CStdioFile默认无法向文件中写入中文字符，如以下代码文件以CStdioFile向文本中写入中文，但是用notepad.exe查 看不到写入的中文

CStdioFile file;
file.Open(…);
file.WriteString(_T("abc你好"));//只能写入abc

解决办法：

使用setlocale语句设定区域

#include <locale>//头文件
CStdioFile file;
file.Open(…);
char* old_locale = _strdup( setlocale(LC_CTYPE,NULL) );
setlocale( LC_CTYPE, "chs" );//设定
file.WriteString(_T("abc你好"));//正常写入
setlocale( LC_CTYPE, old_locale );
free( old_locale );//还原区域设定

简化处理可以仅使用语句setlocale( LC_CTYPE, "chs" )。

setlocale函数说明:

函数原形为：char *setlocale( int category, const char *locale );
包含的头文件：<locale.h>
所支持的操作系统为:ANSI, Win 95, Win NT
对于简体中文可以使用如下设置：setlocale( LC_ALL, "chs" );

为什么一定要调用setlocale呢？

因为在C/C++语言标准中定义了其运行时的字符集环境为"C"，也就是ASCII字符集的一个子集，那么mbstowcs在工作时会将cstr中所包含 的字符串看作是ASCII编码的字符，而不认为是一个包含有chs编码的字符串，所以他会将每一个中文拆成2个ASCII编码进行转换，这样得到的结果就 是会形成4个wchar_t的字符组成的串，那么如何才能够让mbstowcs正常工作呢？在调用mbstowcs进行转换之间必须明确的告诉 mbstowcs目前cstr串中包含的是chs编码的字符串，通过setlocale( LC_ALL, "chs" )函数调用来完成，需要注意的是这个函数会改变整个应用程序的字符集编码方式，必须要通过重新调用setlocale( LC_ALL, "C" )函数来还原，这样就可以保证mbstowcs在转换时将cstr中的串看作是中文串，并且转换成为2个wchar_t字符，而不是4个。

本地化设置需要具备三个条件：
a. 语言代码 (Language Code)
b. 国家代码 (Country Code)
c. 编码(Encoding)
本地名字可以用下面这些部分来构造：
语言代码_国家代码.编码 比如（zh_CN.UTF-8, en_US等）

setlocale语言字符串参考

Primary language	Sublanguage	Language string
Chinese	Chinese	"chinese"
Chinese	Chinese (simplified)	"chinese-simplified" or "chs"
Chinese	Chinese (traditional)	"chinese-traditional" or "cht"
Czech	Czech	"csy" or "czech"
Danish	Danish	"dan" or "danish"
Dutch	Dutch (default)	"dutch" or "nld"
Dutch	Dutch (Belgian)	"belgian", "dutch-belgian", or "nlb"
English	English (default)	"english"
English	English (Australian)	"australian", "ena", or "english-aus"
English	English (Canadian)	"canadian", "enc", or "english-can"
English	English (New Zealand)	"english-nz" or "enz"
English	English (United Kingdom)	"eng", "english-uk", or "uk"
English	English (United States)	"american", "american english", "american-english", "english-american", "english-us", "english-usa", "enu", "us", or "usa"
Finnish	Finnish	"fin" or "finnish"
French	French (default)	"fra" or "french"
French	French (Belgian)	"frb" or "french-belgian"
French	French (Canadian)	"frc" or "french-canadian"
French	French (Swiss)	"french-swiss" or "frs"
German	German (default)	"deu" or "german"
German	German (Austrian)	"dea" or "german-austrian"
German	German (Swiss)	"des", "german-swiss", or "swiss"
Greek	Greek	"ell" or "greek"
Hungarian	Hungarian	"hun" or "hungarian"
Icelandic	Icelandic	"icelandic" or "isl"
Italian	Italian (default)	"ita" or "italian"
Italian	Italian (Swiss)	"italian-swiss" or "its"
Japanese	Japanese	"japanese" or "jpn"
Korean	Korean	"kor" or "korean"
Norwegian	Norwegian (default)	"norwegian"
Norwegian	Norwegian (Bokmal)	"nor" or "norwegian-bokmal"
Norwegian	Norwegian (Nynorsk)	"non" or "norwegian-nynorsk"
Polish	Polish	"plk" or "polish"
Portuguese	Portuguese (default)	"portuguese" or "ptg"
Portuguese	Portuguese (Brazilian)	"portuguese-brazil" or "ptb"
Russian	Russian (default)	"rus" or "russian"
Slovak	Slovak	"sky" or "slovak"
Spanish	Spanish (default)	"esp" or "spanish"
Spanish	Spanish (Mexican)	"esm" or "spanish-mexican"
Spanish	Spanish (Modern)	"esn" or "spanish-modern"
Swedish	Swedish	"sve" or "swedish"
Turkish	Turkish	"trk" or "turkish"

 
setlocale国家字符串参考

Country/Region	Country/Region string
Australia	"aus" or "australia"
Austria	"aut" or "austria"
Belgium	"bel" or "belgium"
Brazil	"bra" or "brazil"
Canada	"can" or "canada"
China	"china", "chn", "pr china", or "pr-china"
Czech Republic	"cze" or "czech"
Denmark	"dnk" or "denmark"
Finland	"fin" or "finland"
France	"fra" or "france"
Germany	"deu" or "germany"
Greece	"grc" or "greece"
Hong Kong SAR	"hkg", "hong kong", or "hong-kong"
Hungary	"hun" or "hungary"
Iceland	"iceland" or "isl"
Ireland	"irl" or "ireland"
Italy	"ita" or "italy"
Japan	"jpn" or "japan"
Korea	"kor" or "korea"
Mexico	"mex" or "mexico"
The Netherlands	"nld", "holland", or "netherlands"
New Zealand	"nzl", "new zealand", "new-zealand", or "nz"
Norway	"nor" or "norway"
Poland	"pol" or "poland"
Portugal	"prt" or "portugal"
Russia	"rus" or "russia"
Singapore	"sgp" or "singapore"
Slovakia	"svk" or "slovak"
Spain	"esp" or "spain"
Sweden	"swe" or "sweden"
Switzerland	"che" or "switzerland"
Taiwan	"twn" or "taiwan"
Turkey	"tur" or "turkey"
United Kingdom	"gbr", "britain", "england", "great britain", "uk", "united kingdom", or "united-kingdom"
United States	"usa", "america", "united states", "united-states", or "us"