How to pack file using 7z with Delphi and show percent done?

Question

When I run this from command line:

7z a 1.zip J:\test.mp4

I can see how much in % is done. When I tried to run this from Delphi using CreateProcess and CreatePipe I got nothing until the file is packed. Then it displayed the final output from 7zip.

My code looks like this:

Stream:= THandleStream.Create(hRead);
try
  if not CreateProcess(nil, PChar(Cmd), nil, nil, 
                       True, 0, nil, nil, StartupInfo, 
                       ProcessInformation) then
    RaiseLastOSError;
  repeat
    if not GetExitCodeProcess(ProcessInformation.hProcess, ExitCode) then
      RaiseLastOSError;

    while Stream.Position < Stream.Size do 
    begin
      Stream.Read(C, 1);

      if (C = #13) then 
      begin
        Memo1.Lines.Add(S);
        S := '';
        Application.ProcessMessages;
      end
      else if C <> #10 then 
      begin
        S := S+C;
      end;
    end;
  until ExitCode <> Still_Active;
finally
  Stream.Free;
end;

I don't want to just create a ZIP archive- I know there are nicer ways to do this in Delphi. I want to interact with a console applications. Output from many console applications can be processed with the code I posted, but it fails with 7zip- that's why I ask about 7zip here. What is so special about 7zip that its output can't be captured properly? How to capture output from applications like this 7zip?

Answer 1

You can take a look at the plugin made by progdigy

Progress bar

 function ProgressCallback(sender: Pointer; total: boolean; value: int64): HRESULT; stdcall;
 begin
   if total then
     Mainform.ProgressBar.Max := value else
     Mainform.ProgressBar.Position := value;
   Result := S_OK;
 end;

 procedure TMainForm.ExtractClick(Sender: TObject);
 begin
   with CreateInArchive(CLSID_CFormatZip) do
   begin
     OpenFile('c:\test.zip');
     SetProgressCallback(nil, ProgressCallback);
     ...
   end;
 end;