Indy 10.6 在具有管理员权限的 Linux 系统上使用 tcpserver 在客户端断开连接时抛出 Gtk-WARNING答案

【问题标题】：Indy 10.6 using tcpserver on Linux system with admin rights throws Gtk-WARNING when client disconnectsIndy 10.6 在具有管理员权限的 Linux 系统上使用 tcpserver 在客户端断开连接时抛出 Gtk-WARNING
【发布时间】：2017-01-26 18:14:59
【问题描述】：

我正在 Raspberry PI 上使用 Indy 10.6 tcpserver 设置一个新系统，并加载了最新的 Raspbian。我正在通过带有 sudo 的终端 bash 脚本从 GUI 桌面运行该应用程序。在客户端连接之前一切正常，然后当它断开连接时我得到 Gtk-WARNINGs，有时是 Gtk-CRITICALs，我不知道为什么。这是我的代码，它一次只允许一个客户端连接，然后它会停用服务器并在每个连接完成后重新启动它：

Procedure TFK20Elevator.ASpeedBtn1Click(Sender: TObject);
Begin //start the server
  Server.Active := False;
  Server.Bindings.Clear;
  Server.Bindings.Add.IPVersion := Id_IPv4;
  Server.Bindings.Add.IP := LIP;
  Server.Bindings.Add.Port := DefPort + StrToIntDef(UnitID, 0);
  Try
    Server.Active := True;
  Except
    On E: Exception Do
      Memo1.Lines.Add(E.Message);
  End;
  If Not Server.Active Then
    Exit;
  ASpeedBtn1.Enabled := False;
  ASpeedBtn2.Enabled := True;
  AStatus1.SimpleText := 'Server bound to ' + LIP + ':' + IntToStr(DefPort + StrToIntDef(UnitID, 0));
End;

Procedure TFK20Elevator.ServerConnect(AContext: TIdContext);
Begin
  If Connected Then
    Begin
      Abort();
      Exit;
    End;
  AStatus1.SimpleText := 'Connecting to> ' + AContext.Binding.PeerIP + ' - Authenticating...';
  Memo1.Lines.Clear;
  Manager := False;
  EncDecSIdx := 1;
  RetryTimer.Enabled := False;
  RetryTimer.Interval := 3000;
  Authenticating := True;
  AuthTimer.Enabled := True;
  StayAlive.Enabled := True;
End;

Procedure TFK20Elevator.ServerException(AContext: TIdContext; AException: Exception);
Begin
  If AnsiContainsText(AException.Message, 'Gracefully') Then
    AStatus1.SimpleText := 'Server bound to ' + LIP + ':' + IntToStr(DefPort + StrToIntDef(UnitID, 0)) //closed gracefully message
  Else
    Begin //show the exception
      Memo1.Lines.Add('An exception happend! - ' + AException.Message);
      RetryTimer.Enabled := True;
    End;
  Manager := False;
  Authenticating := False;
End;

