c# - 如何以编程方式控制我的电脑的音量？

Question

我有一个没有音乐键的键盘，用于调高和调低我 PC 中音乐的音量、播放、停止等。不懂就this是我的键盘和this不是。

我想在 Windows 和 Delphi 或 C# 中实现键盘 Hook 以在我的键盘中创建音量功能，但我不知道如何通过代码调高和调低音量。我正在尝试 this和 this示例，但没有用(顺便说一句，全部在 Delphi 中)。

你知道怎么用代码调高音量和调低音量吗？

Answer 1

Delphi 代码如下。

我的 keyhook 向我的主窗体发送一条消息，其中包含 LParam 中的 key VK 代码，

procedure TmainFrm.keyHook(var msg: TMessage);
begin
  case msg.LParam of
    VK_VOLUME_UP  : g_mixer.volume := g_mixer.volume + 2048;
    VK_VOLUME_DOWN: g_mixer.volume := g_mixer.volume - 2048;
    VK_VOLUME_MUTE: g_mixer.muted := not g_mixer.muted;
  end;
end;

音量范围是0 .. 65535；带外值会被静默更正。

-

unit Mixer;

interface

type

  Tmixer = class
  protected
    function getMute: boolean; virtual; abstract;
    function getVolume: integer; virtual; abstract;
    procedure setVolume(Value: integer); virtual; abstract;
    procedure setMute(Value: boolean); virtual; abstract;
  public
    property volume: integer read getVolume write setVolume;
    property muted: boolean read getMute write setMute;
  end;

function g_mixer: Tmixer;

implementation

uses
  Windows, MMSystem, MMDevApi_tlb, ComObj, ActiveX, SysUtils;

// ---------------------------------------------------------------------------

type

  TxpMixer = class(Tmixer)
  private
    Fmxct: integer;
    Fmixer: HMIXER;
    procedure chk(r: MMRESULT);
  protected
    function getMute: boolean; override;
    function getVolume: integer; override;
    procedure setVolume(Value: integer); override;
    procedure setMute(Value: boolean); override;
  public
    constructor Create;
    destructor Destroy; override;
  end;

  TvistaMixer = class(Tmixer)
  private
    FmmDev: IMMDevice;
    FmmDevEnum: IMMDeviceEnumerator;
    FmmEndpoint: IMMAudioEndpointVolume;
  protected
    function getMute: boolean; override;
    function getVolume: integer; override;
    procedure setVolume(Value: integer); override;
    procedure setMute(Value: boolean); override;
  public
    constructor Create;
  end;

// ---------------------------------------------------------------------------

var
  _g_mixer: Tmixer;

function g_mixer: Tmixer;
var
  VerInfo: TOSVersioninfo;
begin
  if (_g_mixer = nil) then
  begin
    VerInfo.dwOSVersionInfoSize := SizeOf(TOSVersionInfo);
    GetVersionEx(VerInfo);
    if (VerInfo.dwMajorVersion >= 6) then
      _g_mixer := TvistaMixer.Create
    else
      _g_mixer := TxpMixer.Create;
  end;
  result := _g_mixer;
end;

// ---------------------------------------------------------------------------

{ TxpMixer }

procedure TxpMixer.chk(r: MMRESULT);
var
  s: string;
begin
  if (r = MMSYSERR_NOERROR) then
    exit;
  setLength(s, MMSystem.MAXERRORLENGTH + 1);
  waveOutGetErrorText(r, @s[1], MMSystem.MAXERRORLENGTH);
  raise Exception.Create(StrPas(pChar(s)));
end;

// ---------------------------------------------------------------------------

constructor TxpMixer.Create;
begin
  Fmxct := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
  chk(mixerOpen(@Fmixer, 0, 0, 0, 0));
end;

// ---------------------------------------------------------------------------

destructor TxpMixer.Destroy;
begin
  if (Fmixer <> 0) then
    mixerClose(Fmixer);
  inherited;
end;

// ---------------------------------------------------------------------------

function TxpMixer.getMute: boolean;
var
  MasterMute: TMixerControl;
  Details: TMixerControlDetails;
  BoolDetails: TMixerControlDetailsBoolean;
  Line: TMixerLine;
  Controls: TMixerLineControls;
begin
  ZeroMemory(@Line, SizeOf(Line));
  Line.cbStruct := SizeOf(Line);
  Line.dwComponentType := Fmxct;
  chk(mixerGetLineInfo(0, @Line, MIXER_GETLINEINFOF_COMPONENTTYPE));

