How to get whether a speaker plugged or unplugged - vb.net

Question

I use Visual Studio 2013 for Visual Basic and I want to be able to test whether a speaker is plugged in or unplugged from the speaker jack. Is it possible?

Answer 1

It can be done with Device Topology API. IKsJackDescription interface can be used to get KSJACK_DESCRIPTION structure, which has IsConnected member. However, not every device supports cable presence detection, in case it doesn't the API will always report it's connected.
COM objects declarations
Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Runtime.InteropServices
Imports System.IO
Imports System.Runtime.CompilerServices
Namespace com_test
Class Native
<DllImport("ole32.Dll")> _
Public Shared Function CoCreateInstance(ByRef clsid As Guid, <MarshalAs(UnmanagedType.IUnknown)> inner As Object, context As UInteger, ByRef uuid As Guid, <MarshalAs(UnmanagedType.IUnknown)> ByRef rReturnedComObject As Object) As UInteger
End Function
'************************************************************************
<DllImport("ole32.dll")> _
Private Shared Function PropVariantClear(ByRef pvar As PropVariant) As Integer
End Function
Public Const DEVICE_STATE_ACTIVE As Integer = &H1
Public Const DEVICE_STATE_DISABLE As Integer = &H2
Public Const DEVICE_STATE_NOTPRESENT As Integer = &H4
Public Const DEVICE_STATE_UNPLUGGED As Integer = &H8
Public Const DEVICE_STATEMASK_ALL As Integer = &Hf
Public Shared PKEY_Device_FriendlyName As New PROPERTYKEY(&Ha45c254eUI, &Hdf1c, &H4efd, &H80, &H20, &H67, _
&Hd1, &H46, &Ha8, &H50, &He0, 14)
Public Shared PKEY_AudioEndpoint_FormFactor As New PROPERTYKEY(&H1da5d803, &Hd492, &H4edd, &H8c, &H23, &He0, _
&Hc0, &Hff, &Hee, &H7f, &He, 0)
End Class
Enum EndpointFormFactor
RemoteNetworkDevice = 0
Speakers = (RemoteNetworkDevice + 1)
LineLevel = (Speakers + 1)
Headphones = (LineLevel + 1)
Microphone = (Headphones + 1)
Headset = (Microphone + 1)
Handset = (Headset + 1)
UnknownDigitalPassthrough = (Handset + 1)
SPDIF = (UnknownDigitalPassthrough + 1)
DigitalAudioDisplayDevice = (SPDIF + 1)
UnknownFormFactor = (DigitalAudioDisplayDevice + 1)
EndpointFormFactor_enum_count = (UnknownFormFactor + 1)
End Enum
Enum EPcxConnectionType
eConnTypeUnknown = 0
eConnType3Point5mm
eConnTypeQuarter
eConnTypeAtapiInternal
eConnTypeRCA
eConnTypeOptical
eConnTypeOtherDigital
eConnTypeOtherAnalog
eConnTypeMultichannelAnalogDIN
eConnTypeXlrProfessional
eConnTypeRJ11Modem
eConnTypeCombination
End Enum
Enum EPcxGeoLocation
eGeoLocRear = &H1
eGeoLocFront
eGeoLocLeft
eGeoLocRight
eGeoLocTop
eGeoLocBottom
eGeoLocRearPanel
eGeoLocRiser
eGeoLocInsideMobileLid
eGeoLocDrivebay
eGeoLocHDMI
eGeoLocOutsideMobileLid
eGeoLocATAPI
eGeoLocNotApplicable
eGeoLocReserved6
EPcxGeoLocation_enum_count
End Enum
Public Enum EDataFlow
eRender
eCapture
eAll
EDataFlow_enum_count
End Enum
Public Enum ERole
eConsole
eMultimedia
eCommunications
ERole_enum_count
End Enum
Public Enum CLSCTX
CLSCTX_INPROC_SERVER = &H1
CLSCTX_INPROC_HANDLER = &H2
CLSCTX_LOCAL_SERVER = &H4
CLSCTX_REMOTE_SERVER = &H10
CLSCTX_SERVER = (CLSCTX_INPROC_SERVER Or CLSCTX_LOCAL_SERVER Or CLSCTX_REMOTE_SERVER)
CLSCTX_ALL = (CLSCTX_INPROC_HANDLER Or CLSCTX_SERVER)
End Enum
'Windows Core Audio API declarations
'http://www.java2s.com/Code/CSharp/Windows/SoundUtils.htm
<Guid("0BD7A1BE-7A1A-44DB-8397-CC5392387B5E"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IMMDeviceCollection
Function GetCount(ByRef pcDevices As UInteger) As Integer
Function Item(nDevice As UInteger, <Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppDevice As Object) As Integer
