Help with USB & DEVICEARRIVAL
in [VB.NET]
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From: malcomm on 14 Sep 2009 22:40 Hi I'm writing a small application to detect the insertion of USB memory sticks and prompt the user to accept the device or reject it. Rejecting would prevent its being loaded by Windows. I have the code that detects insertion & removal working fine but have no idea how to cancel the insertion. I was thinking that I could intercept the DEVICEARRIVAL message and kill it off before its actioned by Windows but I am lost with this. Has anyone got and ideas on this. I'd really appreciate some sample vb.net code to show the way. Heres the main part of the code I have so far- Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message) 'This kills off any 'autoplay' capability in the stick If QueryCancelAutoPlay = 0 Then QueryCancelAutoPlay = RegisterWindowMessage("QueryCancelAutoPlay") End If If m.Msg = WM_DEVICECHANGE Then Select Case m.WParam Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEARRIVAL ProcessUSB() Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEREMOVECOMPLETE lblMessage.Text = "USB Removed" End Select ElseIf m.Msg = QueryCancelAutoPlay Then m.Result = CType(1, IntPtr) Return End If MyBase.WndProc(m) End Sub Private Sub ProcessUSB() For Each ThisDrive As System.IO.DriveInfo In My.Computer.FileSystem. Drives If ThisDrive.DriveType.ToString = "Removable" Then 'Prompt user for accept/reject etc lblMessage.Text = "USB Inserted" End If Next End Sub many thanks malcom
From: Alex Clark on 15 Sep 2009 01:19 Hi Malcomm, I doubt that intercepting & swalling the DEVICEARRIVAL message would do you any good, as it's basically a courtesy message broadcast by Windows so that apps can respond to it. At this stage the device has already been connected & recognised. What you could do at this point is react by checking the USB memory stick and if it violates your business-logic rule, perhaps use a WMI command to "eject" it. A quick Google for "wmi eject usb" throws up loads of useful looking results, some of which are C# based and could likely be converted easily. HTH, Alex "malcomm" <u54785(a)uwe> wrote in message news:9c2280f5224eb(a)uwe... > Hi > > I'm writing a small application to detect the insertion of USB memory > sticks > and prompt the user to accept the device or reject it. Rejecting would > prevent its being loaded by Windows. > > I have the code that detects insertion & removal working fine but have no > idea how to cancel the insertion. > I was thinking that I could intercept the DEVICEARRIVAL message and kill > it > off before its actioned by Windows but I am lost with this. > Has anyone got and ideas on this. I'd really appreciate some sample vb.net > code to show the way. > > Heres the main part of the code I have so far- > > Protected Overrides Sub WndProc(ByRef m As > System.Windows.Forms.Message) > 'This kills off any 'autoplay' capability in the stick > If QueryCancelAutoPlay = 0 Then > QueryCancelAutoPlay = > RegisterWindowMessage("QueryCancelAutoPlay") > > End If > > If m.Msg = WM_DEVICECHANGE Then > Select Case m.WParam > Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEARRIVAL > ProcessUSB() > Case WM_DEVICECHANGE_WPPARAMS.DBT_DEVICEREMOVECOMPLETE > lblMessage.Text = "USB Removed" > End Select > ElseIf m.Msg = QueryCancelAutoPlay Then > m.Result = CType(1, IntPtr) > Return > End If > MyBase.WndProc(m) > End Sub > > Private Sub ProcessUSB() > For Each ThisDrive As System.IO.DriveInfo In > My.Computer.FileSystem. > Drives > If ThisDrive.DriveType.ToString = "Removable" Then > 'Prompt user for accept/reject etc > lblMessage.Text = "USB Inserted" > End If > Next > End Sub > > > many thanks > malcom >
From: malcomm on 15 Sep 2009 01:42
Thanks Alex I'll delve into that and see what trouble I can get into. Cheers malcom |