用win32 API监听U盘插拔并取得其盘符/取得当前插入U盘的盘符

用win32 API监听U盘插拔并取得其盘符

1.使用RegisterDeviceNotification()函数注册

static const GUID GUID_DEVINTERFACE_USB_DEVICE =
{0xA5DCBF10, 0x6530, 0x11D2, {0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED}};

void RegisterDeviceNotify()
{
HDEVNOTIFY hDevNotify;
DEV_BROADCAST_DEVICEINTERFACE NotificationFilter;
ZeroMemory( &NotificationFilter, sizeof(NotificationFilter) );
NotificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
NotificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
NotificationFilter.dbcc_classguid = GUID_DEVINTERFACE_USB_DEVICE;
hDevNotify = RegisterDeviceNotification(hWnd, &NotificationFilter, DEVICE_NOTIFY_WINDOW_HANDLE);
}

2.在WndProc()函数中接收WM_DEVICECHANGE消息

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch(message)
{
case WM_DEVICECHANGE:
return DeviceChange(message, wParam, lParam);
}

return DefWindowProc(hWnd, message, wParam, lParam);
}

3.处理接收到的WM_DEVICECHANGE消息

char FirstDriveFromMask(ULONG unitmask)
{
char i;

for (i = 0; i < 26; ++i)
{
if (unitmask & 0x1)
break;
unitmask >>= 1;
}

return (i + 'A');
}

LRESULT DeviceChange(UINT message, WPARAM wParam, LPARAM lParam)
{
if ( DBT_DEVICEARRIVAL == wParam || DBT_DEVICEREMOVECOMPLETE == wParam )
{
PDEV_BROADCAST_HDR pHdr = (PDEV_BROADCAST_HDR)lParam;
if (pHdr->dbch_devicetype == DBT_DEVTYP_VOLUME)
{
PDEV_BROADCAST_VOLUME pDevVolume = (PDEV_BROADCAST_VOLUME)lParam;
char driverLabel = FirstDriveFromMask(pDevVolume->dbcv_unitmask);
if (wParam == DBT_DEVICEARRIVAL) {
printf("add %c\r\n", driverLabel);
} else {
printf("remove %c\r\n", driverLabel);
}
}
}
return 0;
}

用win32 API取得当前插入U盘的盘符

1.使用GetLogicalDrives()取得代表各分区的掩码

DWORD mask = GetLogicalDrives();

2.遍历掩码的每一位，判断对应的分区是否是U盘

bool IsUsbDevice(wchar_t letter)
{
wchar_t volumeAccessPath[] = L"\\\\.\\X:";
volumeAccessPath[4] = letter;

HANDLE deviceHandle = CreateFile(
volumeAccessPath,
0,                // no access to the drive
FILE_SHARE_READ | // share mode
FILE_SHARE_WRITE,
NULL,             // default security attributes
OPEN_EXISTING,    // disposition
0,                // file attributes
NULL);            // do not copy file attributes

// setup query
STORAGE_PROPERTY_QUERY query;
memset(&query, 0, sizeof(query));
query.PropertyId = StorageDeviceProperty;
query.QueryType = PropertyStandardQuery;

// issue query
DWORD bytes;
STORAGE_DEVICE_DESCRIPTOR devd;
STORAGE_BUS_TYPE busType = BusTypeUnknown;

if (DeviceIoControl(deviceHandle,
IOCTL_STORAGE_QUERY_PROPERTY,
&query, sizeof(query),
&devd, sizeof(devd),
&bytes, NULL))
{
busType = devd.BusType;
}

CloseHandle(deviceHandle);

return BusTypeUsb == busType;
}

// 查找U盘
// 参数:  _letter 存储U盘盘符
// 返回值:true 当前有U盘
//       false 当前无U盘
bool findUSBStorage(char* _letter)
{
DWORD mask = GetLogicalDrives();
int count = 0;
while (mask != 0)
{
if ((mask & 0x01) == 1)
{
wchar_t letter = L'A' + count;

// 判断取得的盘符是否是U盘
if (IsUsbDevice(letter))
{
wcstombs(_letter, &letter, 1);
return true;
}
}
count++;
mask = mask >> 1;
}
return false;
}