Retrieving dbcc_name string from a DEV_BROADCAST_DEVICEINTERFACE structure

**Willy Denoyette [MVP]** · Nov 16 '05, 03:33 AM

Re: Retrieving dbcc_name string from a DEV_BROADCAST_D EVICEINTERFACE structure

Not directly a code translation, but another way to achieve the same (or
better) result.
Using System.Manageme nt classes, you can install an event listener for USB
device controller events, these events are generated when USB devices are
connected. Note that every USB device consists of at least one or more
devices, for instance a USB disk generates 3 events when connected.

Following is a complete sample, just compile and try it out.

// This code demonstrates how to monitor the UsbControllerDe vice for
// the arrival of pnp device creation/operation events
using System;
using System.Componen tModel;
using System.Runtime. InteropServices ;
using System.Manageme nt;
class WMIEvent {
public static void Main() {
USBEvent usbEvnt = new USBEvent();
usbEvnt.Start() ;
Console.ReadLin e(); // block main thread for test purposes
usbEvnt.Stop();
}
}

internal class USBEvent
{
ManagementEvent Watcher w= null;

internal void Start()
{
// Bind to local machine
try {
WqlEventQuery q = new WqlEventQuery() ;
q.EventClassNam e = "__InstanceOper ationEvent";
q.WithinInterva l = new TimeSpan(0,0,3) ;
q.Condition = @"TargetInstanc e ISA 'Win32_USBContr ollerDevice' ";
w = new ManagementEvent Watcher(q);
w.EventArrived += new EventArrivedEve ntHandler(this. UsbEventArrived );
w.Start(); // Start listen for events
}
catch(Exception e) {this.Stop();}
}
internal void Stop() {
w.EventArrived -= new EventArrivedEve ntHandler(this. UsbEventArrived );
w.Stop();
w.Dispose();
}
public void UsbEventArrived (object sender, EventArrivedEve ntArgs e) {
//Get the Event object and display all it properties
ManagementBaseO bject mbo =
(ManagementBase Object)e.NewEve nt["TargetInstance "];
using(Managemen tObject o = new
ManagementObjec t(mbo["Dependent"].ToString()))
{
o.Get();
if (o.Properties.C ount == 0)
{
Console.WriteLi ne("No further device properties, device removed?");
}
foreach(Propert yData prop in o.Properties)
Console.WriteLi ne("{0} - {1}", prop.Name, prop.Value);
Console.WriteLi ne("-------------------------------");
}
}
}

Willy.

