C++ GetSystemDirectory()
关于GetSystemDirectory function，参考：https://msdn.microsoft.com/en-us/library/windows/desktop/ms724373(v=vs.85).aspx
以下代码摘自Getting System Information（https://msdn.microsoft.com/en-us/library/windows/desktop/ms724426(v=vs.85).aspx）。
IDE: Microsoft Visual Studio Community 2017 15.5.2
操作系统：Windows 7 x64
1 #include "stdafx.h" /* IDE自行创建的 */ 2 3 #include <windows.h> 4 5 #define INFO_BUFFER_SIZE 21 6 7 int main(int argc, char **argv) 8 { 9 TCHAR infoBuf[INFO_BUFFER_SIZE]; 10 UINT RetSize; 11 12 RetSize = GetSystemDirectory(infoBuf, INFO_BUFFER_SIZE); 13 // RetSize = 0; 14 if ((RetSize != 0) && (RetSize <= INFO_BUFFER_SIZE)) { 15 // If the function succeeds, the return value is the length, in TCHARs, of the string copied to the buffer, 16 // not including the terminating null character. 17 18 // Display the system directory. 19 printf("System Directory: %ls", infoBuf); 20 } 21 else if (RetSize > INFO_BUFFER_SIZE) { 22 // If the length is greater than the size of the buffer, 23 // the returnv alue is the size of the buffer required to hold the path, 24 // including the terminating null character. 25 printf("The size of the buffer is not enough, need %d TCHARs at least. \n", RetSize); 26 } 27 else { 28 // If the function fails, the return value is zero. To get extended error information, call GetLastError. 29 printf("Get system directory failed with error: %d", GetLastError()); 30 } 31 32 getchar(); 33 34 return 0; 35 }
可以修改INFO_BUFFER_SIZE的值，改变程序的运行结果。
也可以去掉RetSize = 0;前面的注释，模拟错误（实际上不是错误，我只是用来测试if语句的条件）。
不知道是否存在BUG？？？
