MSDN：DeviceIoControl

與硬體驅動互動時，DeviceIoControl 是常用的windows API。 它把控制碼發給制定的硬體驅動，然後獲取裝置資訊或者對裝置進行其他操作。 下面是一個小demo

#include<iostream>
#include<windows.h>
using namespace std;


int main()
{
	TCHAR szDiskPos[128] = L"\\\\.\\PhysicalDrive0"; //ff
	HANDLE hDevice = INVALID_HANDLE_VALUE;
	int
 
 nDiskBufferSize = sizeof(PARTITION_INFORMATION_EX);
	PARTITION_INFORMATION_EX * lpDiskPartinfo_ex = (PARTITION_INFORMATION_EX *)malloc(nDiskBufferSize);
	DWORD nDiskBytesRead = 0;

	memset(lpDiskPartinfo_ex, 0, sizeof(lpDiskPartinfo_ex));

	hDevice = CreateFile(szDiskPos, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL
 
, OPEN_EXISTING, 0, NULL);
	BOOL Ret = FALSE;
    Ret = DeviceIoControl(hDevice, IOCTL_DISK_GET_PARTITION_INFO_EX, NULL, 0, lpDiskPartinfo_ex, nDiskBufferSize, &nDiskBytesRead, NULL);

	if(!Ret)
	{
		int e = GetLastError();
		cout<<strerror(e)<<endl;
	}
	if(lpDiskPartinfo_ex->PartitionStyle == PARTITION_STYLE_MBR )
	{
		cout
 
<<"MBR"<<endl;
	}else if(lpDiskPartinfo_ex->PartitionStyle == PARTITION_STYLE_GPT )
	{
		cout<<"GPT"<<endl;
	}else if(lpDiskPartinfo_ex->PartitionStyle == PARTITION_STYLE_RAW )
	{
		cout<<"RAW"<<endl;
	}
	free(lpDiskPartinfo_ex);
	lpDiskPartinfo_ex = NULL;
	CloseHandle(hDevice);

	cin.get();
	return 0;
}

這寫這個小demo的時候，犯了一個錯誤，使用了一個不再支援的控制碼IOCTL_DISK_GET_DRIVE_LAYOUT
而在MSDN上也已經警告過了

Note  IOCTL_DISK_GET_DRIVE_LAYOUT has been superseded by IOCTL_DISK_GET_DRIVE_LAYOUT_EX, which retrieves layout information for AT and EFI (Extensible Firmware Interface) partitions.

而我卻把這句話理解反了，使用IOCTL_DISK_GET_DRIVE_LAYOUT得不到想要的資料，雖然編譯是成功的，執行也沒有報錯，這導致後面浪費了好多時間。