用标准C++做的string和wstring相互转换方法，经过大规模测试

    这段代码是从网上找的。但是，在实际使用中，出现了很多莫名奇妙的问题。后来多了修改，经过大规模的测试，表现良好。首先，感谢原作者，由于找不到链接了，不好意思，没能贴出链接地址。

 

 

size_t Dictionary::get_wchar_size(const char *str){size_t len = strlen(str); size_t size=0;size_t i;for(i=0; i < len; i++) { if( str[i] >= 0 && str[i] <= 127 ) //不是全角字符 { size+=sizeof(wchar_t); } else //是全角字符，是中文 { size+=sizeof(wchar_t); i+=2; }} return size;}char * Dictionary::w2c(const wchar_t *pw){if(!pw){ return NULL;}size_t size= wcslen(pw)*sizeof(wchar_t);char *pc;if(!(pc = (char*)malloc(size))){ printf("malloc fail"); return NULL;}wcstombs(pc,pw,size);return pc;}wchar_t * Dictionary::c2w(const char *pc){if(!pc){ return NULL; }size_t size_of_ch = strlen(pc)*sizeof(char);size_t size_of_wc = get_wchar_size(pc);wchar_t *pw;if(!(pw = (wchar_t*)malloc(size_of_wc))){ printf("malloc fail"); return NULL;}mbstowcs(pw,pc,size_of_wc);return pw;}std::wstring Dictionary::c2w_1(const char *pc){std::wstring val = L"";/*if(!pc){ return NULL; } */ if(NULL == pc) { return val; } size_t size_of_ch = strlen(pc)*sizeof(char);size_t size_of_wc = get_wchar_size(pc);//size_t size_of_wc;//assert(size_of_wc = get_wchar_size(pc));if(size_of_wc == 0){return val;}wchar_t * pw = new wchar_t[size_of_wc];mbstowcs(pw,pc,size_of_wc);val = pw;delete pw;return val;}