TServerSocket和TClientSocket做的C/S程序,网络断开,断电等的问题

Question

TServerSocket和TClientSocket做的C/S程序,如果ClientSocket端的计算机突然断电，当机，网线断开，TServerSocket如果才能快速的知道,反之,如果是TServerSocket端的计算机突然断电，当机，网线断开，TClientSocket如果才能快速的知道.
请高手帮忙.如有DEMO发给我[email protected]

Answer 1

在ClientSocketDisconnect，ServerSocketClientDisconnect这个事件里判断

Answer 2

在ClientSocketDisconnect，ServerSocketClientDisconnect这个事件里判断在这两个事件里,断电的情况是不会触发这两个事件的.

Answer 3

或者看看能不能把tcp自己的timeout时间改短一点

Answer 4

能不能写点代码给我看下啊,都搞了好几个星期了,烦啊
最好有DEMO

Answer 5

这两个控件很少用
在服务器程序退出的情况下在ClientSocketDisconnect，ServerSocketClientDisconnect这个事件里可以判断，如果断电，网络断开可能用这个是判断不出来
用TIdIcmpClient定时ping主机，断电，网络不通的话都可以检测出来

Answer 6

控件例子unit Main;interfaceuses
  {$IFDEF Linux}
  QGraphics, QControls, QForms, QDialogs, QStdCtrls, QExtCtrls,
  {$ELSE}
  windows, messages, graphics, controls, forms, dialogs, stdctrls, extctrls,
  {$ENDIF}
  SysUtils, Classes, IdIcmpClient, IdBaseComponent, IdComponent, IdRawBase, IdRawClient;
type
  TfrmPing = class(TForm)
  lstReplies: TListBox;
  ICMP: TIdIcmpClient;
  Panel1: TPanel;
  btnPing: TButton;
  edtHost: TEdit;
  procedure btnPingClick(Sender: TObject);
  procedure ICMPReply(ASender: TComponent; const ReplyStatus: TReplyStatus);
  private
  public
  end;var
  frmPing: TfrmPing;implementation
{$IFDEF MSWINDOWS}{$R *.dfm}{$ELSE}{$R *.xfm}{$ENDIF}procedure TfrmPing.btnPingClick(Sender: TObject);
var
  i: integer;
begin
  ICMP.OnReply := ICMPReply;
  ICMP.ReceiveTimeout := 1000;
  btnPing.Enabled := False; try
  ICMP.Host := edtHost.Text;
  for i := 1 to 4 do begin
  ICMP.Ping;
  Application.ProcessMessages;
  //Sleep(1000);
  end;
  finally btnPing.Enabled := True; end;
end;procedure TfrmPing.ICMPReply(ASender: TComponent; const ReplyStatus: TReplyStatus);
var
  sTime: string;
begin
  // TODO: check for error on ping reply (ReplyStatus.MsgType?)
  if (ReplyStatus.MsRoundTripTime = 0) then
  sTime := '<1'
  else
  sTime := '=';  lstReplies.Items.Add(Format('%d bytes from %s: icmp_seq=%d ttl=%d time%s%d ms',
  [ReplyStatus.BytesReceived,
  ReplyStatus.FromIpAddress,
  ReplyStatus.SequenceId,
  ReplyStatus.TimeToLive,
  sTime,
  ReplyStatus.MsRoundTripTime]));
end;end.

Answer 7

几次ping 不通的话就断开连接从新连，有个缺点，可能防火墙会设置禁止ping命令，ping不通其实网络是通的，这个要具体分析了，或者在协议里自己加心跳校验

Answer 8

打开TCP/IP的KeepAlive机制，把检测超时设短点，就可以自动检测。

Answer 9

solestar(孤星)通用做法是在协议里增加双向的心跳命令这样的方法怎么样实现啊?

Answer 10

用indy或者socket api吧，你这两个控件我不熟悉，没找到关于心跳方面的用法，IdSocket有心跳机制
procedure SetSockOpt(level: Integer; optname: Integer; optval: PChar; optlen: Integer);Parameterslevel: IntegerOption level Id_SOL_SOCKET, Id_IPPROTO_TCP, or Id_IPPROTO_IP.
optname: IntegerSocket option to receive the option value.
optval: PCharValue for the requested option.
optlen: IntegerLength of the option value buffer.
例子我就不贴了

Answer 11

现在TClientSocket可以判断TServerSocket端是否在线了,用了个笨方法,
但TServerSocket端还不可以判断TClientSocket端是否在线,请教中?

Answer 12

//使用keepalive
unit utils_socketc;interface
uses IdStackConsts,IdStackWindows,IdWinSock2;const
  IOC_IN               =$80000000;
  IOC_VENDOR           =$18000000;
  SIO_KEEPALIVE_VALS   =IOC_IN or IOC_VENDOR or 4;
type tcp_keepalive=record
    onoff:Longword;
    keepalivetime:Longword;
    keepaliveinterval:Longword;
  end;
//设置KeepAlive用于检测线路是否中断
function SetKeepALive(const SockHandle:integer):Boolean;
implementation
uses typedefc,global_vspmc,showmsgc,inifilefuncv2;
function SetKeepALive(const SockHandle:integer):Boolean;
var
    KeepAliveIn   : tcp_keepalive;
    KeepAliveOut  : tcp_keepalive;
    Status        : Integer; 
    BytesReturned : Cardinal;
    enkeepalive:boolean;
    Akeepalivetime,Akeepaliveinterval:integer; 
begin                              
Result:=false;
//是否启用KeepALive，默认为启用
inifilefuncv2.readsect_boolean_ini(GVspmConfig_ini,
cfg_globalcfg,cfg_enablekeepalive,enkeepalive,cfg_enablekeepalive_def);
if not enkeepalive then exit;
//默认发检测包间隔
inifilefuncv2.readsect_integer_ini(GVspmConfig_ini,
cfg_globalcfg,cfg_keepalivetime,Akeepalivetime,cfg_keepalivetime_def);inifilefuncv2.readsect_integer_ini(GVspmConfig_ini,
cfg_globalcfg,cfg_keepaliveinterval,Akeepaliveinterval,cfg_keepaliveinterval_def);KeepAliveIn.onoff:=1;
//发送检测包间隔
KeepAliveIn.keepalivetime:=Akeepalivetime;
//回应超时，默认情况下，如果出现超时，Windows将重新发送检测包，直到5次全部失败。
KeepAliveIn.keepaliveinterval:=Akeepaliveinterval;
Status:=WSAIoctl(SockHandle, SIO_KEEPALIVE_VALS,
                               @KeepAliveIn,  SizeOf(KeepAliveIn),
                               @KeepAliveOut, SizeOf(KeepAliveOut),
                               @BytesReturned, nil, nil);
if Status <> 0 then
   begin
     showmsgc.showNormal_msg('SetKeepAlive error','');
     exit;
   end;
 Result:=true;
end;end.