C语言字符串编码方式转换

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <Windows.h>
#include <locale.h>

wchar_t *ANSITOUnicode(const char* str){
int textlen = 0;
wchar_t *result = NULL;
textlen = MultiByteToWideChar(CP_ACP,0,str,-1,NULL,0);
result = (wchar_t*)malloc((textlen+1)*sizeof(wchar_t));
memset(result,0,(textlen+1)*sizeof(wchar_t));
MultiByteToWideChar(CP_ACP,0,str,-1,(LPWSTR)result,textlen);
return result;
}

char *UnicodeToANSI(const wchar_t *str){
char *result = NULL;
int textlen = 0;
textlen = WideCharToMultiByte(CP_ACP,0,str,-1,NULL,0,NULL,NULL);
result = (char*)malloc((textlen+1)*sizeof(char));
memset(result,0,sizeof(char)*(textlen+1));
WideCharToMultiByte(CP_ACP,0,str,-1,result,textlen,NULL,NULL);
return result;
}

wchar_t *Utf8ToUnicode(const char* str){
int textlen = 0;
wchar_t *result = NULL;
textlen = MultiByteToWideChar(CP_UTF8,0,str,-1,NULL,0);
result = (wchar_t *)malloc((textlen+1)*sizeof(wchar_t));
memset(result,0,(textlen+1)*sizeof(wchar_t));
MultiByteToWideChar(CP_UTF8,0,str,-1,(LPWSTR)result,textlen);
return result;
}

char* UnicodeToUTF8(const wchar_t* str){
char *result = NULL;
int textlen = 0;
textlen = WideCharToMultiByte(CP_UTF8,0,str,-1,NULL,0,NULL,NULL);
result = (char*)malloc((textlen+1)*sizeof(char));
memset(result,0,sizeof(char)*(textlen+1));
WideCharToMultiByte(CP_UTF8,0,str,-1,result,textlen,NULL,NULL);
return result;
}

wchar_t* m2w(const char* mbs){
int len = 0;
wchar_t* buf;
len = mbstowcs(NULL,mbs,0);
if (len == 0)
return NULL;
buf = (wchar_t*)malloc(sizeof(wchar_t)*(len+1));
memset(buf,0,sizeof(wchar_t*)*(len+1));
len = mbstowcs(buf,mbs,len+1);
return buf;
}

char* ANSIToUTF8(const char* str){
return UnicodeToUTF8(ANSITOUnicode(str));
}

char* UTF8ToANSI(const char* str){
return UnicodeToANSI(Utf8ToUnicode(str));
}