vb.net code for volume control

hello vb.net coders.. i've been trying to control volume thru vb.net and i cannot see how to do that. I searched but all i could find was vb6 code. i know several of you are working with vb.net... is there any sample source code they can send me or post here for others to be able to use? thanx

i've got it at home... (at work right now). it's pretty straight forward. i'll post it tonight (around 6PM EST).

thnx :)

okay, the one i use is in c#. can't remember where I found it online since it took a **** load of googling. i didn't feel like writing all the marshalling stuff myself, but this is the best one i found. shouldn't be hard to convert it to Vb.net.

Code:

---

using System;
using System.Runtime.InteropServices;

namespace PhidgetTest
{
        public class AudioMixerHelper
        {
                public const int MMSYSERR_NOERROR = 0;
                public const int MAXPNAMELEN = 32;
                public const int MIXER_LONG_NAME_CHARS = 64;
                public const int MIXER_SHORT_NAME_CHARS = 16;
                public const int MIXER_GETLINEINFOF_COMPONENTTYPE = 0x3;
                public const int MIXER_GETCONTROLDETAILSF_VALUE = 0x0;
                public const int MIXER_GETLINECONTROLSF_ONEBYTYPE = 0x2;
                public const int MIXER_SETCONTROLDETAILSF_VALUE = 0x0;
                public const int MIXERLINE_COMPONENTTYPE_DST_FIRST = 0x0;
                public const int MIXERLINE_COMPONENTTYPE_SRC_FIRST = 0x1000;
                public const int MIXERLINE_COMPONENTTYPE_DST_SPEAKERS =
                        (MIXERLINE_COMPONENTTYPE_DST_FIRST + 4);
                public const int MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE =
                        (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 3);
                public const int MIXERLINE_COMPONENTTYPE_SRC_LINE =
                        (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 2);
                public const int MIXERCONTROL_CT_CLASS_FADER = 0x50000000;
                public const int MIXERCONTROL_CT_UNITS_UNSIGNED = 0x30000;
                public const int MIXERCONTROL_CONTROLTYPE_FADER =
                        (MIXERCONTROL_CT_CLASS_FADER | MIXERCONTROL_CT_UNITS_UNSIGNED);
                public const int MIXERCONTROL_CONTROLTYPE_VOLUME =
                        (MIXERCONTROL_CONTROLTYPE_FADER + 1);

                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerClose (int hmx);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetControlDetailsA (int hmxobj,ref
                        MIXERCONTROLDETAILS pmxcd , int fdwDetails);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetDevCapsA(int uMxId, MIXERCAPS
                        pmxcaps, int cbmxcaps);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetID (int hmxobj, int pumxID, int
                        fdwId);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetLineControlsA (int hmxobj,ref
                        MIXERLINECONTROLS pmxlc, int fdwControls);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetLineInfoA (int hmxobj,ref
                        MIXERLINE pmxl , int fdwInfo);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerGetNumDevs();
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerMessage(int hmx , int uMsg , int
                        dwParam1 , int dwParam2);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerOpen (out int phmx , int uMxId ,
                        int dwCallback , int dwInstance , int fdwOpen);
                [DllImport("winmm.dll", CharSet=CharSet.Ansi)]
                private static extern int mixerSetControlDetails(int hmxobj ,ref
                        MIXERCONTROLDETAILS pmxcd , int fdwDetails);

                public struct MIXERCAPS
                {
                        public int wMid;
                        public int wPid;
                        public int vDriverVersion;
                        [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MAXPNAMELEN)]
                        public string szPname;
                        public int fdwSupport;
                        public int cDestinations;
                }

                public struct MIXERCONTROL
                {
                        public int cbStruct;
                        public int dwControlID;
                        public int dwControlType;
                        public int fdwControl;
                        public int cMultipleItems;
                        [MarshalAs( UnmanagedType.ByValTStr,
                                SizeConst=MIXER_SHORT_NAME_CHARS)]
                        public string szShortName ;
                        [MarshalAs( UnmanagedType.ByValTStr,
                                SizeConst=MIXER_LONG_NAME_CHARS)]
                        public string szName;
                        public int lMinimum;
                        public int lMaximum;
                        [MarshalAs(UnmanagedType.U4, SizeConst=10)]
                        public int reserved;
                }