Procedure TFK20Elevator.ServerExecute(AContext: TIdContext);
//EncStr and DecStr simply encode/decode, respectively, a standard
//  string into/from a key encrypted hex string, i.e. '00' to 'FF'
//  for each character in the string
Var
  S, UserName, Password: String;
  I, N: Integer;
Begin
  S := AContext.Connection.IOHandler.ReadLn(IndyTextEncoding_OSDefault, IndyTextEncoding_OSDefault); //get the data
  If S = Heart Then //if message is the client heart beat, return to client
    Begin //just a heart beat, reset timer
      StayAlive.Enabled := False;
      AContext.Connection.IOHandler.WriteLn(Heart, IndyTextEncoding_OSDefault, IndyTextEncoding_OSDefault);
      StayAlive.Enabled := True;
      Exit;
    End;
  S := PCommon.DecStr(S, EncDecStr, EncDecSIdx); //not heart beat, decompress
  If Authenticating Then
    Begin //test log in
      If Length(S) > 3 Then
        Begin
          I := Pos('|', S);
          If (I > 1) And (Length(S) > I) Then
            Begin
              UserName := Copy(S, 1, I - 1);
              Password := Copy(S, I + 1, Length(S) - I);
              If UserName = ManUser Then
                Begin
                  If Password = ManPass Then
                    Begin
                      AuthTimer.Enabled := False;
                      Manager := True;
                      Authenticating := False;
                      AContext.Connection.IOHandler.WriteLn(EncStr(AContext.Binding.PeerIP +
                                                            ':' + IntToStr(DefPort + StrToIntDef(UnitID, 0)) + 'M',
                                                            EncDecStr, EncDecSIdx), IndyTextEncoding_OSDefault,
                                                            IndyTextEncoding_OSDefault);
                      AStatus1.SimpleText := 'Connecting to> ' + AContext.Binding.PeerIP + ' as Manager';
                      Connected := True;
                    End
                  Else
                    AuthTimerTimer(Self);
                End
              Else If UserName = GenUser Then
                Begin
                  If Password = GenPass Then
                    Begin
                      AuthTimer.Enabled := False;
                      Authenticating := False;
                      AContext.Connection.IOHandler.WriteLn(EncStr(AContext.Binding.PeerIP +
                                                            ':' + IntToStr(DefPort + StrToIntDef(UnitID, 0)) + 'U',
                                                            EncDecStr, EncDecSIdx), IndyTextEncoding_OSDefault,
                                                            IndyTextEncoding_OSDefault);
                      AStatus1.SimpleText := 'Connecting to> ' + AContext.Binding.PeerIP + ' as General User';
                      Connected := True;
                    End
                  Else
                    AuthTimerTimer(Self);
                End
              Else
                AuthTimerTimer(Self);
            End
          Else
            AuthTimerTimer(Self);
        End
      Else
        AuthTimerTimer(Self);
    End
  Else
    Begin //test for commands
      If Copy(S, 1, Length(AssignID)) = AssignID Then
        Begin //command to assign a new unit id
          NewLoc := DefLocation;
          NewUnit := DefUnitNum;
          I := Pos('-', S, 1);
          If (I > 0) And (I < Length(S)) Then
            Begin
              N := Pos('-', S, I + 1);
              If (N > 0) And (N < Length(S)) Then
                Begin
                  NewLoc := Copy(S, I + 1, N - I - 1);
                  NewUnit := Copy(S, N + 1, Length(S) - N);
                End;
            End;
          Label15.Caption := NewLoc;
          Label16.Caption := NewUnit;
          FmtStr(LIP, '%.3d', [StrToInt(NewUnit)]);
          LIP := '192.168.6' + Copy(LIP, 1, 1) + '.' + Copy(LIP, 2, 2); //wifi ip
          Memo1.Lines.Add('--> ' + S + '-' + LIP);
          AContext.Connection.IOHandler.WriteLn(PCommon.EncStr(Rebooting, EncDecStr, EncDecSIdx),
                                                IndyTextEncoding_OSDefault, IndyTextEncoding_OSDefault);
          Memo1.Lines.Add('<-- ' + Rebooting);
          TestTimer.Enabled := True;
        End;
    End;
End;

Procedure TFK20Elevator.ASpeedBtn2Click(Sender: TObject);
Begin //shut down the server with optional restart if not rebooting
  AuthTimer.Enabled := False;
  RetryTimer.Enabled := False;
  StayAlive.Enabled := False;
  TestTimer.Enabled := False;
  DropClient;
  Try
    Server.Active := False;
  Except
    On E: Exception Do
      Memo1.Lines.Add('Error disconnecting server - ' + E.Message);
  End;
  If Server.Active Then
    Exit;
  ASpeedBtn1.Enabled := True;
  ASpeedBtn2.Enabled := False;
  AStatus1.SimpleText := 'Server not running...';
  Manager := False;
  Authenticating := False;
  Connected := False;
  RetryTimer.Enabled := Not SysReboot;
End;

Procedure TFK20Elevator.ServerDisconnect(AContext: TIdContext);
Begin
  StayAlive.Enabled := False;
  RetryTimer.Enabled := False;
  DropClient;
  AStatus1.SimpleText := 'Client disconnected...';
  Manager := False;
  Authenticating := False;
  Connected := False;
  RetryTimer.Enabled := Not SysReboot;
End;

Procedure TFK20Elevator.DropClient; //make sure buffers are cleared
Var
  I: Integer;
  SC: TIdContext;
Begin
  If Server.Active Then
    Begin
      Application.ProcessMessages;
      With Server.Contexts.LockList Do
        Try
          Memo1.Lines.Add('Disconnecting...');
          For I := Count - 1 DownTo 0 Do
            Begin
              SC := TIdContext(Items[I]);
              If SC = Nil Then
                Continue;
              SC.Connection.IOHandler.WriteBufferClear;
              SC.Connection.IOHandler.InputBuffer.Clear;
              SC.Connection.IOHandler.Close;
              If SC.Connection.Connected Then
                SC.Connection.Disconnect;
              Memo1.Lines.Add('Disconnecting client ' + IntToStr(I + 1) + ' of ' + IntToStr(Count));
            End;
        Finally
          Server.Contexts.UnlockList;
          Memo1.Lines.Add('Disconnected');
        End;
    End;
End;