  ZeroMemory(@Controls, SizeOf(Controls));
  Controls.cbStruct := SizeOf(Controls);
  Controls.dwLineID := Line.dwLineID;
  Controls.cControls := 1;
  Controls.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE;
  Controls.cbmxctrl := SizeOf(MasterMute);
  Controls.pamxctrl := @MasterMute;
  chk(mixerGetLineControls(0, @Controls, MIXER_GETLINECONTROLSF_ONEBYTYPE));

  Details.cbStruct := SizeOf(Details);
  Details.dwControlID := MasterMute.dwControlID;
  Details.cChannels := 1;
  Details.cMultipleItems := 0;
  Details.cbDetails := SizeOf(BoolDetails);
  Details.paDetails := @BoolDetails;
  chk(mixerGetControlDetails(0, @Details, MIXER_GETCONTROLDETAILSF_VALUE));

  result := BoolDetails.fValue <> 0;
end;

// ---------------------------------------------------------------------------

function TxpMixer.getVolume: integer;
var
  Line: TMixerLine;
  Controls: TMixerLineControls;
  MasterVolume: TMixerControl;
  Details: TMixerControlDetails;
  UnsignedDetails: TMixerControlDetailsUnsigned;
begin
  ZeroMemory(@Line, SizeOf(Line));
  Line.cbStruct := SizeOf(Line);
  Line.dwComponentType := Fmxct;
  chk(mixerGetLineInfo(Fmixer, @Line, MIXER_GETLINEINFOF_COMPONENTTYPE));
  ZeroMemory(@Controls, SizeOf(Controls));
  Controls.cbStruct := SizeOf(Controls);
  Controls.dwLineID := Line.dwLineID;
  Controls.cControls := 1;
  Controls.dwControlType := MIXERCONTROL_CONTROLTYPE_VOLUME;
  Controls.cbmxctrl := SizeOf(MasterVolume);
  Controls.pamxctrl := @MasterVolume;
  chk(mixerGetLineControls(Fmixer, @Controls, MIXER_GETLINECONTROLSF_ONEBYTYPE));

  details.cbStruct := SizeOf(Details);
  details.dwControlID := MasterVolume.dwControlID;
  details.cChannels := 1;
  details.cMultipleItems := 0;
  details.cbDetails := SizeOf(UnsignedDetails);
  details.paDetails := @UnsignedDetails;
  chk(mixerGetControlDetails(Fmixer, @Details, MIXER_GETCONTROLDETAILSF_VALUE));
  result := UnsignedDetails.dwValue;
end;

// ---------------------------------------------------------------------------

procedure TxpMixer.setMute(Value: boolean);
var
  Line: TMixerLine;
  Controls: TMixerLineControls;
  MasterMute: TMixerControl;
  Details: TMixerControlDetails;
  BoolDetails: TMixerControlDetailsBoolean;
begin
  ZeroMemory(@Line, SizeOf(Line));
  Line.cbStruct := SizeOf(Line);
  Line.dwComponentType := Fmxct;
  chk(mixerGetLineInfo(Fmixer, @Line, MIXER_GETLINEINFOF_COMPONENTTYPE));
  ZeroMemory(@Controls, SizeOf(Controls));
  Controls.cbStruct := SizeOf(Controls);
  Controls.dwLineID := Line.dwLineID;
  Controls.cControls := 1;
  Controls.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE;
  Controls.cbmxctrl := SizeOf(masterMute);
  Controls.pamxctrl := @masterMute;
  chk(mixerGetLineControls(Fmixer, @Controls, MIXER_GETLINECONTROLSF_ONEBYTYPE));

  details.cbStruct := SizeOf(Details);
  details.dwControlID := MasterMute.dwControlID;
  details.cChannels := 1;
  details.cMultipleItems := 0;
  details.cbDetails := SizeOf(BoolDetails);
  details.paDetails := @BoolDetails;
  mixerGetControlDetails(0, @Details, MIXER_GETCONTROLDETAILSF_VALUE);
  if (Value) then
    BoolDetails.fValue := 1
  else
    BoolDetails.fValue := 0;

  chk(mixerSetControlDetails(0, @Details, MIXER_SETCONTROLDETAILSF_VALUE));
end;

// ---------------------------------------------------------------------------

procedure TxpMixer.setVolume(Value: integer);
var 
  Line: TMixerLine;
  Controls: TMixerLineControls;
  MasterVolume: TMixerControl;
  Details: TMixerControlDetails;
  UnsignedDetails: TMixerControlDetailsUnsigned;
begin
  if (value < 0) then
    value := 0;
  if (value > 65535) then
    value := 65535;