                public struct MIXERCONTROLDETAILS
                {
                        public int cbStruct;
                        public int dwControlID;
                        public int cChannels;
                        public int item;
                        public int cbDetails;
                        public IntPtr paDetails;
                }

                public struct MIXERCONTROLDETAILS_UNSIGNED
                {
                        public int dwValue;
                }

                public struct MIXERLINE
                {
                        public int cbStruct;
                        public int dwDestination;
                        public int dwSource;
                        public int dwLineID;
                        public int fdwLine;
                        public int dwUser;
                        public int dwComponentType;
                        public int cChannels;
                        public int cConnections;
                        public int cControls;
                        [MarshalAs(UnmanagedType.ByValTStr,
                                SizeConst=MIXER_SHORT_NAME_CHARS)]
                        public string szShortName;
                        [MarshalAs(UnmanagedType.ByValTStr,
                                SizeConst=MIXER_LONG_NAME_CHARS )]
                        public string szName;
                        public int dwType;
                        public int dwDeviceID;
                        public int wMid;
                        public int wPid;
                        public int vDriverVersion ;
                        [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MAXPNAMELEN)]
                        public string szPname ;
                }

                public struct MIXERLINECONTROLS
                {
                        public int cbStruct;
                        public int dwLineID;

                        public int dwControl;
                        public int cControls;
                        public int cbmxctrl;
                        public IntPtr pamxctrl;
                }

                private static bool GetVolumeControl(int hmixer, int componentType,
                        int ctrlType, out MIXERCONTROL mxc, out int vCurrentVol)
                {
                        // This function attempts to obtain a mixer control.
                        // Returns True if successful.
                        MIXERLINECONTROLS mxlc = new MIXERLINECONTROLS();
                        MIXERLINE mxl = new MIXERLINE();
                        MIXERCONTROLDETAILS pmxcd = new MIXERCONTROLDETAILS();
                        MIXERCONTROLDETAILS_UNSIGNED du = new
                                MIXERCONTROLDETAILS_UNSIGNED();
                        mxc = new MIXERCONTROL();
                        int rc;
                        bool retValue;
                        vCurrentVol = -1;

                        mxl.cbStruct = Marshal.SizeOf(mxl);
                        mxl.dwComponentType = componentType;

                        rc = mixerGetLineInfoA(hmixer,ref mxl,
                                MIXER_GETLINEINFOF_COMPONENTTYPE );

                        if(MMSYSERR_NOERROR == rc)
                        {
                                int sizeofMIXERCONTROL = 152;
                                int ctrl = Marshal.SizeOf(typeof(MIXERCONTROL));
                                mxlc.pamxctrl = Marshal.AllocCoTaskMem(sizeofMIXERCONTROL);
                                mxlc.cbStruct = Marshal.SizeOf(mxlc);
                                mxlc.dwLineID = mxl.dwLineID;
                                mxlc.dwControl = ctrlType;
                                mxlc.cControls = 1;
                                mxlc.cbmxctrl = sizeofMIXERCONTROL;

                                // Allocate a buffer for the control
                                mxc.cbStruct = sizeofMIXERCONTROL;

                                // Get the control
                                rc = mixerGetLineControlsA(hmixer,ref mxlc,
                                        MIXER_GETLINECONTROLSF_ONEBYTYPE);

                                if(MMSYSERR_NOERROR == rc)
                                {
                                        retValue = true;

                                        // Copy the control into the destination structure
                                        mxc = (MIXERCONTROL)Marshal.PtrToStructure(
                                                mxlc.pamxctrl,typeof(MIXERCONTROL));
                                }
                                else
                                {
                                        retValue = false;
                                }
                                int sizeofMIXERCONTROLDETAILS =
                                        Marshal.SizeOf(typeof(MIXERCONTROLDETAILS));
                                int sizeofMIXERCONTROLDETAILS_UNSIGNED =
                                        Marshal.SizeOf(typeof(MIXERCONTROLDETAILS_UNSIGNED));
                                pmxcd.cbStruct = sizeofMIXERCONTROLDETAILS;
                                pmxcd.dwControlID = mxc.dwControlID;
                                pmxcd.paDetails =

