Translation Event Handler Description Events Handling Description

Event Handler Description Events Handling Description (custom control)

How should a new event handler is defined if it does not already belong to the base class? Let's look at this using the "Tfrxeditcontrol" common control as an example:

How should a new event handler be defined if it does not belong to the base class? Let's take a look at using the "Tfrxeditcontrol" control as an example:

Tfrxeditcontrol = Class (Tfrxdialogcontrol)

Private

Fedit:tedit;

{New Event}

Fonchange:tfrxnotifyevent; Defines the event, registration type.

Procedure Doonchange (Sender:tobject); Event-handling procedures

...

Public

Constructor Create (aowner:tcomponent); Override

...

Published

{New Event}

Property Onchange:tfrxnotifyevent read Fonchange write Fonchange; Defining events

...

End

Constructor Tfrxeditcontrol.create (aowner:tcomponent);

Begin

...

{Connect Our Handler}

Fedit.onchange: = Doonchange; Associating an event in Create (associating an event of a Tedit control to its own process)

Initcontrol (Fedit);

...

End

Procedure Tfrxeditcontrol.doonchange (Sender:tobject);

Begin

{Call event handler}

If report <> Nil Then

Report.donotifyevent (Sender, Fonchange); Handling events (invoking scripts in the report in the process)

End

It is important to note that the event handler in Fastreport are a procedure defined in the report script. The tfrxnotifyevent type is declared as string[63] and in Fastreport the link to the handler are a String containing its NA Me. This was unlike the Delphi tnotifyevent type, in which it was a method address.

It is important to note that an event handler is a procedure that is defined in a report script. The tfrxnotifyevent type is declared as string[63], and the event-handling process linked in Fastreport is a string (containing its name). This is not like the Tnotifyevent type in Delphi, it is the address of a method.

Translation Event Handler Description Events Handling Description