高人帮看看，MSDN上的C代码为什么在我机器上不起作用？

2010-11-08 08:22:02 189 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

VC++ MSDN离线帮助文档安装配置全攻略在软件开发中，离线文档系统是保障开发效率与稳定性的重要基础设施，尤其对于依赖特定技术栈的工程实践。其核心原理在于将权威的技术知识库本地化，通过索引与查询技术实现快速检索，从而消除网络依赖带来的不确定性。对于Windows平台下的Visual C++开发而言，MSDN离线帮助文档的技术价值尤为突出，它不仅是API查询工具，更是涵盖MFC、ATL、CRT及Windows SDK等核心技术的完整知识体系。在**内网开发环境**或**遗留系统维护**场景中，网络不稳定或封闭性要求使得离线文档成为刚需。通过正确获取、阅读详情

代码源自： http://support.microsoft.com/kb/165721/zh-cn

我在BCB中建立了一个控制台程序：
#include <windows.h>
#include <winioctl.h>
#include <tchar.h>
#include <stdio.h>

// Prototypes

BOOL EjectVolume(TCHAR cDriveLetter);

HANDLE OpenVolume(TCHAR cDriveLetter);
BOOL LockVolume(HANDLE hVolume);
BOOL DismountVolume(HANDLE hVolume);
BOOL PreventRemovalOfVolume(HANDLE hVolume, BOOL fPrevent);
BOOL AutoEjectVolume(HANDLE hVolume);
BOOL CloseVolume(HANDLE hVolume);

LPTSTR szVolumeFormat = TEXT("\\\\.\\%c:");
LPTSTR szRootFormat = TEXT("%c:\\");
LPTSTR szErrorFormat = TEXT("Error %d: %s\n");

void ReportError(LPTSTR szMsg)
{
_tprintf(szErrorFormat, GetLastError(), szMsg);
}

HANDLE OpenVolume(TCHAR cDriveLetter)
{
HANDLE hVolume;
UINT uDriveType;
TCHAR szVolumeName[8];
TCHAR szRootName[5];
DWORD dwAccessFlags;

wsprintf(szRootName, szRootFormat, cDriveLetter);

uDriveType = GetDriveType(szRootName);
switch(uDriveType) {
case DRIVE_REMOVABLE:
dwAccessFlags = GENERIC_READ | GENERIC_WRITE;
break;
case DRIVE_CDROM:
dwAccessFlags = GENERIC_READ;
break;
default:
_tprintf(TEXT("Cannot eject. Drive type is incorrect.\n"));
return INVALID_HANDLE_VALUE;
}

wsprintf(szVolumeName, szVolumeFormat, cDriveLetter);

hVolume = CreateFile( szVolumeName,
dwAccessFlags,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
0,
NULL );
if (hVolume == INVALID_HANDLE_VALUE)
ReportError(TEXT("CreateFile"));

return hVolume;
}

BOOL CloseVolume(HANDLE hVolume)
{
return CloseHandle(hVolume);
}

#define LOCK_TIMEOUT 10000 // 10 Seconds
#define LOCK_RETRIES 20

BOOL LockVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;
DWORD dwSleepAmount;
int nTryCount;

dwSleepAmount = LOCK_TIMEOUT / LOCK_RETRIES;

// Do this in a loop until a timeout period has expired
for (nTryCount = 0; nTryCount < LOCK_RETRIES; nTryCount++) {
if (DeviceIoControl(hVolume,
FSCTL_LOCK_VOLUME,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL))
return TRUE;

Sleep(dwSleepAmount);
}

return FALSE;
}

BOOL DismountVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;

return DeviceIoControl( hVolume,
FSCTL_DISMOUNT_VOLUME,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL);
}

BOOL PreventRemovalOfVolume(HANDLE hVolume, BOOL fPreventRemoval)
{
DWORD dwBytesReturned;
PREVENT_MEDIA_REMOVAL PMRBuffer;

PMRBuffer.PreventMediaRemoval = fPreventRemoval;

return DeviceIoControl( hVolume,
IOCTL_STORAGE_MEDIA_REMOVAL,
&PMRBuffer, sizeof(PREVENT_MEDIA_REMOVAL),
NULL, 0,
&dwBytesReturned,
NULL);
}

AutoEjectVolume(HANDLE hVolume)
{
DWORD dwBytesReturned;

return DeviceIoControl( hVolume,
IOCTL_STORAGE_EJECT_MEDIA,
NULL, 0,
NULL, 0,
&dwBytesReturned,
NULL);
}

BOOL EjectVolume(TCHAR cDriveLetter)
{
HANDLE hVolume;

BOOL fRemoveSafely = FALSE;
BOOL fAutoEject = FALSE;

// Open the volume.
hVolume = OpenVolume(cDriveLetter);
if (hVolume == INVALID_HANDLE_VALUE)
return FALSE;

// Lock and dismount the volume.
if (LockVolume(hVolume) && DismountVolume(hVolume)) {
fRemoveSafely = TRUE;

// Set prevent removal to false and eject the volume.
if (PreventRemovalOfVolume(hVolume, FALSE) &&
AutoEjectVolume(hVolume))
fAutoEject = TRUE;
}

// Close the volume so other processes can use the drive.
if (!CloseVolume(hVolume))
return FALSE;

if (fAutoEject)
printf("Media in Drive %c has been ejected safely.\n",
cDriveLetter);
else {
if (fRemoveSafely)
printf("Media in Drive %c can be safely removed.\n",
cDriveLetter);
}

return TRUE;
}

void Usage()
{
printf("Usage: Eject <drive letter>\n\n");
return ;
}

void main(int argc, char * argv[])
{
if (argc != 2) {
Usage();
return ;
}

if (!EjectVolume(argv[1][0]))
printf("Failure ejecting drive %c.\n", argv[1][0]);

return ;
}

我的USB盘为“G”盘，
编译后我执行:
Project1.exe G
结果显示：Media in Drive G has been ejected safely.
但我到我的电脑中看见，这个“G”盘依然存在，还能打开访问里面的内容，为什么会这样？

...全文