要求的额外平面，例如用以进行宽/多字节转换的 <span class="t-lc"><a href="cpp-locale-codecvt.html">std::codecvt</a></span> 的 locale 对象</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>能传递给 <span class="t-lc"><a href="cpp-locale-messages-get.html">get()</a></span> 和 <span class="t-lc"><a href="cpp-locale-messages-close.html">close()</a></span> 的非负 <code>catalog</code> 类型值。若无法打开目录则返回负值。</p>
|
|
<h3><span class="mw-headline" id=".E6.B3.A8.E6.84.8F">注意</span></h3>
|
|
<p>POSIX 系统上，此函数调用通常翻译为调用 <code><a rel="nofollow" class="external text" href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/catopen.html">catopen()</a></code> 。 GNU libstdc++ 中，它调用 <code><a rel="nofollow" class="external text" href="http://gcc.gnu.org/onlinedocs/libstdc++/manual/facets.html">textdomain</a></code> 。</p>
|
|
<p>实际目录位置是实现定义的：例如对于德文本地环境中的目录 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="st0">"sed"</span></span></span> （以 Unix 工具 <code>'sed'</code> 安装的消息目录），此函数调用所打开的文件可能为 <code>/usr/lib/nls/msg/de_DE/sed.cat</code>, <code>/usr/lib/locale/de_DE/LC_MESSAGES/sed.cat</code> 或 <code>/usr/share/locale/de/LC_MESSAGES/sed.mo</code> 。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<div class="t-example">
|
|
<p>下列代码演示消息取得：典型的 GNU/Linux 上，它从 <code>/usr/share/locale/de/LC_MESSAGES/sed.mo</code> 读取</p>
|
|
<div class="t-example-live-link"></div>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="cpp source-cpp">
|
|
<pre class="de1"><span class="co2">#include <iostream></span>
|
|
<span class="co2">#include <locale></span>
|
|
|
|
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
|
|
<span class="br0">{</span>
|
|
<a href="cpp-locale-locale.html"><span class="kw1894">std::<span class="me2">locale</span></span></a> loc<span class="br0">(</span><span class="st0">"de_DE.utf8"</span><span class="br0">)</span><span class="sy4">;</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a>.<span class="me1">imbue</span><span class="br0">(</span>loc<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">auto</span><span class="sy3">&</span> facet <span class="sy1">=</span> <a href="cpp-locale-use_facet.html"><span class="kw1897">std::<span class="me2">use_facet</span></span></a><span class="sy1"><</span><a href="cpp-locale-messages.html"><span class="kw1946">std::<span class="me2">messages</span></span></a><span class="sy1"><</span><span class="kw4">char</span><span class="sy1">>></span><span class="br0">(</span>loc<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw4">auto</span> cat <span class="sy1">=</span> facet.<span class="me1">open</span><span class="br0">(</span><span class="st0">"sed"</span>, loc<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="kw1">if</span><span class="br0">(</span>cat <span class="sy1"><</span> <span class="nu0">0</span> <span class="br0">)</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"Could not open german <span class="es1">\"</span>sed<span class="es1">\"</span> message catalog<span class="es1">\n</span>"</span><span class="sy4">;</span>
|
|
<span class="kw1">else</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> <span class="st0">"<span class="es1">\"</span>No match<span class="es1">\"</span> in German: "</span>
|
|
<span class="sy1"><<</span> facet.<span class="me1">get</span><span class="br0">(</span>cat, <span class="nu0">0</span>, <span class="nu0">0</span>, <span class="st0">"No match"</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span>
|
|
<span class="sy1"><<</span> <span class="st0">"<span class="es1">\"</span>Memory exhausted<span class="es1">\"</span> in German: "</span>
|
|
<span class="sy1"><<</span> facet.<span class="me1">get</span><span class="br0">(</span>cat, <span class="nu0">0</span>, <span class="nu0">0</span>, <span class="st0">"Memory exhausted"</span><span class="br0">)</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
|
|
facet.<span class="me1">close</span><span class="br0">(</span>cat<span class="br0">)</span><span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>可能的输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">"No match" in German: Keine Übereinstimmung
|
|
"Memory exhausted" in German: Speicher erschöpft</pre></div>
|
|
</div>
|
|
</div>
|
|
<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
|
|
<table class="t-dsc-begin">
|
|
<tr>
|
|
<td></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|