delphi – 如何直接播放没有相关应用程序的声音文件(mp3,wav等)

以下是如何控制设备的音量：

uses MMSystem;

type
   TVolumeRec = record
     case Integer of
       0: (LongVolume: Longint) ;
       1: (LeftVolume,RightVolume : Word) ;
     end;

const DeviceIndex=5
       {0:Wave
        1:MIDI
        2:CDAudio
        3:Line-In
        4:Microphone
        5:Master
        6:PC-loudspeaker}

procedure SetVolume(aVolume:Byte) ;
var 
  Vol: TVolumeRec;
begin
   Vol.LeftVolume := aVolume shl 8;
   Vol.RightVolume:= Vol.LeftVolume;
   auxSetVolume(UINT(DeviceIndex),Vol.LongVolume) ;
end;

function GetVolume:Cardinal;
var 
  Vol: TVolumeRec;
begin
   AuxGetVolume(UINT(DeviceIndex),@Vol.LongVolume) ;
   Result:=(Vol.LeftVolume + Vol.RightVolume) shr 9;
end;