/// <summary> /// method for retrieving the current volume from the system /// </summary> /// <returns>int value</returns> public static int GetVolume() { //method level variables int currVolume; int mixerControl; //create a new volume control VolumeStructs.Mixer mixer = new VolumeStructs.Mixer(); //open the mixer PCWin32.mixerOpen(out mixerControl, 0, 0, 0, 0); //set the type to volume control type int type = VolumeConstants.MIXERCONTROL_CONTROLTYPE_VOLUME; //get the mixer control and get the current volume level GetMixer(mixerControl, VolumeConstants.MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, out mixer, out currVolume); //close the mixer control since we are now done with it PCWin32.mixerClose(mixerControl); //return the current volume to the calling method return currVolume; }
/// <summary> /// method for setting the volume to a specific level /// </summary> /// <param name="volumeLevel">volume level we wish to set volume to</param> public static void SetVolume(int volumeLevel) { try { //method level variables int currVolume; int mixerControl; //create a new volume control VolumeStructs.Mixer volumeControl = new VolumeStructs.Mixer(); //open the mixer control PCWin32.mixerOpen(out mixerControl, 0, 0, 0, 0); //set the type to volume control type int controlType = VolumeConstants.MIXERCONTROL_CONTROLTYPE_VOLUME; //get the current mixer control and get the current volume GetMixer(mixerControl, VolumeConstants.MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, controlType, out volumeControl, out currVolume); //now check the volume level. If the volume level //is greater than the max then set the volume to //the max level. If it's less than the minimum level //then set it to the minimun level if (volumeLevel > volumeControl.lMaximum) { volumeLevel = volumeControl.lMaximum; } else if (volumeLevel < volumeControl.lMinimum) { volumeLevel = volumeControl.lMinimum; } //set the volume SetMixer(mixerControl, volumeControl, volumeLevel); //now re-get the mixer control GetMixer(mixerControl, VolumeConstants.MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, controlType, out volumeControl, out currVolume); //make sure the volume level is equal to the current volume if (volumeLevel != currVolume) { throw new Exception("Cannot Set Volume"); } //close the mixer control as we are finished with it PCWin32.mixerClose(mixerControl); } catch (Exception ex) { MessageBox.Show(ex.Message); } }
/// <summary> /// method to retrieve a mixer control /// </summary> /// <param name="i"></param> /// <param name="type"></param> /// <param name="ctrlType"></param> /// <param name="mixerControl"></param> /// <param name="currVolume"></param> /// <returns></returns> private static bool GetMixer(int i, int type, int ctrlType, out VolumeStructs.Mixer mixerControl, out int currVolume) { //create our method level variables int details; bool bReturn; currVolume = -1; //create our struct objects VolumeStructs.LineControls lineControls = new VolumeStructs.LineControls(); VolumeStructs.MixerLine line = new VolumeStructs.MixerLine(); VolumeStructs.MixerDetails mcDetails = new VolumeStructs.MixerDetails(); VolumeStructs.UnsignedMixerDetails detailsUnsigned = new VolumeStructs.UnsignedMixerDetails(); //create a new mixer control mixerControl = new VolumeStructs.Mixer(); //set the properties of out mixerline object line.cbStruct = Marshal.SizeOf(line); line.dwComponentType = type; //get the line info and assign it to our details variable details = PCWin32.mixerGetLineInfoA(i, ref line, VolumeConstants.MIXER_GETLINEINFOF_COMPONENTTYPE); //make sure we didnt receive any errors if (VolumeConstants.MMSYSERR_NOERROR == details) { int mcSize = 152; //get the size of the unmanaged type int control = Marshal.SizeOf(typeof(VolumeStructs.Mixer)); //allocate a block of memory lineControls.pamxctrl = Marshal.AllocCoTaskMem(mcSize); //get the size of the line controls lineControls.cbStruct = Marshal.SizeOf(lineControls); //set properties for our mixer control lineControls.dwLineID = line.dwLineID; lineControls.dwControl = ctrlType; lineControls.cControls = 1; lineControls.cbmxctrl = mcSize; // Allocate a buffer for the control mixerControl.cbStruct = mcSize; // Get the control details = PCWin32.mixerGetLineControlsA(i, ref lineControls, VolumeConstants.MIXER_GETLINECONTROLSF_ONEBYTYPE); //once again check to see if we received any errors if (VolumeConstants.MMSYSERR_NOERROR == details) { bReturn = true; //Copy the control into the destination structure mixerControl = (VolumeStructs.Mixer)Marshal.PtrToStructure(lineControls.pamxctrl, typeof(VolumeStructs.Mixer)); } else { bReturn = false; } int mcDetailsSize = Marshal.SizeOf(typeof(VolumeStructs.MixerDetails)); int mcDetailsUnsigned = Marshal.SizeOf(typeof(VolumeStructs.UnsignedMixerDetails)); mcDetails.cbStruct = mcDetailsSize; mcDetails.dwControlID = mixerControl.dwControlID; mcDetails.paDetails = Marshal.AllocCoTaskMem(mcDetailsUnsigned); mcDetails.cChannels = 1; mcDetails.item = 0; mcDetails.cbDetails = mcDetailsUnsigned; details = PCWin32.mixerGetControlDetailsA(i, ref mcDetails, VolumeConstants.MIXER_GETCONTROLDETAILSF_VALUE); detailsUnsigned = (VolumeStructs.UnsignedMixerDetails)Marshal.PtrToStructure(mcDetails.paDetails, typeof(VolumeStructs.UnsignedMixerDetails)); currVolume = detailsUnsigned.dwValue; return bReturn; } bReturn = false; return bReturn; }