ProgressBar aus Klasse bedienen

[Union]

Zitat von SirThornberry:

oder eben mit der Callbackvariante

Delphi-Quellcode:

  TProgressEvnt = procedure(Sender: TObject; Progress: Integer) of Object;
  TComplexDataObject = class(TObject) 
  private 
    fOnProgress: TProgressEvnt;
  published
    property OnProgress: TProgressEvnt read fOnProgress write fOnProgress;
  end;
[...]
procedure TComplexDateObject.DeineBerechnung;
begin
  //Do something
  if Assigned(fOnProgress) then
    fOnProgress(Self, x);
  //Do something
end;

Ich halte das mit dem Callback auch für am sinnvollsten und flexibelsten. Das Beispiel stammt aus einer Klasse, die Datenstrukturen aus SAP einliest:

Delphi-Quellcode:

// Notify-Event for reading/writing of IDocs
TIDocProgressEvent = procedure(iStepBy, iMax: integer) of object;
...
property OnReadFromFile : TIDocProgressEvent read FOnReadFromFile write SetOnReadFromFile;
...
// Call notification for startup
if assigned(FOnReadFromFile) then
   FOnReadFromFile(-1, iFileSize);
...
// Call progress function
if assigned(FOnReadFromFile) then
   FOnReadFromFile(FilePosition-OldFilePosition,-1);
...

// Handler which is called while processing the input file
IDoc.OnReadFromFile := IDocFileProgress;


//------------------------------------------------------------------------------
procedure TfrmMain.IDocFileProgress(iStepBy, iMax: integer);
//------------------------------------------------------------------------------
// Notification which is called while processing the IDOC
// iStepBy : < 0 = Start
//           > 0 = Number of lines processed in this step
//------------------------------------------------------------------------------
begin
   if iStepBy < 0 then begin
      ProgressBar1.Properties.Max := iMax;
      ProgressBar1.Properties.Min := 0;
      ProgressBar1.Position := 0;
   end
   else
      Progressbar1.Position := ProgressBar1.Position+iStepBy;

end;