                                        Marshal.AllocCoTaskMem(sizeofMIXERCONTROLDETAILS_UNSIGNED) ;
                                pmxcd.cChannels = 1;
                                pmxcd.item = 0;
                                pmxcd.cbDetails = sizeofMIXERCONTROLDETAILS_UNSIGNED;

                                rc = mixerGetControlDetailsA(hmixer,ref pmxcd,
                                        MIXER_GETCONTROLDETAILSF_VALUE);

                                du = (MIXERCONTROLDETAILS_UNSIGNED)Marshal.PtrToStructure(
                                        pmxcd.paDetails, typeof(MIXERCONTROLDETAILS_UNSIGNED));

                                vCurrentVol = du.dwValue;

                                return retValue;
                        }

                        retValue = false;
                        return retValue;
                }

                private static bool SetVolumeControl(int hmixer, MIXERCONTROL mxc,
                        int volume)
                {
                        // This function sets the value for a volume control.
                        // Returns True if successful

                        bool retValue;
                        int rc;
                        MIXERCONTROLDETAILS mxcd = new MIXERCONTROLDETAILS();
                        MIXERCONTROLDETAILS_UNSIGNED vol = new
                                MIXERCONTROLDETAILS_UNSIGNED();

                        mxcd.item = 0;
                        mxcd.dwControlID = mxc.dwControlID;
                        mxcd.cbStruct = Marshal.SizeOf(mxcd);
                        mxcd.cbDetails = Marshal.SizeOf(vol);

                        // Allocate a buffer for the control value buffer
                        mxcd.cChannels = 1;
                        vol.dwValue = volume;

                        // Copy the data into the control value buffer
                        mxcd.paDetails = Marshal.AllocCoTaskMem(Marshal.SizeOf(
                                typeof(MIXERCONTROLDETAILS_UNSIGNED)));
                        Marshal.StructureToPtr(vol, mxcd.paDetails,false);

                        // Set the control value
                        rc = mixerSetControlDetails(hmixer,ref mxcd,
                                MIXER_SETCONTROLDETAILSF_VALUE);

                        if(MMSYSERR_NOERROR == rc)
                        {
                                retValue = true;
                        }
                        else
                        {
                                retValue = false;
                        } return retValue;
                }

                public static int GetVolume()
                {
                        int mixer;
                        MIXERCONTROL volCtrl = new MIXERCONTROL();
                        int currentVol;
                        mixerOpen(out mixer,0 ,0 ,0, 0);
                        int type = MIXERCONTROL_CONTROLTYPE_VOLUME;
                        GetVolumeControl(mixer,
                                MIXERLINE_COMPONENTTYPE_DST_SPEAKERS,type,out volCtrl, out
                                currentVol);
                        mixerClose(mixer);

                        return currentVol;
                }

                public static void SetVolume(int vVolume)
                {
                        int mixer;
                        MIXERCONTROL volCtrl = new MIXERCONTROL();
                        int currentVol;
                        mixerOpen(out mixer,0 ,0 ,0, 0);
                        int type = MIXERCONTROL_CONTROLTYPE_VOLUME;
                        GetVolumeControl(mixer,
                                MIXERLINE_COMPONENTTYPE_DST_SPEAKERS,type,out volCtrl, out
                                currentVol);
                        if(vVolume > volCtrl.lMaximum) vVolume = volCtrl.lMaximum;
                        if(vVolume < volCtrl.lMinimum) vVolume = volCtrl.lMinimum;
                        SetVolumeControl(mixer, volCtrl, vVolume);
                        GetVolumeControl(mixer,
                                MIXERLINE_COMPONENTTYPE_DST_SPEAKERS,type,out volCtrl, out
                                currentVol);
                        if(vVolume != currentVol)
                        {
                                throw new Exception("Cannot Set Volume");
                        }
                        mixerClose(mixer);
                }
        }
}

---

Here is a neat site that translates c# into VB. Its not 100% but its makes it a lot easier... http://authors.aspalliance.com/aldot...translate.aspx

This is great I was just going to ask the same damn question... I was actually think about using directX 8.0 for mixer controls..

