Fórum Backup com ProgressBar #321895

FUNCTION TFormPrin.DoCopyFile(const SrcFile, DstFile: string; var progresso: TGauge): Boolean;
const
  bufSize = 50000;
var
  sStream,
  dStream : TFileStream;
  pBuf    : Pointer;
  cnt     : Integer;
  cnt2    : Integer;
  totCnt, strmSize: Int64;
begin
  Result := True;
  fPararCopia := False;
  totCnt := 0;

  try
    sStream := TFileStream.Create(SrcFile, fmOpenRead or fmShareDenyWrite);
  except on E: Exception do begin
        Result := False;
        Exit;
     end;
  end;

{  progresso.Visible := sStream.Size > ((1.5 * 1024) * 1024); // Maior que 1.5Mb}
  Progresso.MinValue := 0;
  Progresso.MaxValue := 100;
  Progresso.Progress := 0;

  strmSize := sStream.size;

   try  
     try 
        dStream := TFileStream.Create(DstFile, fmCreate or fmShareExclusive);
     except on E: Exception do begin
           Result := False;
           Exit;
        end;
     end; 

     try 
       GetMem(pBuf, bufSize);
       try 
         cnt := sStream.Read(pBuf^, bufSize);
         cnt := dStream.Write(pBuf^, cnt);

         totCnt := totCnt + cnt;
         while (cnt > 0) do begin
           If fPararCopia then
              Break;
           cnt := sStream.Read(pBuf^, bufSize);
           cnt2:= dStream.Write(pBuf^, cnt);

           if cnt2 <> cnt then
              Result := False;

           cnt := cnt2;

           totcnt := totcnt + cnt;
           progresso.Progress := Round((totCnt / strmSize) * 100);
           Application.ProcessMessages;
         end;

       finally
         FreeMem(pBuf, bufSize);
       end;
     finally
       dStream.Free;
       if fPararCopia then       {Se cancelar entao deleta o arquivo}
         DeleteFile(PChar(DstFile));
     end; 
   finally
     sStream.Free;
   end; 
end;