【delphi开源代码栏目提醒】：网学会员,鉴于大家对delphi开源代码十分关注，论文会员在此为大家搜集整理了“frm_CheckOnLine.pas”一文，供大家参考学习!

    unit frm_CheckOnLine;
    
    interface
    
    uses
      Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
      Dialogs,WinInet, StdCtrls, XPMan, ComCtrls;
    
    type
      TFrmCheckOnline = class(TForm)
        GroupBox1: TGroupBox;
        ANi: TAnimate;
        XPManifest1: TXPManifest;
        GroupBox2: TGroupBox;
        BtnCheck: TButton;
        BtnClose: TButton;
        procedure BtnCheckClick(Sender: TObject);
        procedure FormCreate(Sender: TObject);
        procedure BtnCloseClick(Sender: TObject);
      private
        function CheckOffline: boolean;
         { Private declarations }
      public
        { Public declarations }
      end;
    
    var
      FrmCheckOnline: TFrmCheckOnline;
    
    implementation
    
    {$R *.dfm}
    
    function TFrmCheckOnline.CheckOffline: boolean;
    var
      ConnectState: DWORD;
      StateSize: DWORD;
    begin
      ConnectState:= 0;
      StateSize:= SizeOf(ConnectState);
      InternetQueryOption(nil, INTERNET_OPTION_CONNECTED_STATE, @ConnectState, StateSize);
      if (ConnectState and INTERNET_STATE_DISCONNECTED) = INTERNET_STATE_DISCONNECTED then
        result:= true
      else
        result:= false;
    end;
    
    procedure TFrmCheckOnline.BtnCheckClick(Sender: TObject);
    begin
      ani.Visible:=true;
      if CheckOffline then
      begin
        ani.Active:=false;
        showmessage('没在线！');
      end
      else
      begin
        ani.Active:=true;
        showmessage('在线！');
      end;
    end;
    
    procedure TFrmCheckOnline.FormCreate(Sender: TObject);
    begin
      ani.Visible:=false;
    end;
    
    procedure TFrmCheckOnline.BtnCloseClick(Sender: TObject);
    begin
      Close;
    end;
    
    end.