unit DShowAudioVolume;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ComCtrls, Vcl.StdCtrls, Vcl.ExtCtrls;

type
  TDlgShowAudioVolume = class(TForm)
    pgVol: TProgressBar;
    lbVol: TLabel;
    tHide: TTimer;
    procedure tHideTimer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    Constructor Create(aOwner: TComponent); override;
    Destructor Destroy; override;

    procedure SetVolume(nVol: Integer);
  end;

var
  DlgShowAudioVolume: TDlgShowAudioVolume;

implementation

{$R *.dfm}

const
  SHOW_MILISECOND = 3000;

var
  _nShowTime: Integer = 0;

Constructor TDlgShowAudioVolume.Create(aOwner: TComponent);
begin
  Inherited Create(aOwner);
end;

Destructor TDlgShowAudioVolume.Destroy;
begin
  Inherited;
end;

procedure TDlgShowAudioVolume.SetVolume(nVol: Integer);
begin
  _nShowTime := 0;
  pgVol.Position := nVol;
  lbVol.Caption := Format('%d%%', [nVol]);
  Show;
  Application.ProcessMessages;
end;

procedure TDlgShowAudioVolume.tHideTimer(Sender: TObject);
begin
  if Showing then
  begin
    Inc(_nShowTime, 100);
    if _nShowTime = SHOW_MILISECOND then
      Hide;
  end;
end;

end.