/// <summary>
/// Gets a specified Mixer Control
/// </summary>
/// <param name="mixerHandle">Mixer Handle</param>
/// <param name="nLineID">Line ID</param>
/// <param name="controlId">Control ID</param>
/// <param name="nChannels">Number of Channels</param>
/// <param name="mixerFlags">Flags to use (indicates the meaning of mixerHandle)</param>
/// <returns></returns>
public static MixerControl GetMixerControl(IntPtr mixerHandle, int nLineID, int controlId, int nChannels,
MixerFlags mixerFlags)
{
MixerInterop.MIXERLINECONTROLS mlc = new MixerInterop.MIXERLINECONTROLS();
MixerInterop.MIXERCONTROL mc = new MixerInterop.MIXERCONTROL();
// set up the pointer to a structure
IntPtr pMixerControl = Marshal.AllocCoTaskMem(Marshal.SizeOf(mc));
//Marshal.StructureToPtr(mc, pMixerControl, false);
mlc.cbStruct = Marshal.SizeOf(mlc);
mlc.cControls = 1;
mlc.dwControlID = controlId;
mlc.cbmxctrl = Marshal.SizeOf(mc);
mlc.pamxctrl = pMixerControl;
mlc.dwLineID = nLineID;
MmResult err = MixerInterop.mixerGetLineControls(mixerHandle, ref mlc, MixerFlags.OneById | mixerFlags);
if (err != MmResult.NoError)
{
Marshal.FreeCoTaskMem(pMixerControl);
throw new MmException(err, "mixerGetLineControls");
}
// retrieve the structure from the pointer
mc = (MixerInterop.MIXERCONTROL)Marshal.PtrToStructure(mlc.pamxctrl, typeof(MixerInterop.MIXERCONTROL));
Marshal.FreeCoTaskMem(pMixerControl);
if (MixerControl.IsControlBoolean(mc.dwControlType))
{
return(new BooleanMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
else if (MixerControl.IsControlSigned(mc.dwControlType))
{
return(new SignedMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
else if (MixerControl.IsControlUnsigned(mc.dwControlType))
{
return(new UnsignedMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
else if (MixerControl.IsControlListText(mc.dwControlType))
{
return(new ListTextMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
else if (MixerControl.IsControlCustom(mc.dwControlType))
{
return(new CustomMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
else
{
throw new InvalidOperationException(String.Format("Unknown mixer control type {0}", mc.dwControlType));
}
}
/// <summary>
/// Gets all the mixer controls
/// </summary>
/// <param name="mixerHandle">Mixer Handle</param>
/// <param name="mixerLine">Mixer Line</param>
/// <param name="mixerHandleType">Mixer Handle Type</param>
/// <returns></returns>
public static IList <MixerControl> GetMixerControls(IntPtr mixerHandle, MixerLine mixerLine,
MixerFlags mixerHandleType)
{
var controls = new List <MixerControl>();
if (mixerLine.ControlsCount > 0)
{
int mixerControlSize = Marshal.SizeOf(typeof(MixerInterop.MIXERCONTROL));
var mlc = new MixerInterop.MIXERLINECONTROLS();
IntPtr pmc = Marshal.AllocHGlobal(mixerControlSize * mixerLine.ControlsCount);
mlc.cbStruct = Marshal.SizeOf(mlc);
mlc.dwLineID = mixerLine.LineId;
mlc.cControls = mixerLine.ControlsCount;
mlc.pamxctrl = pmc;
mlc.cbmxctrl = Marshal.SizeOf(typeof(MixerInterop.MIXERCONTROL));
try
{
MmResult err = MixerInterop.mixerGetLineControls(mixerHandle, ref mlc, MixerFlags.All | mixerHandleType);
if (err != MmResult.NoError)
{
throw new MmException(err, "mixerGetLineControls");
}
for (int i = 0; i < mlc.cControls; i++)
{
Int64 address = pmc.ToInt64() + mixerControlSize * i;
var mc = (MixerInterop.MIXERCONTROL)
Marshal.PtrToStructure((IntPtr)address, typeof(MixerInterop.MIXERCONTROL));
var mixerControl = GetMixerControl(mixerHandle, mixerLine.LineId, mc.dwControlID, mixerLine.Channels,
mixerHandleType);
controls.Add(mixerControl);
}
}
finally
{
Marshal.FreeHGlobal(pmc);
}
}
return(controls);
}