Indicating a progress

All ECL streams provide a convenient feature allowing developer to display a progress during some potentially slow operations, such as encrypting/decrypting a file, changing compression level, reading and writing a large portion of data, calling LoadFromFile and SaveToFile functions.

To provide user a feedback about the progress of the above operations, you should do the following:

1. Write an event handler that will display the current progress of a process using a progress bar.
2. Assign the above event handler to the ECL stream OnProgress event.

 

The following example shows how to display the current progress while loading and compressing a file.

Example:

procedure TMainForm.CountProgress(Sender: TObject; PercentDone: Real);

begin

ProgressBar.Progress := Round(PercentDone);

Application.ProcessMessages;

end;

 

procedure TMainForm.Button1Click(Sender: TObject);

var

CompFS: TECLFileStream;

begin

{ create compressed file }

CompFS := TECLFileStream.Create('c:\test_comp.ecl', fmCreate, '', ppmMax);

{ assign event handler }

CompFS.OnProgress := CountProgress;

{ load and compress data from test.txt file}

CompFS.LoadFromFile('c:\test.txt');

{ close compressed file }

CompFS.Free;

end;