Event Handler in Delphi

[FaNIX]

How do i set the event for a specific class event?

This is how it looks in VB.NET

Delphi-Quellcode:

        AddHandler FtpClient.MessageReceive, AddressOf FtpClient_MessageReceive
        AddHandler FtpClient.MessageSend, AddressOf FtpClient_MessageSend

Below is the hand coded event i want to assign to the class:

Delphi-Quellcode:

procedure FtpClient_Feedback(Sender : TObject; E : TKFP.Net.MessageArgs);

Here is the declaration of the class event:


http://img136.imageshack.us/img136/3082/29591014oc2.jpg

The following doesnt work:

Delphi-Quellcode:

 Fo_FtpClient.MessageReceive := FtpClient_Feedback;

I get the following errors:
[Pascal Error] u_fdn_FTP_Dot_Net.pas(93): E2298 read/write not allowed for CLR events. Use Include/Exclude procedure
[Pascal Error] u_fdn_FTP_Dot_Net.pas(93): E2035 Not enough actual parameters

[edit=Phoenix]Marked as a .NET topic. Mfg, Phoenix[/edit]

[DP-Maintenance]

Dieses Thema wurde von "Phoenix" von "Programmieren allgemein" nach "Object-Pascal / Delphi-Language" verschoben.
Delphi-Question -> Delphi board

[sirius]

One problem could be that your Ftp_client_feedback is a simple procedure and the property Messagerecieve waits for a "procedure of object" (a method within a class)

[Phoenix]

Nope. As the compiler says: In Delphi.NET you must use the Include/Exclude functions to add/delete Eventhandler. That's because in CLR you always have multicast delegates (you can add more than one handler to a single event at a given time), and Delphi does not know the += / -= syntax to add / remove a single handler from an event. So you have to use

Delphi-Quellcode:

Include(Event, Eventhandler);

or

Delphi-Quellcode:

Exclude(Event, Eventhandler);

instead of

Delphi-Quellcode:

Event := handler;

.
If you can understand a bit of german, then have a look at this excellent article from Sakura: http://www.delphipraxis.net/internal...=248261#248261