End Interface
<Guid("D666063F-1587-4E43-81F1-B948E807363F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IMMDevice
Function Activate(ByRef iid As Guid, dwClsCtx As UInteger, pActivationParams As IntPtr, <Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppInterface As Object) As Integer
Function OpenPropertyStore(stgmAccess As Integer, <Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppProperties As Object) As Integer
Function GetId(ByRef ppstrId As StringBuilder) As Integer
Function GetState(ByRef pdwState As Integer) As Integer
End Interface
<ComImport, Guid("BCDE0395-E52F-467C-8E3D-C4579291692E")> _
Class MMDeviceEnumerator
End Class
<Guid("A95664D2-9614-4F35-A746-DE8DB63617E6"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IMMDeviceEnumerator
Function EnumAudioEndpoints(dataFlow As EDataFlow, dwStateMask As Integer, <Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppDevices As Object) As Integer
Function GetDefaultAudioEndpoint(dataFlow As EDataFlow, role As ERole, <Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppEndpoint As Object) As Integer
Function GetDevice(pwstrId As String, ByRef ppDevice As IntPtr) As Integer
Function RegisterEndpointNotificationCallback(pClient As IntPtr) As Integer
Function UnregisterEndpointNotificationCallback(pClient As IntPtr) As Integer
End Interface
'*********** Property store *****************************
' https://blogs.msdn.microsoft.com/adamroot/2008/04/11/interop-with-propvariants-in-net/
<ComImport, Guid("886D8EEB-8CF2-4446-8D02-CDBA1DBDCF99"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Interface IPropertyStore
<MethodImpl(MethodImplOptions.InternalCall, MethodCodeType := MethodCodeType.Runtime)> _
Sub GetCount(<Out> ByRef cProps As UInteger)
<MethodImpl(MethodImplOptions.InternalCall, MethodCodeType := MethodCodeType.Runtime)> _
Sub GetAt(<[In]> iProp As UInteger, ByRef pkey As PROPERTYKEY)
<MethodImpl(MethodImplOptions.InternalCall, MethodCodeType := MethodCodeType.Runtime)> _
Function GetValue(<[In]> ByRef key As PROPERTYKEY, ByRef pv As PropVariant) As Integer
<MethodImpl(MethodImplOptions.InternalCall, MethodCodeType := MethodCodeType.Runtime)> _
Sub SetValue(<[In]> ByRef key As PROPERTYKEY, <[In]> ByRef pv As Object)
<MethodImpl(MethodImplOptions.InternalCall, MethodCodeType := MethodCodeType.Runtime)> _
Sub Commit()
End Interface
<StructLayout(LayoutKind.Sequential, Pack := 4)> _
Structure PROPERTYKEY
Public fmtid As Guid
Public pid As UInteger
Public Sub New(guid As Guid, propertyId As Integer)
Me.fmtid = guid
Me.pid = CUInt(propertyId)
End Sub
Public Sub New(formatId As String, propertyId As Integer)
Me.New(New Guid(formatId), propertyId)
End Sub
Public Sub New(a As UInteger, b As UInteger, c As UInteger, d As UInteger, e As UInteger, f As UInteger, _
g As UInteger, h As UInteger, i As UInteger, j As UInteger, k As UInteger, propertyId As Integer)
Me.New(New Guid(CUInt(a), CUShort(b), CUShort(c), CByte(d), CByte(e), CByte(f), _
CByte(g), CByte(h), CByte(i), CByte(j), CByte(k)), propertyId)
End Sub
End Structure
<StructLayout(LayoutKind.Sequential)> _
Public Structure PropVariant
Private vt As UShort
Private wReserved1 As UShort
Private wReserved2 As UShort
Private wReserved3 As UShort
Private p As IntPtr
Private p2 As Integer
Private Function GetDataBytes() As Byte()
Dim ret As Byte() = New Byte(IntPtr.Size + (4 - 1)) {}
If IntPtr.Size = 4 Then
BitConverter.GetBytes(p.ToInt32()).CopyTo(ret, 0)
ElseIf IntPtr.Size = 8 Then
BitConverter.GetBytes(p.ToInt64()).CopyTo(ret, 0)
End If