This definalty is tough to impliment into VB.net

I used that C#->VB.NET translator, but had to make a few corrections:

Code:

---

Imports System
Imports System.Runtime.InteropServices

Public Class AudioMixerHelper
    Public Const MMSYSERR_NOERROR As Integer = 0
    Public Const MAXPNAMELEN As Integer = 32
    Public Const MIXER_LONG_NAME_CHARS As Integer = 64
    Public Const MIXER_SHORT_NAME_CHARS As Integer = 16
    Public Const MIXER_GETLINEINFOF_COMPONENTTYPE As Integer = &H3
    Public Const MIXER_GETCONTROLDETAILSF_VALUE As Integer = &H0
    Public Const MIXER_GETLINECONTROLSF_ONEBYTYPE As Integer = &H2
    Public Const MIXER_SETCONTROLDETAILSF_VALUE As Integer = &H0
    Public Const MIXERLINE_COMPONENTTYPE_DST_FIRST As Integer = &H0
    Public Const MIXERLINE_COMPONENTTYPE_SRC_FIRST As Integer = &H1000
    Public Const MIXERLINE_COMPONENTTYPE_DST_SPEAKERS As Integer = MIXERLINE_COMPONENTTYPE_DST_FIRST + 4
    Public Const MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE As Integer = MIXERLINE_COMPONENTTYPE_SRC_FIRST + 3
    Public Const MIXERLINE_COMPONENTTYPE_SRC_LINE As Integer = MIXERLINE_COMPONENTTYPE_SRC_FIRST + 2
    Public Const MIXERCONTROL_CT_CLASS_FADER As Integer = &H50000000
    Public Const MIXERCONTROL_CT_UNITS_UNSIGNED As Integer = &H30000
    Public Const MIXERCONTROL_CONTROLTYPE_FADER As Integer = MIXERCONTROL_CT_CLASS_FADER Or MIXERCONTROL_CT_UNITS_UNSIGNED
    Public Const MIXERCONTROL_CONTROLTYPE_VOLUME As Integer = MIXERCONTROL_CONTROLTYPE_FADER + 1

    Private Declare Ansi Function mixerClose Lib "winmm.dll" (ByVal hmx As Integer) As Integer

    Private Declare Ansi Function mixerGetControlDetailsA Lib "winmm.dll" (ByVal hmxobj As Integer, ByRef pmxcd As MIXERCONTROLDETAILS, ByVal fdwDetails As Integer) As Integer

    Private Declare Ansi Function mixerGetDevCapsA Lib "winmm.dll" (ByVal uMxId As Integer, ByVal pmxcaps As MIXERCAPS, ByVal cbmxcaps As Integer) As Integer

    Private Declare Ansi Function mixerGetID Lib "winmm.dll" (ByVal hmxobj As Integer, ByVal pumxID As Integer, ByVal fdwId As Integer) As Integer

    Private Declare Ansi Function mixerGetLineControlsA Lib "winmm.dll" (ByVal hmxobj As Integer, ByRef pmxlc As MIXERLINECONTROLS, ByVal fdwControls As Integer) As Integer

    Private Declare Ansi Function mixerGetLineInfoA Lib "winmm.dll" (ByVal hmxobj As Integer, ByRef pmxl As MIXERLINE, ByVal fdwInfo As Integer) As Integer

    Private Declare Ansi Function mixerGetNumDevs Lib "winmm.dll" () As Integer

    Private Declare Ansi Function mixerMessage Lib "winmm.dll" (ByVal hmx As Integer, ByVal uMsg As Integer, ByVal dwParam1 As Integer, ByVal dwParam2 As Integer) As Integer

    Private Declare Ansi Function mixerOpen Lib "winmm.dll" (ByRef phmx As Integer, ByVal uMxId As Integer, ByVal dwCallback As Integer, ByVal dwInstance As Integer, ByVal fdwOpen As Integer) As Integer

