/// <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 (IsControlBoolean(mc.dwControlType))
{
return(new BooleanMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
if (IsControlSigned(mc.dwControlType))
{
return(new SignedMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
if (IsControlUnsigned(mc.dwControlType))
{
return(new UnsignedMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
if (IsControlListText(mc.dwControlType))
{
return(new ListTextMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
if (IsControlCustom(mc.dwControlType))
{
return(new CustomMixerControl(mc, mixerHandle, mixerFlags, nChannels));
}
throw new ApplicationException(String.Format("Unknown mixer control type {0}", mc.dwControlType));
}
/// <summary>
/// Gets the control details
/// </summary>
protected void GetControlDetails()
{
mixerControlDetails.cbStruct = Marshal.SizeOf(mixerControlDetails);
mixerControlDetails.dwControlID = mixerControl.dwControlID;
if (IsCustom)
{
mixerControlDetails.cChannels = 0;
}
else if ((mixerControl.fdwControl & MixerInterop.MIXERCONTROL_CONTROLF_UNIFORM) != 0)
{
mixerControlDetails.cChannels = 1;
}
else
{
mixerControlDetails.cChannels = nChannels;
}
if ((mixerControl.fdwControl & MixerInterop.MIXERCONTROL_CONTROLF_MULTIPLE) != 0)
{
mixerControlDetails.hwndOwner = (IntPtr)mixerControl.cMultipleItems;
}
else if (IsCustom)
{
mixerControlDetails.hwndOwner = IntPtr.Zero; // TODO: special cases
}
else
{
mixerControlDetails.hwndOwner = IntPtr.Zero;
}
if (IsBoolean)
{
mixerControlDetails.cbDetails = Marshal.SizeOf(new MixerInterop.MIXERCONTROLDETAILS_BOOLEAN());
}
else if (IsListText)
{
mixerControlDetails.cbDetails = Marshal.SizeOf(new MixerInterop.MIXERCONTROLDETAILS_LISTTEXT());
}
else if (IsSigned)
{
mixerControlDetails.cbDetails = Marshal.SizeOf(new MixerInterop.MIXERCONTROLDETAILS_SIGNED());
}
else if (IsUnsigned)
{
mixerControlDetails.cbDetails = Marshal.SizeOf(new MixerInterop.MIXERCONTROLDETAILS_UNSIGNED());
}
else
{ // must be custom
mixerControlDetails.cbDetails = mixerControl.Metrics.customData;
}
// from the structs sample in MSDN (see MyPerson2)
IntPtr buffer = Marshal.AllocCoTaskMem(mixerControlDetails.cbDetails * mixerControlDetails.cChannels);
// To copy stuff in:
// Marshal.StructureToPtr( theStruct, buffer, false );
mixerControlDetails.paDetails = buffer;
MmResult err = MixerInterop.mixerGetControlDetails(mixerHandle, ref mixerControlDetails, MixerFlags.Value | mixerHandleType);
// let the derived classes get the details before we free the handle
if (err == MmResult.NoError)
{
GetDetails(mixerControlDetails.paDetails);
}
Marshal.FreeCoTaskMem(buffer);
if (err != MmResult.NoError)
{
throw new MmException(err, "mixerGetControlDetails");
}
}