BitConverter.GetBytes(p2).CopyTo(ret, IntPtr.Size)
Return ret
End Function
Private ReadOnly Property cVal() As SByte
' CHAR cVal;
Get
Return CSByte(GetDataBytes()(0))
End Get
End Property
Private ReadOnly Property iVal() As Short
' SHORT iVal;
Get
Return BitConverter.ToInt16(GetDataBytes(), 0)
End Get
End Property
Private ReadOnly Property lVal() As Integer
' LONG lVal;
Get
Return BitConverter.ToInt32(GetDataBytes(), 0)
End Get
End Property
Private ReadOnly Property hVal() As Long
' LARGE_INTEGER hVal;
Get
Return BitConverter.ToInt64(GetDataBytes(), 0)
End Get
End Property
Private ReadOnly Property fltVal() As Single
' FLOAT fltVal;
Get
Return BitConverter.ToSingle(GetDataBytes(), 0)
End Get
End Property
Public ReadOnly Property Value() As Object
Get
Select Case CType(vt, VarEnum)
Case VarEnum.VT_I1
Return cVal
Case VarEnum.VT_I2
Return iVal
Case VarEnum.VT_I4, VarEnum.VT_INT
Return lVal
Case VarEnum.VT_UI4, VarEnum.VT_I8
Return hVal
Case VarEnum.VT_R4
Return fltVal
Case VarEnum.VT_FILETIME
Return DateTime.FromFileTime(hVal)
Case VarEnum.VT_BSTR
Return Marshal.PtrToStringBSTR(p)
Case VarEnum.VT_BLOB
Dim blobData As Byte() = New Byte(lVal - 1) {}
Dim pBlobData As IntPtr
If IntPtr.Size = 4 Then
pBlobData = New IntPtr(p2)
ElseIf IntPtr.Size = 8 Then
pBlobData = New IntPtr(BitConverter.ToInt64(GetDataBytes(), 4))
Else
Throw New NotSupportedException()
End If
Marshal.Copy(pBlobData, blobData, 0, lVal)
Return blobData
Case VarEnum.VT_LPSTR
Return Marshal.PtrToStringAnsi(p)
Case VarEnum.VT_LPWSTR
Return Marshal.PtrToStringUni(p)
Case VarEnum.VT_UNKNOWN
Return Marshal.GetObjectForIUnknown(p)
Case VarEnum.VT_DISPATCH
Return p
Case Else
Throw New NotSupportedException("0x" + vt.ToString("X4") + " type not supported")
End Select
End Get
End Property
End Structure
'*****************************************************
'Device Topology declarations
<Guid("2A07407E-6497-4A18-9787-32F79BD0D98F"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IDeviceTopology
Function GetConnectorCount(<Out> ByRef pConnectorCount As Integer) As Integer
Function GetConnector(nIndex As Integer, ByRef ppConnector As IConnector) As Integer
Function GetSubunitCount(<Out> ByRef pCount As Integer) As Integer
'ISubunit
Function GetSubunit(nIndex As Integer, ByRef ppSubunit As Object) As Integer
Function GetPartById(nId As Integer, ByRef ppPart As IPart) As Integer
Function GetDeviceId(<Out, MarshalAs(UnmanagedType.LPWStr)> ByRef ppwstrDeviceId As String) As Integer
'IPartsList
Function GetSignalPath(pIPartFrom As IPart, pIPartTo As IPart, bRejectMixedPaths As Boolean, ppParts As Object) As Integer
End Interface
<InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("9c2c4058-23f5-41de-877a-df3af236a09e")> _
Public Interface IConnector
Function [GetType](ByRef pType As Integer) As Integer
Function GetDataFlow(ByRef dataFlow As EDataFlow) As Integer
Function ConnectTo(<[In]> connector As IConnector) As Integer
Function Disconnect() As Integer
Function IsConnected(ByRef pbConnected As Boolean) As Integer
Function GetConnectedTo(<MarshalAs(UnmanagedType.[Interface])> ByRef ppConTo As Object) As Integer
Function GetConnectorIdConnectedTo(ByRef ppwstrConnectorId As String) As Integer
Function GetDeviceIdConnectedTo(ByRef ppwstrDeviceId As String) As Integer
End Interface
<Guid("AE2DE0E4-5BCA-4F2D-AA46-5D13F8FDB3A9"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)> _
Public Interface IPart
Function GetName(ByRef ppwstrName As StringBuilder) As Integer
Function GetLocalId(ByRef pnId As Integer) As Integer
Function GetGlobalId(ByRef ppwstrGlobalId As StringBuilder) As Integer