"Jeffrey B. Holtz" <jholtz@accurat etechnologies.c om> wrote in message
news:937be330.0 404281136.53350 bb1@posting.goo gle.com...[color=blue]
> I'm trying to get the Name of the USB device pluged in from the
> RegisterDeviceN otification that I've used P/Invoke to marshal. I have
> seen a similar posting on the VisualBasic newgroups but I do not know
> how to translate the ReDim that occurs there into C#. Or wither this
> will actually give me what I'm looking for.
> The code I'm posting seems to work although I don't know how to
> set the length of the name correctly in the Marshal.PtrToSt ructure()
> call.
>
> Thanks all for any help.
> Hopefully this VB->VC translation can help someone out there as well
>
> Jeff
>
>
> Visual Basic Code:
> =============== ===
> Imports System.Runtime. InteropServices
> Imports System.Windows. Forms
> Imports System.Text
> Public Class Form1
> Inherits System.Windows. Forms.Form
>
> Public Class Win32
> Public Const WM_DEVICECHANGE = &H219
> Public Const DBT_DEVICEARRIV AL = &H8000
> Public Const DBT_DEVICEREMOV ECOMPLETE = &H8004
> Public Const DEVICE_NOTIFY_W INDOW_HANDLE = 0
> Public Const DEVICE_NOTIFY_S ERVICE_HANDLE = 1
> Public Const DBT_DEVTYP_DEVI CEINTERFACE = 5
> Public Shared GUID_IO_MEDIA_A RRIVAL As Guid = New
> Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED")
>
> <StructLayout(L ayoutKind.Seque ntial)> _
> Public Class DEV_BROADCAST_D EVICEINTERFACE
> Public dbcc_size As Integer
> Public dbcc_devicetype As Integer
> Public dbcc_reserved As Integer
> Public dbcc_classguid As Guid
> Public dbcc_name As Short
> End Class
> <StructLayout(L ayoutKind.Seque ntial,
> CharSet:=CharSe t.Unicode)> _
> Public Class DEV_BROADCAST_D EVICEINTERFACE1
> Public dbcc_size As Integer
> Public dbcc_devicetype As Integer
> Public dbcc_reserved As Integer
> <MarshalAs(Unma nagedType.ByVal Array,
> ArraySubType:=U nmanagedType.U1 , SizeConst:=16)> _
> Public dbcc_classguid( ) As Byte
> <MarshalAs(Unma nagedType.ByVal Array, SizeConst:=128) > _
> Public dbcc_name() As Char
> End Class
> <StructLayout(L ayoutKind.Seque ntial)> _
> Public Class DEV_BROADCAST_H DR
> Public dbcc_size As Integer
> Public dbcc_devicetype As Integer
> Public dbcc_reserved As Integer
> End Class
>
> <DllImport("use r32.DLL", SetLastError:=T rue)> _
> Public Shared Function _
> RegisterDeviceN otification(ByV al IntPtr As IntPtr, ByVal
> NotificationFil ter As IntPtr, ByVal Flags As Int32) As IntPtr
> End Function
>
> <DllImport("ker nel32.DLL")> _
> Public Shared Function _
> GetLastError() As Integer
> End Function
> End Class
>
> Public Sub New()
> MyBase.New()
> InitializeCompo nent()
> RegisterHidNoti fication()
> End Sub
>
> Public Sub RegisterHidNoti fication()
> Dim dbi As Win32.DEV_BROAD CAST_DEVICEINTE RFACE = New
> Win32.DEV_BROAD CAST_DEVICEINTE RFACE
> Dim size As Integer
> size = Marshal.SizeOf( dbi)
> Dim gd As Guid
> ' MsgBox(Marshal. SizeOf(gd))
> ' MsgBox(Marshal. SizeOf(New
> Win32.DEV_BROAD CAST_DEVICEINTE RFACE1))
> dbi.dbcc_size = size
> dbi.dbcc_device type = Win32.DBT_DEVTY P_DEVICEINTERFA CE
> dbi.dbcc_reserv ed = 0
> dbi.dbcc_classg uid = Win32.GUID_IO_M EDIA_ARRIVAL
> Dim Buffer As IntPtr
> Buffer = Marshal.AllocHG lobal(size)
> Marshal.Structu reToPtr(dbi, Buffer, True)
> Dim r As IntPtr
> r = Win32.RegisterD eviceNotificati on(Handle, Buffer,
> Win32.DEVICE_NO TIFY_WINDOW_HAN DLE)
> Marshal.PtrToSt ructure(Buffer, dbi)
> If r.ToInt32 = IntPtr.Zero.ToI nt32 Then
> MessageBox.Show (Win32.GetLastE rror().ToString ())
> End If
> End Sub
>
> Protected Overrides Sub WndProc(ByRef m As Message)
> If m.Msg = Win32.WM_DEVICE CHANGE Then
> OnDeviceChange( m)
> End If
> MyBase.WndProc( m)
> End Sub
>
> Private Sub OnDeviceChange( ByVal msg As Message)
> Dim wParam As Integer
> wParam = msg.WParam.ToIn t32()
> If wParam = Win32.DBT_DEVIC EARRIVAL Then
> Dim o As New Win32.DEV_BROAD CAST_HDR
> Dim b As New Win32.DEV_BROAD CAST_DEVICEINTE RFACE1
> Dim gd As Guid
> Marshal.PtrToSt ructure(msg.LPa ram, o)
> If (o.dbcc_devicet ype = Win32.DBT_DEVTY P_DEVICEINTERFA CE)
> Then
> Dim strsize As Integer = (o.dbcc_size - 28) / 2
> ReDim b.dbcc_name(str size)
> Marshal.PtrToSt ructure(msg.LPa ram, b)
> MsgBox(New Guid(b.dbcc_cla ssguid).ToStrin g)
> Dim str As New String(b.dbcc_n ame, 0, strsize)
> MsgBox(str)
> End If
> MessageBox.Show ("Arrival")
> ElseIf wParam = Win32.DBT_DEVIC EREMOVECOMPLETE Then
> MessageBox.Show ("Remove")
> End If
> End Sub
>
> 'Form overrides dispose to clean up the component list.
> Protected Overloads Overrides Sub Dispose(ByVal disposing As
> Boolean)
> If disposing Then
> If Not (components Is Nothing) Then
> components.Disp ose()
> End If
> End If
> MyBase.Dispose( disposing)
> End Sub
>
> 'Required by the Windows Form Designer
> Private components As System.Componen tModel.IContain er
