unit1.pas

< Delphi网络通信协议分析与应用实现>>一书的源代码。

unit Unit1;

interface

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

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

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject); 
begin 
if GetSystemMetrics(SM_NETWORK) and $0001 = $0001 then
   edit1.text:='Machine is OnLine'
else
   edit1.text:='Machine is OffLine';
end;

end.