Function GetPartType(ByRef pPartType As Integer) As Integer
Function GetSubType(ByRef pSubType As Guid) As Integer
Function GetControlInterfaceCount(ByRef pCount As UInteger) As Integer
'IControlInterface
Function GetControlInterface(nIndex As Integer, ByRef ppFunction As Object) As Integer
'IPartsList[]
Function EnumPartsIncoming(ByRef ppParts As Object) As Integer
'IPartsList[]
Function EnumPartsOutgoing(ByRef ppParts As Object) As Integer
Function GetTopologyObject(<Out, MarshalAs(UnmanagedType.[Interface])> ByRef ppTopology As Object) As Integer
Function Activate(dwClsContext As UInteger, ByRef refiid As Guid, <MarshalAs(UnmanagedType.[Interface])> ByRef interfacePointer As Object) As Integer
'IControlChangeNotify
Function RegisterControlChangeCallback(ByRef riid As Guid, pNofity As Object) As Integer
'IControlChangeNotify
Function UnregisterControlChangeCallback(pNotify As Object) As Integer
End Interface
<ComVisible(False)> _
<ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("4509F757-2D46-4637-8E62-CE7DB944F57B")> _
Public Interface IKsJackDescription
Function GetJackCount(ByRef jacks As UInteger) As Integer
Function GetJackDescription(jack As UInteger, ByRef pDescription As KSJACK_DESCRIPTION) As Integer
End Interface
<StructLayout(LayoutKind.Sequential)> _
Public Structure KSJACK_DESCRIPTION
Public ChannelMapping As UInteger
Public Color As UInteger
Public ConnectionType As UInteger
Public GeoLocation As UInteger
Public GenLocation As UInteger
Public PortConnection As UInteger
Public IsConnected As UInteger
End Structure
End Namespace
Example how to get info about current default device's jack information
Imports System
Imports System.Collections.Generic
Imports System.Data
Imports System.Text
Imports System.Windows.Forms
Imports System.Runtime.InteropServices
Imports System.ComponentModel
Namespace com_test
Public Partial Class Form1
Inherits Form
'displays device
Private Function PrintDevice(dev As IMMDevice) As String
Dim propertyStore As IPropertyStore = Nothing
Dim pDeviceTopology As IDeviceTopology = Nothing
Dim pConnFrom As IConnector = Nothing
Dim pConnTo As IConnector = Nothing
Dim pPart As IPart = Nothing
Dim pJackDesc As IKsJackDescription = Nothing
Dim desc As New KSJACK_DESCRIPTION()
Dim res As New StringBuilder(300)
Dim o As Object = Nothing
Dim state As Integer = 0
Dim con_count As UInteger = 0
Try
'device name
'STGM_READ
dev.OpenPropertyStore(0, o)
propertyStore = TryCast(o, IPropertyStore)
Dim friendlyName As New PropVariant()
propertyStore.GetValue(Native.PKEY_Device_FriendlyName, friendlyName)
res.AppendLine(friendlyName.Value.ToString())
'form factor
Dim FormFactor As New PropVariant()
propertyStore.GetValue(Native.PKEY_AudioEndpoint_FormFactor, FormFactor)
Dim f As EndpointFormFactor = EndpointFormFactor.UnknownFormFactor
[Enum].TryParse(Of EndpointFormFactor)(FormFactor.Value.ToString(), f)
res.AppendLine("Form factor: " + f.ToString())
dev.GetState(state)
Dim str As String = ""
Select Case state
Case Native.DEVICE_STATE_DISABLE
str = ("Disabled")
Exit Select
Case Native.DEVICE_STATE_NOTPRESENT
str = ("Not present")
Exit Select
Case Native.DEVICE_STATE_UNPLUGGED
str = ("Unplugged")
Exit Select
End Select
If str <> "" Then
res.AppendLine(str)
End If
' DEVICE TOPOLOGY
Dim iidDeviceTopology As New Guid("2A07407E-6497-4A18-9787-32F79BD0D98F")
dev.Activate(iidDeviceTopology, CUInt(CLSCTX.CLSCTX_ALL), IntPtr.Zero, o)
pDeviceTopology = TryCast(o, IDeviceTopology)
pDeviceTopology.GetConnector(0, pConnFrom)
Try
o = Nothing
pConnFrom.GetConnectedTo(o)