Procedure TFK20Elevator.StayAliveTimer(Sender: TObject);
Begin //server reset timer if client stops sending heart beat
  StayAlive.Enabled := False;
  AStatus1.SimpleText := 'Client timed out!';
  If ASpeedBtn2.Enabled Then
    ASpeedBtn2Click(Self);
End;

Procedure TFK20Elevator.AuthTimerTimer(Sender: TObject);
Begin //login authorization timeout timer
  AuthTimer.Enabled := False;
  ASpeedBtn2Click(Self);
  Application.ProcessMessages;
  ASpeedBtn1Click(Self);
End;

【问题讨论】：

也获得了很多 Pango-CRITICALs。尝试在 ServerDisconnect 中禁用 DropClient，但没有帮助。
部分留言：
Pango-CRITICAL **：pango_layout_get_context：断言“布局！= NULL”失败 Pango-CRITICAL **：pango_context_get_language：断言“上下文！= NULL”失败 Pango-CRITICAL **：pango_context_get_metrics：断言' PANGO_IS_CONTEXT (context)' 失败 Pango-CRITICAL **: pango_font_metrics_get_approximate_char_width: 断言'metrics != NULL' 失败 Pango-CRITICAL **: pango_font_metrics_get_approximate_digit_width: 断言'metrics != NULL' 失败等等。
客户端程序实际上在 Windows 10 下运行，使用 Delphi 7 编写，也使用 Indy 10.6。确认登录后，客户端每 3 秒发送一次简单的心跳代码，如果服务器未返回该代码，则重置其连接。
另外，第二个条件，如果客户端已连接，但突然断开连接（我在调试模式下重置程序），服务器向我发出客户端超时的信号，但随后程序冻结。

标签： linux gtk indy tcpserver disconnect

【解决方案1】：

 Server.Bindings.Add.IPVersion := Id_IPv4;
 Server.Bindings.Add.IP := LIP;
 Server.Bindings.Add.Port := DefPort + StrToIntDef(UnitID, 0);

这是您的代码中的一个错误。您不只是打开 1 个监听套接字，而是实际上打开了 3 个监听套接字！对Bindings.Add() 的每次调用都会告诉TIdTCPServer 创建一个单独的监听套接字，并且每个绑定对象都有自己的IP/端口设置。

您对上述代码的真正作用是：

在端口 TIdTCPServer.DefaultPort 上的 IP 0.0.0.0 上创建 IPv4 绑定。
使用 Indy 的默认 IP 版本在端口 TIdTCPServer.DefaultPort 上创建另一个 IP LIP 绑定（恰好是 IPv4，除非您使用在 IdCompilerDefines.inc 中定义的 IdIPv6 重新编译 Indy）。
根据 Indy 的默认 IP 版本，在端口 DefPort+UnitID 上创建另一个 IP 0.0.0.0 或 ::1 绑定。

对于您正在尝试做的事情，您只需要致电Bindings.Add()一次，例如：

var
  Binding : TIdSocketHandle;

Binding := Server.Bindings.Add;
Binding.IPVersion := Id_IPv4;
Binding.IP := LIP;
Binding.Port := DefPort + StrToIntDef(UnitID, 0);

话虽如此，TIdTCPServer 是一个多线程组件。它的各种事件（OnConnect、OnDisconnect、OnExecute、OnException 和OnListenException）在TIdTCPServer 内部创建的工作线程上下文中触发。您的事件处理程序从主 UI 线程的上下文之外直接访问 UI 控件。这会导致各种问题，绝对不能这样做。

如果您的事件处理程序需要访问您的 UI，它们必须与主 UI 线程同步，例如与 TThread.Synchronize() 或 TThread.Queue()，或 Indy 自己的 TIdSync 或 TIdNotify 类，或任何其他交互您选择的线程同步机制。

此外，当您使用 DropClient() 手动删除客户端时，它会在没有业务的情况下执行操作。无论如何，您甚至都不需要手动删除客户端，因为 TIdTCPServer 在停用时会为您处理。

