【Delphi】Vista以上系统的进程静音

单个进程的音量控制是从Vista系统中才开始支持的，所以此函数需要在Vista及以上的系统中使用。

XP下面使用这个函数会导致系统全局静音。所以在XP下要使进程静音要使用Hook技术，可以参见另一篇：http://blog.csdn.net/aqtata/article/details/8112092

 

Delphi XE + Win7 x64 编译测试通过

uses
  MMSystem;

function EnableMute(const Mute: Boolean): Boolean;
var
  hmx: HMIXER;
  mxlc: MIXERLINECONTROLS;
  mxl: MIXERLINE;
  mxc: MIXERCONTROL;
  mxcd: tMIXERCONTROLDETAILS;
  mxcdMute: MIXERCONTROLDETAILS_BOOLEAN;
begin
  Result := False;

  if Win32MajorVersion < 6 then
    Exit;

  if mixerOpen(@hmx, 0, 0, 0, 0) <> MMSYSERR_NOERROR then
    Exit;

  mxl.cbStruct := SizeOf(mxl);
  mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
  if mixerGetLineInfo(hmx, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE) = MMSYSERR_NOERROR then
  begin
    mxlc.cbStruct := SizeOf(MIXERLINECONTROLS);
    mxlc.dwLineID := mxl.dwLineID;
    mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE;
    mxlc.cControls := 1;
    mxlc.cbmxctrl := SizeOf(MIXERCONTROL);
    mxlc.pamxctrl := @mxc;
    if mixerGetLineControls(hmx, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE) = MMSYSERR_NOERROR then
    begin
      mxcdMute.fValue := Integer(Mute);
      mxcd.hwndOwner := 0;
      mxcd.dwControlID := mxc.dwControlID;
      mxcd.cbStruct := SizeOf(mxcd);
      mxcd.cbDetails := SizeOf(mxcdMute);
      mxcd.paDetails := @mxcdMute;
      mxcd.cChannels := 1;
      mxcd.cMultipleItems := 0;
      Result := mixerSetControlDetails(hmx, @mxcd, MIXER_OBJECTF_HMIXER or MIXER_SETCONTROLDETAILSF_VALUE) = MMSYSERR_NOERROR;
    end;
  end;

  mixerClose(hmx);
end;