pConnTo = TryCast(o, IConnector)
pPart = CType(pConnTo, IPart)
'QueryInterface
Dim iidKsJackDescription As New Guid("4509F757-2D46-4637-8E62-CE7DB944F57B")
pPart.Activate(CUInt(CLSCTX.CLSCTX_INPROC_SERVER), iidKsJackDescription, o)
pJackDesc = CType(o, IKsJackDescription)
If pJackDesc IsNot Nothing Then
con_count = 0
pJackDesc.GetJackCount(con_count)
If con_count > 0 Then
Dim sb As StringBuilder
'display jacks
For i As UInteger = 0 To con_count - 1
pJackDesc.GetJackDescription(i, desc)
sb = New StringBuilder(100)
Dim con_type As EPcxConnectionType = CType(desc.ConnectionType, EPcxConnectionType)
Dim loc As EPcxGeoLocation = CType(desc.GeoLocation, EPcxGeoLocation)
res.Append("* ")
Select Case con_type
Case EPcxConnectionType.eConnType3Point5mm
sb.Append("Jack 3.5 mm ")
Exit Select
Case EPcxConnectionType.eConnTypeAtapiInternal
sb.Append("ATAPI jack")
Exit Select
Case EPcxConnectionType.eConnTypeRCA
sb.Append("RCA jack")
Exit Select
Case EPcxConnectionType.eConnTypeQuarter
sb.Append("1/2 in. jack ")
Exit Select
Case EPcxConnectionType.eConnTypeOtherAnalog
sb.Append("Analog jack ")
Exit Select
Case EPcxConnectionType.eConnTypeOtherDigital
sb.Append("Digital jack ")
Exit Select
Case Else
sb.Append(con_type.ToString() + " ")
Exit Select
End Select
sb.Append("- " + loc.ToString())
'jack location
res.Append(sb.ToString())
If desc.IsConnected = 0 Then
res.AppendLine(": Disconnected")
Else
res.AppendLine(": Connected")
End If
'end for
Next
Else
res.AppendLine("* No jacks")
End If
Else
res.AppendLine("* Unable to get jacks")
End If
Catch ex As COMException
If CUInt(ex.HResult) = &H80070490UI Then
'E_NOTFOUND
res.AppendLine("Disconnected")
Else
res.AppendLine("COM error while getting jacks: " + ex.Message)
End If
Catch ex As Exception
res.AppendLine("Error while getting jacks: " + ex.Message)
End Try
Finally
'clean up resources
If dev IsNot Nothing Then
Marshal.ReleaseComObject(dev)
End If
If propertyStore IsNot Nothing Then
Marshal.ReleaseComObject(propertyStore)
End If
If pDeviceTopology IsNot Nothing Then
Marshal.ReleaseComObject(pDeviceTopology)
pDeviceTopology = Nothing
End If
If pConnFrom IsNot Nothing Then
Marshal.ReleaseComObject(pConnFrom)
pConnFrom = Nothing
End If
If pConnTo IsNot Nothing Then
Marshal.ReleaseComObject(pConnTo)
pConnTo = Nothing
End If
If pPart IsNot Nothing Then
Marshal.ReleaseComObject(pPart)
pPart = Nothing
End If
If pJackDesc IsNot Nothing Then
Marshal.ReleaseComObject(pJackDesc)
pJackDesc = Nothing
End If
End Try
Return res.ToString()
End Function
Public Sub New()
InitializeComponent()
End Sub
Private Sub button_Click(sender As Object, e As EventArgs)
Dim devenum As New MMDeviceEnumerator()
'Create enumerator
Dim deviceEnumerator As IMMDeviceEnumerator = CType(devenum, IMMDeviceEnumerator)
Dim defDevice As IMMDevice = Nothing
Dim propertyStore As IPropertyStore = Nothing
Try
Dim o As Object = Nothing
' * get default device *
deviceEnumerator.GetDefaultAudioEndpoint(EDataFlow.eRender, ERole.eConsole, o)
defDevice = TryCast(o, IMMDevice)
textBox1.Text = "Default sound device: " + Environment.NewLine + Environment.NewLine
textBox1.Text += PrintDevice(defDevice)
Catch ex As Exception
MessageBox.Show(ex.ToString())
Finally
'clean up resources
If devenum IsNot Nothing Then
Marshal.ReleaseComObject(devenum)
End If
If deviceEnumerator IsNot Nothing Then
Marshal.ReleaseComObject(deviceEnumerator)
End If
If defDevice IsNot Nothing Then
Marshal.ReleaseComObject(defDevice)
End If
If propertyStore IsNot Nothing Then
Marshal.ReleaseComObject(propertyStore)
End If
End Try
End Sub
End Class
End Namespace