说了这么多，试试这样的：

interface

uses
  Classes, Form, SysUtils, StdCtrls, ExtCtrls, Buttons, IdTCPServer, IdContext;

type
  TFK20Elevator = class(TForm)
    Server: TIdTCPServer;
    ASpeedBtn1: TSpeedButton;
    ASpeedBtn2: TSpeedButton;
    Memo1: TMemo;
    AStatus1: TStatusBar;
    AuthTimer: TTimer;
    RetryTimer: TTimer;
    StayAlive: TTimer;
    TestTimer: TTimer;
    ...
    procedure ASpeedBtn1Click(Sender: TObject);
    procedure ASpeedBtn2Click(Sender: TObject);
    procedure StayAliveTimer(Sender: TObject);
    procedure AuthTimerTimer(Sender: TObject);
    procedure ServerConnect(AContext: TIdContext);
    procedure ServerDisconnect(AContext: TIdContext);
    procedure ServerException(AContext: TIdContext; AException: Exception);
    procedure ServerExecute(AContext: TIdContext);
    ...
  private
    DefPort: Integer;
    UnitID: string;
    Manager: Boolean;
    Authenticating: Boolean;
    EncDecSIdx: Integer;
    ...
    procedure DropClient;
    procedure ConnectedNotify(const APeerIP: string);
    procedure DisconnectedNotify;
    procedure ErrorNotify(const AMessage: string);
    procedure HeartNotify;
    procedure ManagerLoggedInNotify(const APeerIP: string);
    procedure GeneralUserLoggedInNotify(const APeerIP: string);
    procedure FailedAuthNotify;
    procedure RebootNotify(const Data: string);
    ...
  end;

var
  FK20Elevator: TFK20Elevator;

implementation

uses
  IdGlobal, IdSync;

const
  Heart: string = ...;
  AssignID: string = ...;
  ...

procedure TFK20Elevator.ASpeedBtn1Click(Sender: TObject);
var
  Binding: TIdSocketHandle;
begin
  //start the server

  Server.Active := False;
  Server.Bindings.Clear;
  Binding := Server.Bindings.Add;
  Binding.IPVersion := Id_IPv4;
  Binding.IP := LIP;
  Binding.Port := DefPort + StrToIntDef(UnitID, 0);
  Server.MaxConnections := 1;

  try
    Server.Active := True;
  except
    on E: Exception do
    begin
      Memo1.Lines.Add('Error activating server - ' + E.Message);
      Exit;
    end;
  end;

  AStatus1.SimpleText := 'Server bound to ' + Binding.IP + ':' + IntToStr(Binding.Port);

  ASpeedBtn1.Enabled := False;
  ASpeedBtn2.Enabled := True;
end;

procedure TFK20Elevator.ASpeedBtn2Click(Sender: TObject);
begin
  //shut down the server with optional restart if not rebooting

  AuthTimer.Enabled := False;
  RetryTimer.Enabled := False;
  StayAlive.Enabled := False;
  TestTimer.Enabled := False;

  try
    Server.Active := False;
  except
    on E: Exception do
    begin
      Memo1.Lines.Add('Error deactivating server - ' + E.Message);
      Exit;
    end;
  end;

  Manager := False;
  Authenticating := False;

  AStatus1.SimpleText := 'Server not running...';
  ASpeedBtn1.Enabled := True;
  ASpeedBtn2.Enabled := False;

  RetryTimer.Enabled := not SysReboot;
end;

procedure TFK20Elevator.StayAliveTimer(Sender: TObject);
begin
  //client stopped sending heart beats
  StayAlive.Enabled := False;
  Memo1.Lines.Add('Client timed out!');
  DropClient;
end;

procedure TFK20Elevator.AuthTimerTimer(Sender: TObject);
begin
  //login authorization timeout
  AuthTimer.Enabled := False;
  Memo1.Lines.Add('Authentication timed out!');
  DropClient;
end;

procedure TFK20Elevator.DropClient;
begin
  with Server.Contexts.LockList do
  try
    if Count > 0 then
      TIdContext(Items[0]).Connection.Disconnect;        
  finally
    Server.Contexts.UnlockList;
  end;
end;

type
  TMyNotifyMethod = procedure(const AStr: string) of object;

