CODEWITHSUNDEEP
delphi
SAMPro
SAMPro

Reputation: 1099

Call a procedure(by an event) whose name is set by another procedure

I want a procedure to be executed when an event is happened. But that procedure is set by another procedure(SetNotifierProc).

Firstly I run this: 

SetNotifierProc(Proc1);

And then Proc1 is executed whenever event triggered.

How could I code SetNotifierProc to get a procedure as an argument and how to inform event handler to execute that procedure?

Problem: I have a TCPServerExecute and want to run a procedure to show received data. But because I have multiple forms I want to set a procedure that handle received data.

Thanks

Upvotes: 3

Views: 1005

Answers (2)

LU RD
LU RD

Reputation: 34889

If your procedure is an ordinary procedure without arguments:

Type
  TForm1 = Class(TForm)
    ..
     private

     FMyProc : TProcedure;
   public
     procedure SetEventProc(aProc : TProcedure);
     procedure TheEvent( Sender : TObject);
  end;

procedure Test;
begin
  // Do something
end;

procedure TForm1.SetEventProc(aProc: TProcedure);
begin
  Self.FMyProc := aProc;
end;

procedure TForm1.TheEvent(Sender: TObject);
begin
  if Assigned(FMyProc) then
    FMyProc;
end;

// to set the callback to procedure "Test"
Form1.SetEventProc(Test);

If your procedure has arguments, declare a procedure type:

Type
  MyProcedure = procedure( aString : String);

And if your procedure is a method :

Type
  MyMethod = procedure( aString : String) of Object;

See also documentation about Procedural types.

Upvotes: 3

Andy_D
Andy_D

Reputation: 2350

This should do the trick :-

Type
  TTCPNotifyProc = Procedure(pData : String) Of Object;

TMyTCPServer = Class
Private
  FNotifyProc : TTCPNotifyProc;
..
Public
  Procedure SetNotifier(pProc : TTCPNotifyProc);
End;

Procedure TMyTCPServer.SetNotifier(pProc : TTCPNotifyProc);
Begin
  FNotifyProc := pProc;
End;

Then whenever you need to call the procedure within your server class just call :-

If Assigned(FNotifyProc) Then
  FNotifyProc(DataStringReceived);

Upvotes: 0

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