156 lines
13 KiB
HTML
156 lines
13 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::to_wstring</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_string_basic_string_to_wstring 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::</span>to_wstring</h1>
|
|
<div id="bodyContent">
|
|
<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-string.html">string</a>‎ | <a href="cpp-string-basic_string.html">basic string</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-string.html"><string></a></code></div>
|
|
</td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">int</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(1)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">long</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(2)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">long</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(3)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">unsigned</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(4)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">unsigned</span> <span class="kw4">long</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(5)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">unsigned</span> <span class="kw4">long</span> <span class="kw4">long</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(6)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">float</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(7)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">double</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(8)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl t-since-cxx11">
|
|
<td>
|
|
<div><span class="mw-geshi cpp source-cpp"><a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> to_wstring<span class="br0">(</span> <span class="kw4">long</span> <span class="kw4">double</span> value <span class="br0">)</span><span class="sy4">;</span></span></div>
|
|
</td>
|
|
<td>(9)</td>
|
|
<td><span class="t-mark-rev t-since-cxx11">(C++11 起)</span></td>
|
|
</tr>
|
|
<tr class="t-dcl-sep">
|
|
<td></td>
|
|
<td></td>
|
|
<td></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<p>转换数值为 <span class="t-lc"><a href="cpp-string-basic_string.html">std::wstring</a></span> 。</p>
|
|
<div class="t-li1"><span class="t-li">1)</span> 转换有符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%d"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">2)</span> 转换有符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%ld"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">3)</span> 转换有符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%lld"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">4)</span> 转换无符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%u"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">5)</span> 转换无符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%lu"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">6)</span> 转换无符号十进制整数为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%llu"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">7,8)</span> 转换浮点值为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%f"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<div class="t-li1"><span class="t-li">9)</span> 转换浮点值为宽字符串，其内容与 <span class="t-c"><span class="mw-geshi cpp source-cpp"><a href="cpp-io-c-fwprintf.html"><span class="kw1860">std::<span class="me2">swprintf</span></span></a><span class="br0">(</span>buf, sz, L<span class="st0">"%Lf"</span>, value<span class="br0">)</span></span></span> 对于充分大的 <code>buf</code> 将会生成的内容相同。</div>
|
|
<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>value</td>
|
|
<td>-</td>
|
|
<td>要转换的数值</td>
|
|
</tr>
|
|
</table>
|
|
<h3><span class="mw-headline" id=".E8.BF.94.E5.9B.9E.E5.80.BC">返回值</span></h3>
|
|
<p>保有转换后值的宽字符串</p>
|
|
<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">异常</span></h3>
|
|
<p>可能从 <span class="t-lc"><a href="cpp-string-basic_string.html">std::wstring</a></span> 的构造函数抛出 <span class="t-lc"><a href="cpp-memory-new-bad_alloc.html">std::bad_alloc</a></span> 。</p>
|
|
<h3><span class="mw-headline" id=".E7.A4.BA.E4.BE.8B">示例</span></h3>
|
|
<div class="t-example">
|
|
<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 <string></span>
|
|
<span class="co2">#include <iostream></span>
|
|
|
|
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span> <span class="br0">{</span>
|
|
<span class="kw4">double</span> f <span class="sy1">=</span> <span class="nu16">23.43</span><span class="sy4">;</span>
|
|
<a href="cpp-string-basic_string.html"><span class="kw1232">std::<span class="me2">wstring</span></span></a> f_str <span class="sy1">=</span> std<span class="sy4">::</span><span class="me2">to_wstring</span><span class="br0">(</span>f<span class="br0">)</span><span class="sy4">;</span>
|
|
<a href="cpp-io-cout.html"><span class="kw1758">std::<span class="me2">wcout</span></span></a> <span class="sy1"><<</span> f_str<span class="sy4">;</span>
|
|
<span class="br0">}</span></pre></div>
|
|
</div>
|
|
<p>输出：</p>
|
|
<div dir="ltr" class="mw-geshi" style="text-align: left;">
|
|
<div class="text source-text">
|
|
<pre class="de1">23.430000</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 class="t-dsc">
|
|
<td>
|
|
<div class="t-dsc-member-div">
|
|
<div><a href="cpp-string-basic_string-to_string.html"><span class="t-lines"><span>to_string</span></span></a></div>
|
|
<div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div>
|
|
</div>
|
|
</td>
|
|
<td>转换整数或浮点值为 <code>string</code><br />
|
|
<span class="t-mark">(函数)</span></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<div class="visualClear"></div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html>
|