  TMyNotify = class(TIdNotify)
  protected
    FMethod: TMyNotifyMethod;
    FStr: string;
    procedure DoNotify; override;
  public
    class procedure NotifyStr(AMethod: TMyNotifyMethod; const AStr: string);
  end;

procedure TMyNotify.DoNotify;
begin
  FMethod(FStr);
end;

class procedure TMyNotify.NotifyStr(AMethod: TMyNotifyMethod; const AStr: string);
begin
  with Create do
  begin
    FMethod := AMethod;
    FStr := AStr;
    Notify;
  end;
end;

procedure TFK20Elevator.ConnectedNotify(const APeerIP: string);
begin
  if not Server.Active then Exit;
  AStatus1.SimpleText := 'Connecting to> ' + APeerIP + ' - Authenticating...';
  Memo1.Lines.Clear;
  RetryTimer.Enabled := False;
  RetryTimer.Interval := 3000;
  AuthTimer.Enabled := True;
  StayAlive.Enabled := True;
end;

procedure TFK20Elevator.DisconnectedNotify;
begin
  StayAlive.Enabled := False;
  RetryTimer.Enabled := False;

  if Server.Active then
  begin
    with Server.Bindings[0] do
      AStatus1.SimpleText := 'Client Disconnected. Server bound to ' + IP + ':' + IntToStr(Port);
  end;

  RetryTimer.Enabled := Not SysReboot;
end;

procedure TFK20Elevator.ErrorNotify(const AMessage: string);
begin
  Memo1.Lines.Add('An exception happened! - ' + AMessage);
  RetryTimer.Enabled := True;
end;

procedure TFK20Elevator.HeartNotify;
begin
  StayAlive.Enabled := False;
  StayAlive.Enabled := True;
end;

procedure TFK20Elevator.ManagerLoggedInNotify(const APeerIP: string);
begin
  AuthTimer.Enabled := False;
  AStatus1.SimpleText := 'Connecting to> ' + APeerIP + ' as Manager';
end;

procedure TFK20Elevator.GeneralUserLoggedInNotify(const APeerIP: string);
begin
  AuthTimer.Enabled := False;
  AStatus1.SimpleText := 'Connecting to> ' + APeerIP + ' as General User';
end;

procedure TFK20Elevator.FailedAuthNotify;
begin
  //login authorization failed
  AuthTimer.Enabled := False;
end;

procedure TFK20Elevator.RebootNotify(const Data: string);
var
  Tmp, S, NewLoc, NewUnit, LIP: string;
begin
  Tmp := Data;

  S := Fetch(Tmp, #10);
  NewLoc := Fetch(Tmp, #10);
  NewUnit := Tmp;

  Label15.Caption := NewLoc;
  Label16.Caption := NewUnit;

  FmtStr(LIP, '%.3d', [StrToInt(NewUnit)]);
  LIP := '192.168.6' + Copy(LIP, 1, 1) + '.' + Copy(LIP, 2, 2); //wifi ip

  Memo1.Lines.Add('--> ' + S + '-' + LIP);
  Memo1.Lines.Add('<-- ' + Rebooting);

  TestTimer.Enabled := True;
end;

procedure TFK20Elevator.ServerConnect(AContext: TIdContext);
begin
  Manager := False;
  Authenticating := True;
  EncDecSIdx := 1;

  TMyNotify.NotifyStr(@ConnectedNotify, AContext.Binding.PeerIP);

  // Note: OSDefault is platform-specific. On Linux, it is UTF-8, so
  // you should use UTF-8 explicitly instead, so as to provide
  // better compatibility across platforms, especially if you ever
  // move this server code to another platform in the future...
  //
  AContext.Connection.IOHandler.DefStringEncoding := IndyTextEncoding_OSDefault; // IndyTextEncoding_UTF8
  AContext.Connection.IOHandler.DefAnsiEncoding := IndyTextEncoding_OSDefault; // IndyTextEncoding_UTF8
end;

procedure TFK20Elevator.ServerDisconnect(AContext: TIdContext);
begin
  Manager := False;
  Authenticating := False;
  TIdNotify.NotifyMethod(@DisconnectedNotify);
end;

procedure TFK20Elevator.ServerException(AContext: TIdContext; AException: Exception);
begin
  if not (AException is EIdConnClosedGracefully) then
    TMyNotify.NotifyStr(@ErrorNotify, AException.Message);
end;

procedure TFK20Elevator.ServerExecute(AContext: TIdContext);
var
  S, Tmp, UserName, Password: String;
begin
  S := AContext.Connection.IOHandler.ReadLn; //get the data
  if S = Heart then
  begin
    //just a heart beat, return to client and reset timer
    AContext.Connection.IOHandler.WriteLn(Heart);
    TIdNotify.NotifyMethod(@HeartNotify);
    Exit;
  end;