  ZeroMemory(@Line, SizeOf(Line));
  Line.cbStruct := SizeOf(Line);
  Line.dwComponentType := Fmxct;
  chk(mixerGetLineInfo(Fmixer, @Line, MIXER_GETLINEINFOF_COMPONENTTYPE));
  ZeroMemory(@Controls, SizeOf(Controls));
  Controls.cbStruct := SizeOf(Controls);
  Controls.dwLineID := Line.dwLineID;
  Controls.cControls := 1;
  Controls.dwControlType := MIXERCONTROL_CONTROLTYPE_VOLUME;
  Controls.cbmxctrl := SizeOf(MasterVolume);
  Controls.pamxctrl := @MasterVolume;
  chk(mixerGetLineControls(Fmixer, @Controls, MIXER_GETLINECONTROLSF_ONEBYTYPE));

  details.cbStruct := SizeOf(Details);
  details.dwControlID := MasterVolume.dwControlID;
  details.cChannels := 1;
  details.cMultipleItems := 0;
  details.cbDetails := SizeOf(UnsignedDetails);
  details.paDetails := @UnsignedDetails;
  UnsignedDetails.dwValue := Value;
  chk(mixerSetControlDetails(Fmixer, @Details, MIXER_SETCONTROLDETAILSF_VALUE));
end;

// ---------------------------------------------------------------------------

{ TvistaMixer }

constructor TvistaMixer.Create;
begin
  CoCreateInstance(CLSID_MMDeviceEnumerator, nil, CLSCTX_ALL, IID_IMMDeviceEnumerator, FmmDevEnum);
  FmmDevEnum.GetDefaultAudioEndpoint(eRender, eMultimedia, FmmDev);
  FmmDev.Activate(IID_IAudioEndpointVolume, CLSCTX_ALL, nil, FmmEndpoint);
end;

// ---------------------------------------------------------------------------

function TvistaMixer.getMute: boolean;
begin
  FmmEndpoint.GetMute(Result);
end;

// ---------------------------------------------------------------------------

function TvistaMixer.getVolume: integer;
var
  VolLevel: Single;
begin
  FmmEndpoint.GetMasterVolumeLevelScalar(VolLevel);
  result := Round(VolLevel * 65535);
end;

// ---------------------------------------------------------------------------

procedure TvistaMixer.setMute(Value: boolean);
begin
  FmmEndpoint.SetMute(Value, nil);
end;

// ---------------------------------------------------------------------------

procedure TvistaMixer.setVolume(Value: integer);
var 
  fValue: Single;
begin
  if (value < 0) then
    value := 0;
  if (value > 65535) then
    value := 65535;
  fValue := Value / 65535;
  FmmEndpoint.SetMasterVolumeLevelScalar(fValue, nil);
end;

// ---------------------------------------------------------------------------

end.

-

unit MMDevApi_tlb;

interface
  uses Windows, ActiveX, Classes, Graphics, OleServer, OleCtrls, StdVCL,ComObj;
const
  // TypeLibrary Major and minor versions

  CLSID_MMDeviceEnumerator: TGUID               = '{BCDE0395-E52F-467C-8E3D-C4579291692E}';
  IID_IMMDeviceEnumerator: TGUID                = '{A95664D2-9614-4F35-A746-DE8DB63617E6}';
  IID_IMMDevice: TGUID                          = '{D666063F-1587-4E43-81F1-B948E807363F}';
  IID_IMMDeviceCollection: TGUID                = '{0BD7A1BE-7A1A-44DB-8397-CC5392387B5E}';
  IID_IAudioEndpointVolume: TGUID               = '{5CDF2C82-841E-4546-9722-0CF74078229A}';
  IID_IAudioMeterInformation : TGUID            = '{C02216F6-8C67-4B5B-9D00-D008E73E0064}';
  IID_IAudioEndpointVolumeCallback: TGUID       = '{657804FA-D6AD-4496-8A60-352752AF4F89}';
  GUID_NULL: TGUID                              = '{00000000-0000-0000-0000-000000000000}';

