用Windows API进行字符串或字符的大小写转换

#include <iostream>
#include <windows.h>

using namespace std;

int main()
{
 char sz[100] = "aBcDefGHIJklmn";
 cout << sz << endl;
 ::CharLowerA(&sz[0]);
 cout << sz << endl;
 ::CharUpperA(&sz[0]);
 cout << sz << endl;
 bool upper(true);
 for (unsigned i = 0; i < strlen(sz); ++i)
 {
  if (upper)
   ::CharUpperA(&sz[i]);
  else ::CharLowerA(&sz[i]);
  upper = !upper;
 }
 cout << sz << endl;
 return 0;
}