Ответ 1
Это будет следить за приходом и удалением USB-накопителей и сообщать о DriveLetter, метке тома и серийном номере устройства. Для вашего удобства он поднимает 2 события:
Public Event DeviceAdded(sender As Object, e As USBWatcherEventArgs)
Public Event DeviceRemoved(sender As Object, e As USBWatcherEventArgs)
Это касается только того, что новый диск добавлен/удален, он не будет обнаруживать такие вещи, как извлеченный или вставленный компакт-диск, или вставлять носитель в слот для считывания карт.
Imports System.Management
Public Class USBWatcher
' alternate method to use one event with an extra
' event property to report the action
'Public Enum WatcherActions
' DriveInserted = 1
' DriveRemoved = 2
'End Enum
' USB device added/removed args
Public Class USBWatcherEventArgs
Inherits EventArgs
'Public Property WatcherAction As WatcherActions
Public Property DriveLetter As String
Public Property VolumeName As String
Public Property VolumeSerial As String
Friend Sub New(drv As String, vol As String, ser As String)
DriveLetter = drv
VolumeName = vol
VolumeSerial = ser
'WatcherAction = act
End Sub
End Class
Private WithEvents Watcher As ManagementEventWatcher
Public Event DeviceAdded(sender As Object, e As USBWatcherEventArgs)
Public Event DeviceRemoved(sender As Object, e As USBWatcherEventArgs)
Private pnpCol As Dictionary(Of String, Management.ManagementObject)
Public Sub New()
End Sub
Public Sub StartWatching()
' get USBs currently attached
pnpCol = GetUSBDevices()
Dim arriveQuery = New WqlEventQuery("Select * from Win32_DeviceChangeEvent")
Watcher = New ManagementEventWatcher(arriveQuery)
' we are watching you
Watcher.Start()
End Sub
Public Sub StopWatching()
Watcher.Stop()
End Sub
Private Function GetUSBDevices() As Dictionary(Of String,
Management.ManagementObject)
Dim col As New Dictionary(Of String, Management.ManagementObject)
Dim moSearch As New Management.ManagementObjectSearcher("Select * from Win32_LogicalDisk")
Dim moReturn As Management.ManagementObjectCollection = moSearch.Get
For Each mo As Management.ManagementObject In moReturn
'Console.WriteLine("====")
'DebugProperties(mo)
' some USB external drives report as DriveType 3 (local disk), but are
' in fact removable. So monitor all disk drives.
If col.ContainsKey(mo("DeviceID").ToString) = False Then
col.Add(mo("DeviceID").ToString, mo)
End If
Next
Return col
End Function
Private inEvent As Boolean = False
Private Sub arrive_EventArrived(ByVal sender As Object,
ByVal e As System.Management.EventArrivedEventArgs) _
Handles Watcher.EventArrived
If inEvent Then Exit Sub
inEvent = True
Dim col As Dictionary(Of String, Management.ManagementObject) = GetUSBDevices()
Select Case col.Count
Case Is > pnpCol.Count
' device arrived
ProcessArrival(col)
Case Is < pnpCol.Count
' device removed
ProcessRemoval(col)
Case Is = pnpCol.Count
' noise...this is a chatty rascal
End Select
inEvent = False
End Sub
Private Sub ProcessArrival(col As Dictionary(Of String,
Management.ManagementObject))
For Each kvp As KeyValuePair(Of String,
Management.ManagementObject) In col
If pnpCol.ContainsKey(kvp.Key) = False Then
'Console.WriteLine("{0} {1} ", kvp.Key, kvp.Value)
'DebugProperties(kvp.Value)
Dim ea As New USBWatcherEventArgs(kvp.Value("DeviceID").ToString,
SafeString(kvp.Value("VolumeName")),
SafeString(kvp.Value("VolumeSerialNumber")))
RaiseEvent DeviceAdded(Me, ea)
'rebuild baseline for next event
pnpCol = col
End If
Next
End Sub
Private Sub ProcessRemoval(col As Dictionary(Of String,
Management.ManagementObject))
For Each kvp As KeyValuePair(Of String,
Management.ManagementObject) In pnpCol
If col.ContainsKey(kvp.Key) = False Then
'Console.WriteLine("{0} {1} ", kvp.Key, kvp.Value)
'DebugProperties(kvp.Value)
Dim ea As New USBWatcherEventArgs(kvp.Value("DeviceID").ToString,
SafeString(kvp.Value("VolumeName")),
SafeString(kvp.Value("VolumeSerialNumber")))
RaiseEvent DeviceRemoved(Me, ea)
'rebuild baseline for next event
pnpCol = col
End If
Next
End Sub
' lots of things can be NOTHING depending on the manufacturer's
' attention to detail. try to avoid NRE
Private Function SafeString(obj As Object) As String
If obj.GetType Is GetType(String) Then
Return CType(obj, String)
Else
If obj IsNot Nothing Then
Return obj.ToString
Else
Return "???"
End If
End If
End Function
' debug tool to poll a management object to get the properties and values
Private Sub DebugProperties(mo As Management.ManagementObject)
For Each pd As PropertyData In mo.Properties
If pd.Value IsNot Nothing Then
Console.WriteLine("{0} {1}", pd.Name,
If(pd.Value IsNot Nothing,
pd.Value.ToString,
"Nothing"))
End If
Next
End Sub
End Class
Как реализовать USBWatcher
' local variable to catch events
Private WithEvents watcher As USBWatcher
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
watcher = New USBWatcher
watcher.StartWatching() ' or add to a button click
' I DONT have it starting automatically when you create the watcher
End Sub
Наблюдатель устройств работает в другом потоке, поэтому, если вы хотите опубликовать уведомление для элемента управления, вам придется использовать делегат:
Delegate Sub AddListItem(text As String)
Private myDelegate As AddListItem = New AddListItem(AddressOf AddNewListItem)
Private Sub AddNewListItem(text As String)
myListBox.Items.Add(text)
End Sub
Затем из события Device Added, например:
Private Sub watcher_DeviceAdded(sender As Object,
e As USBWatcher.USBWatcherEventArgs) Handles watcher.DeviceAdded
Console.Beep()
Dim msg As String = String.Format("Drive {0} ({1}) {2}",
e.DriveLetter,
e.VolumeName, "Inserted")
If myListBox.InvokeRequired Then
myListBox.Invoke(myDelegate, New Object() {msg})
Else
myListBox.Items.Add(msg)
End If
End Sub
DeviceRemoved будет таким же, кроме "Удалено" в качестве третьего параметра в тексте сообщения.
USBWatcher также имеет метод StopWatching, чтобы отключить наблюдателя на время, и StartWatching, чтобы запустить и перезапустить его. Ваше приложение должно вызвать StopWatching, когда приложение закончится, чтобы предотвратить ошибки COM; просто добавьте watcher.StopWatching в событие закрытия формы.
Это делает то, что вы хотите - поднять события, когда вставлен съемный носитель, и вернуть информацию о них - просто не совсем так, как вы этого хотели. Он использует проверенную и проверенную WMI, а не метод Win8, который пока имеет только разреженный документ на MSDN и будет работать только на Win8.