mbstowcs函数 [转载]

来源：互联网发布：windows桌面更新了很久编辑：程序博客网时间：2024/04/30 11:53

原文地址： http://blog.bitfly.cn/post/mbstowcs-func/

mbstowcs函数可以用了将multi-byte字符串转换为wide char字符串，是ISO/ANSI C标准函数。但是multi-byte受LC_CTYPE locale的变量的影响，需要设定为UTF-8才行。但是Windows上用setlocale没法设定为UTF-8，因此只能使用MultiByteToWideChar。

二者除了参数不同外，返回的size也不同(差一个结尾''的大小)。mbstowcs返回的长度不包含结尾''，MultiByteToWideChar则包含（准确的讲，是"MultiByteToWideChar does notnull-terminate an output string if the input string length is explicitlyspecified without a terminating null character. To null-terminate an outputstring for this function, the application should pass in -1 or explicitly countthe terminating null character for the input string."）。

完整代码:

#include  // for MultiByteToWideChar, WideCharToMultiByte#else#include  // for mbstocws, cwstombs#endifwchar_t* mb2wc(const char* mbstr){wchar_t* wcstr = NULL;// Get the size of wchar_t after converted#ifdef WIN32int size = MultiByteToWideChar(CP_UTF8, 0, mbstr, -1, NULL, 0);#elsesize_t size = mbstowcs(NULL, mbstr, 0);#endifwcstr = new wchar_t[size+1];if (wcstr){memset(wcstr, 0, size * sizeof(wchar_t));#ifdef WIN32int ret = MultiByteToWideChar(CP_UTF8, 0, mbstr, -1, wcstr, size);if (ret == 0) // MultiByteToWideChar returns 0 if it does not succeed.#elsesize_t ret = mbstowcs(wcstr, mbstr, size+1);if (ret == -1)#endif{delete[] wcstr;wcstr = NULL;}}return wcstr;}char* wc2mb(const wchar_t* wcstr){char* mbstr = NULL;// Get the size of char after converted#ifdef WIN32int size = WideCharToMultiByte(CP_UTF8, 0, wcstr, -1, NULL, 0, NULL, NULL);#elsesize_t size = wcstombs(NULL, wcstr, 0);#endifmbstr = new char[size+1];if (mbstr){memset(mbstr, 0, size * sizeof(char));#ifdef WIN32int ret = WideCharToMultiByte(CP_UTF8, 0, wcstr, -1, mbstr, size, NULL, NULL);if (ret == 0) // MultiByteToWideChar returns 0 if it does not succeed.#elsesize_t ret = wcstombs(mbstr, wcstr, size+1);if (ret == -1)#endif{delete[] mbstr;mbstr = NULL;}}return mbstr;}