Collection-Property

Dezember 2, 2008 - Lesezeit: 3 Minuten

eine Collection-Property mit Editor erstellen, ohne das diese im Objektinspektor sichtbar ist...

Property public definieren

  public
    property SeriesList: TCollection read FSeriesList write SetSeriesList;
  end;

Property für Speichern/Laden anmelden

  private
    procedure ReadSeries(Reader: TReader);
    procedure WriteSeries(Writer: TWriter);
  protected
    procedure DefineProperties(Filer: TFiler); override;
    ...

procedure TdspExtChart.ReadSeries(Reader: TReader);
begin
  SeriesList.Clear;
  Reader.ReadValue;
  Reader.ReadCollection(SeriesList);
end;

procedure TdspExtChart.WriteSeries(Writer: TWriter);
begin
  Writer.WriteCollection(FSeriesList);
end;

procedure TdspExtChart.DefineProperties(Filer: TFiler);
begin
  inherited;
  Filer.DefineProperty('SeriesList', ReadSeries, WriteSeries, True);
end;

Editor für die Eigenschaft erstellen

uses Classes,dspChart,DesignEditors,DesignIntf,ColnEdit;

// Package designide70 für ColnEdit einfügen !!!

type
  TDspChartEditor = class(TComponentEditor)
  public
    procedure ExecuteVerb(Index: Integer); override;
    function GetVerb(Index: Integer): string; override;
    function GetVerbCount: Integer; override;
  end;

procedure Register;
begin
  RegisterComponents('Dsp', [TdspExtChart]);
  RegisterComponentEditor(TdspExtChart,TDspChartEditor);
end;

{ TDspChartEditor }
procedure TDspChartEditor.ExecuteVerb(Index: Integer);
begin
  if Index=0 then
    ShowCollectionEditor(Designer, Component,
   (Component as TdspExtChart).SeriesList, 'SerienList')
  else
    inherited ExecuteVerb(Index-1);
end;

function TDspChartEditor.GetVerb(Index: Integer): string;
begin
  if Index=0 then
    Result:='Serien bearbeiten'
  else
    Result:=inherited GetVerb(Index-1);
end;

function TDspChartEditor.GetVerbCount: Integer;
begin
  Result:= inherited GetVerbCount+1;
end;

verbesserte Routine zum Speichern, das in der Vererbung von Formularen gleiche Property's nur einmal gespeichert werden

procedure TdspExtChart.DefineProperties(Filer: TFiler);
var
  StoreIt: boolean;
  Chart2: TdspExtChart;
begin
  inherited;
  Chart2 := Filer.Ancestor as TdspExtChart;
  if Chart2 = nil then // keine Vererbung
    StoreIt := true // immer Speichern
  else              // Coll. vergleichen
    StoreIt := not CollectionsEqual(
      FSeriesList, Chart2.FSeriesList, self, Chart2);
  Filer.DefineProperty('SeriesList', ReadSeries, WriteSeries, StoreIt);
end;

Tags: Delphi