  DEVICE_STATE_ACTIVE                   = $00000001;
  DEVICE_STATE_UNPLUGGED                = $00000002;
  DEVICE_STATE_NOTPRESENT               = $00000004;
  DEVICE_STATEMASK_ALL                  = $00000007;

type
  EDataFlow = TOleEnum;
const
  eRender                               = $00000000;
  eCapture                              = $00000001;
  eAll                                  = $00000002;
  EDataFlow_enum_count                  = $00000003;

type
  ERole = TOleEnum;
const
  eConsole                              = $00000000;
  eMultimedia                           = $00000001;
  eCommunications                       = $00000002;
  ERole_enum_count                      = $00000003;

type
  IAudioEndpointVolumeCallback = interface(IUnknown)
  ['{657804FA-D6AD-4496-8A60-352752AF4F89}']
  end;

  IMMAudioEndpointVolume = interface(IUnknown)
  ['{5CDF2C82-841E-4546-9722-0CF74078229A}']
    Function RegisterControlChangeNotify( AudioEndPtVol: IAudioEndpointVolumeCallback): Integer; stdcall;
    Function UnregisterControlChangeNotify( AudioEndPtVol: IAudioEndpointVolumeCallback): Integer; stdcall;
    Function GetChannelCount(out PInteger): Integer; stdcall;
    Function SetMasterVolumeLevel(fLevelDB: single; pguidEventContext: PGUID):Integer; stdcall;
    Function SetMasterVolumeLevelScalar(fLevelDB: single; pguidEventContext: PGUID):Integer; stdcall;
    Function GetMasterVolumeLevel(out fLevelDB: single):Integer; stdcall;
    Function GetMasterVolumeLevelScalar(out fLevel: single):Integer; stdcall;
    Function SetChannelVolumeLevel(nChannel: Integer; fLevelDB: double; pguidEventContext: TGUID):Integer; stdcall;
    Function SetChannelVolumeLevelScalar(nChannel: Integer; fLevelDB: single; pguidEventContext: TGUID):Integer; stdcall;
    Function GetChannelVolumeLevel(nChannel: Integer; out fLevelDB: double) : Integer; stdcall;
    Function GetChannelVolumeLevelScalar(nChannel: Integer; out fLevel: double) : Integer; stdcall;
    Function SetMute(bMute: Boolean ; pguidEventContext: PGUID) :Integer; stdcall;
    Function GetMute(out bMute: Boolean ) :Integer; stdcall;
    Function GetVolumeStepInfo( pnStep: Integer; out pnStepCount: Integer):Integer; stdcall;
    Function VolumeStepUp(pguidEventContext: TGUID) :Integer; stdcall;
    Function VolumeStepDown(pguidEventContext: TGUID) :Integer; stdcall;
    Function QueryHardwareSupport(out pdwHardwareSupportMask): Integer; stdcall;
    Function GetVolumeRange(out pflVolumeMindB: double; out pflVolumeMaxdB: double; out pflVolumeIncrementdB: double): Integer; stdcall;
  end;

  IPropertyStore = interface(IUnknown)
  end;

type
  IMMDevice = interface(IUnknown)
  ['{D666063F-1587-4E43-81F1-B948E807363F}']
    Function Activate(  const refId :TGUID;
                        dwClsCtx: DWORD;
                        pActivationParams: PInteger ;
                        out pEndpointVolume: IMMAudioEndpointVolume): Hresult; stdCall;
    Function OpenPropertyStore(stgmAccess: DWORD; out ppProperties :IPropertyStore): Hresult; stdcall;
    Function GetId(out ppstrId: PLPWSTR ): Hresult; stdcall;
    Function GetState(out State :Integer): Hresult; stdcall;
  end;

  IMMDeviceCollection = interface(IUnknown)
  ['{0BD7A1BE-7A1A-44DB-8397-CC5392387B5E}']
  end;

  IMMNotificationClient = interface (IUnknown)
  ['{7991EEC9-7E89-4D85-8390-6C703CEC60C0}']
  end;

  IMMDeviceEnumerator = interface(IUnknown)
  ['{A95664D2-9614-4F35-A746-DE8DB63617E6}']
    Function EnumAudioEndpoints( dataFlow: EDataFlow; deviceState: SYSUINT; DevCollection:IMMDeviceCollection ): Hresult ; stdcall;
    Function GetDefaultAudioEndpoint(EDF: SYSUINT; ER: SYSUINT; out Dev :IMMDevice ): Hresult ; stdcall;
    Function GetDevice( pwstrId: pointer ; out Dev :IMMDevice) : HResult; stdcall;
    Function RegisterEndpointNotificationCallback(pClient :IMMNotificationClient) :Hresult; stdcall;
  end;

  implementation
end.