unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
  driver:pchar;
  sec1, byt1, cl1, cl2:longword;
begin
  driver:=pchar(edit1.text);//要顯示的驅動器名
  GetDiskFreeSpace(driver, sec1, byt1, cl1, cl2);
  cl1 := cl1*sec1 * byt1;
  cl2 := cl2*sec1 * byt1;
  Label1.Caption:= '該驅動器總共容量' + Formatfloat('###,##0',cl2) + '字節';
  Label2.Caption := '該驅動器可用容量' + Formatfloat('###,##0',cl1) + '字節';
end;

end.