Cstring转换成char*函数

char * CStringtochar(CString str)
{
         
	char *ptr;    
#ifdef _UNICODE    
	LONG len;    
	len = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);    
	ptr = new char [len+1];    memset(ptr,0,len + 1);    
	WideCharToMultiByte(CP_ACP, 0, str, -1, ptr, len + 1, NULL, NULL);    
#else    
	ptr = new char [str.GetAllocLength()+1];    
	sprintf(ptr,_T("%s"),str);    
#endif    
	return ptr;
}