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mr2

Registriert seit: 3. Mai 2003
140 Beiträge
 
Delphi 2006 Enterprise
 
#2

Re: Meine erste Kompo: Problem mit dem Changeereignis

  Alt 22. Mär 2004, 20:28
Hallo,

Du brauchst natürlich einen Setter für die Property Value.

mr2
Delphi-Quellcode:
 TIntegerComponent = class(TComponent)
  private
    FValue: Integer; // besser Integer nehmen & alles was mit 'F' beginnt immer private lassen!
    FOnValueChange: TValueChangeEvent;
    procedure SetValue(NewValue: Integer);
    { Private-Deklarationen }  // diese Kommentare sollten immer am Ende eines Blocks stehen
  published
    property OnValueChange: TValueChangeEvent read FOnValueChange write FOnValueChange;
    property Value: Integer read FValue write SetValue;
    { Published-Deklarationen }
  end;

procedure TIntegerComponent.SetValue(NewValue: Integer);
begin
  if (NewValue <> FValue)
  then begin
    if Assigned(FOnValueChange)
    then FOnValueChange(Self, FValue);
    FValue := NewValue;
  end;
end;
"... we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we don't know. But there are also unknown unknowns - the ones we don't know we don't know."
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