unit1.~pas

delphi编写的

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    GroupBox1: TGroupBox;
    Label1: TLabel;
    edtStatus: TEdit;
    GroupBox2: TGroupBox;
    btnCheck: TButton;
    btnExit: TButton;
    procedure btnCheckClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.btnCheckClick(Sender: TObject);
var
   Types : Integer;
begin
   Types := INTERNET_CONNECTION_MODEM +
            INTERNET_CONNECTION_LAN +
            INTERNET_CONNECTION_PROXY;
   //检查三种网络状况
    if InternetGetConnectedState(@types, 0) then
       edtStatus.Text := '你的电脑已与网络连接'
    else
       edtStatus.Text := '你的电脑未与网络连接';
end;

end.