using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Media;
using System.Runtime.InteropServices;
namespace WindowsFormsApplication1
{
public partial class Form1 : Form
{
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 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;
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 =
int sizeofMIXERCONTROLDETAILS_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 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 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);
}
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show( this.GetVolume().ToString());
//set the master volume
this.SetVolume(1000);
//Display the new volume
MessageBox.Show(this.GetVolume().ToString());
}
}
}