    Private Declare Ansi Function mixerSetControlDetails Lib "winmm.dll" (ByVal hmxobj As Integer, ByRef pmxcd As MIXERCONTROLDETAILS, ByVal fdwDetails As Integer) As Integer

    Public Structure MIXERCAPS
        Public wMid As Integer
        Public wPid As Integer
        Public vDriverVersion As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MAXPNAMELEN)> Public szPname As String
        Public fdwSupport As Integer
        Public cDestinations As Integer
    End Structure 'MIXERCAPS
      _

    Public Structure MIXERCONTROL
        Public cbStruct As Integer
        Public dwControlID As Integer
        Public dwControlType As Integer
        Public fdwControl As Integer
        Public cMultipleItems As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_SHORT_NAME_CHARS)> Public szShortName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_LONG_NAME_CHARS)> Public szName As String
        Public lMinimum As Integer
        Public lMaximum As Integer
        <MarshalAs(UnmanagedType.U4, SizeConst:=10)> Public reserved As Integer
    End Structure 'MIXERCONTROL
      _

    Public Structure MIXERCONTROLDETAILS
        Public cbStruct As Integer
        Public dwControlID As Integer
        Public cChannels As Integer
        Public item As Integer
        Public cbDetails As Integer
        Public paDetails As IntPtr
    End Structure 'MIXERCONTROLDETAILS
      _

    Public Structure MIXERCONTROLDETAILS_UNSIGNED
        Public dwValue As Integer
    End Structure 'MIXERCONTROLDETAILS_UNSIGNED
      _

    Public Structure MIXERLINE
        Public cbStruct As Integer
        Public dwDestination As Integer
        Public dwSource As Integer
        Public dwLineID As Integer
        Public fdwLine As Integer
        Public dwUser As Integer
        Public dwComponentType As Integer
        Public cChannels As Integer
        Public cConnections As Integer
        Public cControls As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_SHORT_NAME_CHARS)> Public szShortName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_LONG_NAME_CHARS)> Public szName As String
        Public dwType As Integer
        Public dwDeviceID As Integer
        Public wMid As Integer
        Public wPid As Integer
        Public vDriverVersion As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MAXPNAMELEN)> Public szPname As String
    End Structure 'MIXERLINE
      _

    Public Structure MIXERLINECONTROLS
        Public cbStruct As Integer
        Public dwLineID As Integer

        Public dwControl As Integer
        Public cControls As Integer
        Public cbmxctrl As Integer
        Public pamxctrl As IntPtr
    End Structure 'MIXERLINECONTROLS


    Private Shared Function GetVolumeControl(ByVal hmixer As Integer, ByVal componentType As Integer, ByVal ctrlType As Integer, ByRef mxc As MIXERCONTROL, ByRef vCurrentVol As Integer) As Boolean
        ' This function attempts to obtain a mixer control.
        ' Returns True if successful.
        Dim mxlc As New MIXERLINECONTROLS
        Dim mxl As New MIXERLINE
        Dim pmxcd As New MIXERCONTROLDETAILS
        Dim du As New MIXERCONTROLDETAILS_UNSIGNED
        mxc = New MIXERCONTROL
        Dim rc As Integer
        Dim retValue As Boolean
        vCurrentVol = -1

        mxl.cbStruct = Marshal.SizeOf(mxl)
        mxl.dwComponentType = componentType

        rc = mixerGetLineInfoA(hmixer, mxl, MIXER_GETLINEINFOF_COMPONENTTYPE)

        If MMSYSERR_NOERROR = rc Then
            Dim sizeofMIXERCONTROL As Integer = 152
            Dim ctrl As Integer = Marshal.SizeOf(GetType(MIXERCONTROL))
            mxlc.pamxctrl = Marshal.AllocCoTaskMem(sizeofMIXERCONTROL)
            mxlc.cbStruct = Marshal.SizeOf(mxlc)
            mxlc.dwLineID = mxl.dwLineID
            mxlc.dwControl = ctrlType
            mxlc.cControls = 1
            mxlc.cbmxctrl = sizeofMIXERCONTROL

            ' Allocate a buffer for the control
            mxc.cbStruct = sizeofMIXERCONTROL

