GetWindowsDirectoryA and GetSystemDirectory

#include <iostream>
#include <Windows.h>

using std::cout;
using std::endl;

// 获取Windows文件夹的路径
//UINT GetWindowsDirectory(LPTSTR lpBuffer,UINT uSize)

//获取systrm32文件夹的路径
//UINT GetSystemDirectory(LPTSTR lpBuffer,UINT uSize)

//这两个函数的使用方法很简单，和以前一样有两种方法来确定缓冲区的长度：
//1、Windows定义了一个文件路径的最长长度的常量MAX_PATH(值为260)，我们可以用它来建立字符串缓冲区；
//2、给缓冲区传入NULL，调用函数成功后将返回缓冲区的长度。


int main()
{
    char* buf = nullptr;
    // 调用成功后，返回缓冲区的长度,返回windows文件夹的路径
    UINT Size = GetWindowsDirectory(NULL,0);
    buf = new char [Size];
    cout << Size << endl;
    if(0 != GetWindowsDirectoryA(buf,Size))
        cout << "WindowsDirectory path is :" << endl << buf << endl;
    else
        cout << "failed. GetLastError() :" << GetLastError() << endl;
    delete buf;
    buf = nullptr;
    cout << endl;

    // 调用成功后，返回缓冲区的长度，返回系统路径
    Size = GetSystemDirectory(NULL,0);
    buf = new char [Size];
    cout << Size << endl;
    if(0 != GetSystemDirectoryA(buf,Size))
        cout << "WindowsDirectory path is :" << endl << buf << endl;
    else
        cout << "failed. GetLastError() :" << GetLastError() << endl;
    delete buf;
    buf = nullptr;
    cout << endl;

    system("pause");
    return 0;
}