>
> 'NOTE: The following procedure is required by the Windows Form
> Designer
> 'It can be modified using the Windows Form Designer.
> 'Do not modify it using the code editor.
> <System.Diagnos tics.DebuggerSt epThrough()> Private Sub
> InitializeCompo nent()
> components = New System.Componen tModel.Containe r
> Me.Text = "Form1"
> Dim t As New Guid("d07433c0-a98e-11d2-917a-00a0c9068ff3")
> End Sub
> End Class
>
>
> Visual CSharp Equivilent
> =============== =========
> using System;
> using System.Drawing;
> using System.Collecti ons;
> using System.Componen tModel;
> using System.Windows. Forms;
> using System.Data;
> using System.Runtime. InteropServices ;
>
> namespace WindowsApplicat ion1
> {
> /// <summary>
> /// Summary description for Form1.
> /// </summary>
> public class Form1 : System.Windows. Forms.Form
> {
> private System.Componen tModel.Containe r components = null;
>
> public Form1()
> {
> InitializeCompo nent();
> RegisterDeviceN otification();
> }
>
> private void InitializeCompo nent()
> {
> this.components = new System.Componen tModel.Containe r();
> this.Size = new System.Drawing. Size(300,300);
> this.Text = "Form1";
> }
>
> [STAThread] static void Main()
> {
> Application.Run (new Form1());
> }
>
> void RegisterDeviceN otification()
> {
> Win32.DEV_BROAD CAST_DEVICEINTE RFACE dbi = new
> Win32.DEV_BROAD CAST_DEVICEINTE RFACE();
> int size = Marshal.SizeOf( dbi);
> dbi.dbcc_size = size;
> dbi.dbcc_device type = Win32.DBT_DEVTY P_DEVICEINTERFA CE;
> dbi.dbcc_reserv ed = 0;
> dbi.dbcc_classg uid = Win32.GUID_DEVI NTERFACE_USB_DE VICE;
> dbi.dbcc_name = 0;
> IntPtr buffer = Marshal.AllocHG lobal(size);
> Marshal.Structu reToPtr(dbi, buffer, true);
> IntPtr r = Win32.RegisterD eviceNotificati on(Handle, buffer,
> Win32.DEVICE_NO TIFY_WINDOW_HAN DLE);
> if(r == IntPtr.Zero)
> MessageBox.Show (Win32.GetLastE rror().ToString ());
> }
> protected override void WndProc(ref Message m)
> {
> switch(m.Msg)
> {
> case Win32.WM_DEVICE CHANGE: OnDeviceChange( ref m); break;
> }
> base.WndProc (ref m);
> }
> void OnDeviceChange( ref Message msg)
> {
> int wParam = (int)msg.WParam ;
> if((wParam == Win32.DBT_DEVIC EARRIVAL) || (wParam ==
> Win32.DBT_DEVIC EREMOVECOMPLETE ))
> {
> // Read the dhdr.dbcc_devic etype - The Following code could also
> be used
> ////////////////////////////////////////////////////////////////////////
> //Win32.DEV_BROAD CAST_HDR dhdr;
> //dhdr = (Win32.DEV_BROA DCAST_HDR)
> Marshal.PtrToSt ructure(msg.LPa ram,typeof(Win3 2.DEV_BROADCAST _HDR));
> //if (dhdr.dbcc_devi cetype == Win32.DBT_DEVTY P_DEVICEINTERFA CE)
> int dbccSize = Marshal.ReadInt 32(msg.LParam,0 );
> int devType = Marshal.ReadInt 32(msg.LParam,4 );
>
> if(devType == Win32.DBT_DEVTY P_DEVICEINTERFA CE)
> {
> Win32.DEV_BROAD CAST_DEVICEINTE RFACE1 dip;
> dip = (Win32.DEV_BROA DCAST_DEVICEINT ERFACE1)
> Marshal.PtrToSt ructure(msg.LPa ram,typeof(Win3 2.DEV_BROADCAST _DEVICEINTERFAC E1));
> string csTemp = new string(dip.dbcc _name);
> MessageBox.Show (csTemp + " arrived/removed");
> }
> }
> }
> }
> public class Win32
> {
> public const int WM_DEVICECHANGE = 0x0219;
> public const int DBT_DEVICEARRIV AL = 0x8000, // system
> detected a new device
> DBT_DEVICEREMOV ECOMPLETE = 0x8004; // device is gone
> public const int DEVICE_NOTIFY_W INDOW_HANDLE = 0,
> DEVICE_NOTIFY_S ERVICE_HANDLE = 1;
> public const int DBT_DEVTYP_DEVI CEINTERFACE = 0x00000005; // device
> interface class
> public static Guid GUID_DEVINTERFA CE_USB_DEVICE = new
> Guid("A5DCBF10-6530-11D2-901F-00C04FB951ED");
>
> [StructLayout(La youtKind.Sequen tial)] public class DEV_BROADCAST_H DR
> {
> public int dbcc_size;
> public int dbcc_devicetype ;
> public int dbcc_reserved;
> }
> [StructLayout(La youtKind.Sequen tial)] public class
> DEV_BROADCAST_D EVICEINTERFACE
> {
> public int dbcc_size;
> public int dbcc_devicetype ;
> public int dbcc_reserved;
> public Guid dbcc_classguid;
> public short dbcc_name;
> }
>
> [StructLayout(La youtKind.Sequen tial, CharSet=CharSet .Unicode)]
> public class DEV_BROADCAST_D EVICEINTERFACE1
> {
> public int dbcc_size;
> public int dbcc_devicetype ;
> public int dbcc_reserved;
> [MarshalAs(Unman agedType.ByValA rray, ArraySubType=Un managedType.U1,
> SizeConst=16)] public byte [] dbcc_classguid;
> [MarshalAs(Unman agedType.ByValA rray, SizeConst=128)] public char []
> dbcc_name;
> }
>
> [DllImport("user 32.dll", SetLastError=tr ue)] public static extern
> IntPtr RegisterDeviceN otification( IntPtr hRecipient, IntPtr
> NotificationFil ter, Int32 Flags);
> [DllImport("kern el32.dll")] public static extern int GetLastError();
> }
>
> }[/color]

Retrieving dbcc_name string from a DEV_BROADCAST_DEVICEINTERFACE structure

Retrieving dbcc_name string from a DEV_BROADCAST_DEVICEINTERFACE structure

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