Perform a lowercase comparison of strings.
函数原型：
int _stricmp( const char *string1, const char *string2 ); //#include <string.h>
int _wcsicmp( const wchar_t *string1, const wchar_t *string2 ); //#include <string.h> or <wchar.h>
int _mbsicmp( const unsigned char *string1, const unsigned char_t *string2 ); //#include <mbstring.h>
返回值：
0： string1 identical to string2 <0：string1 less than string2 >0：string1 greater than string2
举例：char *str1 = "abc";
char *str2 = "AbC";
int nResult = _stricmp(str1, str2); //nResult = 0
wchar_t szStr1[] = "asdfg";
wchar_t szStr2[] = "AsDfG";
int nResult = _wcsicmp(szStr1, szStr2); //nResult = 0
至于_mbsicmp是比较无符号字符串的，可根据情况自行使用