  //not heart beat, decompress
  //EncStr and DecStr simply encode/decode, respectively, a standard
  //  string into/from a key encrypted hex string, i.e. '00' to 'FF'
  //  for each character in the string

  S := PCommon.DecStr(S, EncDecStr, EncDecSIdx);

  if Authenticating then
  begin
    //test log in
    UserName := Fetch(S, '|');
    Password := S;

    if (UserName = ManUser) and (Password = ManPass) then
    begin
      Authenticating := False;
      Manager := True;
      AContext.Connection.IOHandler.WriteLn(EncStr(AContext.Binding.PeerIP + ':' + IntToStr(AContext.Binding.Port) + 'M', EncDecStr, EncDecSIdx));
      TMyNotify.NotifyStr(@ManagerLoggedInNotify, AContext.Binding.PeerIP);
    end
    else if (UserName = GenUser) and (Password = GenPass) then
    begin
      Authenticating := False;
      AContext.Connection.IOHandler.WriteLn(EncStr(AContext.Binding.PeerIP + ':' + IntToStr(AContext.Binding.Port) + 'U', EncDecStr, EncDecSIdx));
      TMyNotify.NotifyStr(@GeneralUserLoggedInNotify, AContext.Binding.PeerIP);
    end else
    begin
      TIdNotify.NotifyMethod(@FailedAuthNotify);
      AContext.Connection.Disconnect;
    end;
    Exit;
  end;

  //test for commands
  if TextStartsWith(S, AssignID) then
  begin
    //command to assign a new unit id

    Tmp := S;
    Fetch(Tmp, '-');
    NewLoc := Fetch(Tmp, '-');
    NewUnit := Tmp;

    if (NewLoc = '') or (NewUnit = '') then
    begin
      NewLoc := DefLocation;
      NewUnit := DefUnitNum;
    end;

    AContext.Connection.IOHandler.WriteLn(PCommon.EncStr(Rebooting, EncDecStr, EncDecSIdx));

    TMyNotify.NotifyStr(@RebootNotify, S + #10 + NewLoc + #10 + NewUnit);
  end;
end;

最后，我建议您考虑从主 UI 线程中删除所有全局变量和心跳/身份验证计时器。在OnExecute 事件本身内部进行超时处理，例如使用客户端的ReadTimeout 属性和/或CheckForDataOnSource() 方法。使用TIdContext.Data 属性（或从TIdServerContext 派生一个新类并将其分配给TIdTCPServer.ContextClass 属性）来跟踪每个连接的值，例如上次接收到心跳的时间，或者客户端是否仍然身份验证（实际上，您应该在OnExecute甚至开始运行之前处理OnConnect中的身份验证），或者客户端是否以管理员身份登录等。这将减少需要与主同步的事情的数量UI 线程，并避免同步处理延迟引入的任何时间问题。

【讨论】：

太好了，谢谢 Remy，我明天会第一时间实施并通知您。
我修改了代码，学到了很多东西，但是我不熟悉使用通知类这样的类，也不知道如何为编译器编写它们，所以当我编译时，它在每个通知过程中告诉我“错误：预期的类标识符”。
@user7475089 你有一个TFK20Elevator 类。您是否在单元的interface 中为该类的声明添加了其他方法？
我使用后在接口下添加了这个：Type TMyNotifyMethod = Procedure(Const AStr: String) Of Object; TMyNotify = Class(TIdNotify) 受保护的 FMethod: TMyNotifyMethod; FStr：字符串；程序DoNotify；覆盖；公共类过程 NotifyStr(AMethod: TMyNotifyMethod; Const AStr: String);结尾; { TFK20Elevator } TFK20Elevator = Class(TForm)
然后这个私有下：Procedure ConnectedNotify(Const APeerIP: String);程序断开通知；过程 ErrorNotify(Const AMessage: String);程序心脏通知；过程 ManagerLoggedInNotify(Const APeerIP: String);过程 GeneralUserLoggedInNotify(Const APeerIP: String);程序FailedAuthNotify；过程重启通知（常量数据：字符串）；