            ' Get the control
            rc = mixerGetLineControlsA(hmixer, mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE)

            If MMSYSERR_NOERROR = rc Then
                retValue = True

                ' Copy the control into the destination structure
                mxc = CType(Marshal.PtrToStructure(mxlc.pamxctrl, GetType(MIXERCONTROL)), MIXERCONTROL)
            Else
                retValue = False
            End If
            Dim sizeofMIXERCONTROLDETAILS As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS))
            Dim sizeofMIXERCONTROLDETAILS_UNSIGNED As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED))
            pmxcd.cbStruct = sizeofMIXERCONTROLDETAILS
            pmxcd.dwControlID = mxc.dwControlID
            pmxcd.paDetails = Marshal.AllocCoTaskMem(sizeofMIXERCONTROLDETAILS_UNSIGNED)
            pmxcd.cChannels = 1
            pmxcd.item = 0
            pmxcd.cbDetails = sizeofMIXERCONTROLDETAILS_UNSIGNED

            rc = mixerGetControlDetailsA(hmixer, pmxcd, MIXER_GETCONTROLDETAILSF_VALUE)

            du = Marshal.PtrToStructure(pmxcd.paDetails, GetType(MIXERCONTROLDETAILS_UNSIGNED))

            vCurrentVol = du.dwValue

            Return retValue
        End If

        retValue = False
        Return retValue
    End Function 'GetVolumeControl


    Private Shared Function SetVolumeControl(ByVal hmixer As Integer, ByVal mxc As MIXERCONTROL, ByVal volume As Integer) As Boolean
        ' This function sets the value for a volume control.
        ' Returns True if successful
        Dim retValue As Boolean
        Dim rc As Integer
        Dim mxcd As New MIXERCONTROLDETAILS
        Dim vol As New MIXERCONTROLDETAILS_UNSIGNED

        mxcd.item = 0
        mxcd.dwControlID = mxc.dwControlID
        mxcd.cbStruct = Marshal.SizeOf(mxcd)
        mxcd.cbDetails = Marshal.SizeOf(vol)

        ' Allocate a buffer for the control value buffer
        mxcd.cChannels = 1
        vol.dwValue = volume

        ' Copy the data into the control value buffer
        mxcd.paDetails = Marshal.AllocCoTaskMem(Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED)))
        Marshal.StructureToPtr(vol, mxcd.paDetails, False)

        ' Set the control value
        rc = mixerSetControlDetails(hmixer, mxcd, MIXER_SETCONTROLDETAILSF_VALUE)

        If MMSYSERR_NOERROR = rc Then
            retValue = True
        Else
            retValue = False
        End If
        Return retValue
    End Function 'SetVolumeControl

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continued because forums complained text was too long...

Code:

---

    Public Shared Function GetVolume() As Integer
        Dim mixer As Integer
        Dim volCtrl As New MIXERCONTROL
        Dim currentVol As Integer
        mixerOpen(mixer, 0, 0, 0, 0)
        Dim type As Integer = MIXERCONTROL_CONTROLTYPE_VOLUME
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        mixerClose(mixer)

        Return currentVol
    End Function 'GetVolume


    Public Shared Sub SetVolume(ByVal vVolume As Integer)
        Dim mixer As Integer
        Dim volCtrl As New MIXERCONTROL
        Dim currentVol As Integer
        mixerOpen(mixer, 0, 0, 0, 0)
        Dim type As Integer = MIXERCONTROL_CONTROLTYPE_VOLUME
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        If vVolume > volCtrl.lMaximum Then
            vVolume = volCtrl.lMaximum
        End If
        If vVolume < volCtrl.lMinimum Then
            vVolume = volCtrl.lMinimum
        End If
        SetVolumeControl(mixer, volCtrl, vVolume)
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        If vVolume <> currentVol Then
            Throw New Exception("Cannot Set Volume")
        End If
        mixerClose(mixer)
    End Sub 'SetVolume
End Class 'AudioMixerHelper

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Sorry, but me English is not very good....

I want to make a program to set the balance control to center always. Could I have it with this code?

Somebody has compiled it?
Thank you.

Greetings....