TCollection und TCollectionItem

[Jens Schumann]

@maximov:
Was sagst Du dazu?

Delphi-Quellcode:

unit CollectionExt;

interface

Uses SysUtils, Classes;

Type

  TJsCollection = class(TCollection)
  private
    FCollectionname : String;
    FIntValue       : Integer;
    function GetFormatSignature: String;
  public
    procedure SaveToFile(const Filename : TFilename);
    procedure SaveToStream(Stream : TStream);
    procedure LoadFromFile(const Filename : TFilename);
    procedure LoadFromStream(Stream : TStream);
  published
    property Collectionname : String read FCollectionname write FCollectionname;
    property IntValue        : Integer read FIntValue write FIntValue;
  end;

  TWriterExt = class(TWriter)
  public
    procedure WriteCollection(Value: TCollection);
    procedure WriteCollectionProperties(Value : TCollection);
  end;

  TReaderExt = class(TReader)
  public
    procedure ReadCollection(Value: TCollection);
    procedure ReadCollectionProperties(Value: TCollection);
  end;


implementation

uses TypInfo;

const
  iFilerBufferSize = 4096;

{ TJsCollection }

function TJsCollection.GetFormatSignature: String;
begin                             
  Result := ItemClass.ClassName;
end;

procedure TJsCollection.LoadFromFile(const Filename: TFilename);
var
  FileStream : TFileStream;
begin
  Clear;
  FileStream:=TFileStream.Create(Filename,fmOpenRead);
  Try
    LoadFromStream(FileStream);
  Finally
    FileStream.Free;
    end;
end;

procedure TJsCollection.LoadFromStream(Stream: TStream);
var
  Reader  : TReaderExt;
begin
  Reader:=TReaderExt.Create(Stream,iFilerBufferSize);
  Try
    Reader.ReadCollection(Self);
  Finally
    Reader.Free;
    end;
end;

procedure TJsCollection.SaveToFile(const Filename: TFilename);
var
  FileStream : TFileStream;
begin
  FileStream:=TFileStream.Create(Filename,fmCreate);
  Try
    SaveToStream(FileStream);
  Finally
    FileStream.Free;
    end;
end;

procedure TJsCollection.SaveToStream(Stream: TStream);
var
  Writer       : TWriterExt;
begin
  Writer:=TWriterExt.Create(Stream,iFilerBufferSize);
  Try
    Writer.WriteCollection(Self);
  Finally
    Writer.Free;
    end;
end;

{ TWriterExt }

procedure TWriterExt.WriteCollection(Value: TCollection);
begin
  WriteCollectionProperties(Value);
  inherited WriteCollection(Value);
end;

procedure TWriterExt.WriteCollectionProperties(Value: TCollection);
begin
  WriteProperties(Value);
end;

{ TReaderExt }

procedure TReaderExt.ReadCollection(Value: TCollection);
begin
  ReadCollectionProperties(Value);
  ReadValue;
  inherited ReadCollection(Value);
end;

procedure TReaderExt.ReadCollectionProperties(Value: TCollection);
var
  PropList   : TPropList;
  PropCount  : Integer;
  iCnt       : Integer;
begin
  PropCount:=GetPropList(Value.ClassInfo,tkProperties,@PropList);
  For iCnt:=0 to PropCount-1 do
    ReadProperty(Value);
end;

end.

Entpacke mal die Anlage, starte die EXE, klicke ein paar mal auf Add, dann auf Save und zum Schluss auf Load.

[Edit]Habe gerade noch ein bisschen rumgetestet. Auch die properties von SubCollections (wenn ein TCollectionItem eine TCollection enthält) werden gestreamt[/Edit]