Look for specified sequence in stream

[Bummi]

If the filesize is not to big, you could use a MemoryStream and POS

Delphi-Quellcode:

var
  ms: TMemoryStream;
begin
  ms := TMemoryStream.Create;
  try
    ms.LoadFromFile('C:\temp\Logger1.png');
    Caption := IntToStr(Pos(RawByteString(#$89#$50), RawByteString(ms.Memory)));
    // Caption := IntToStr(Pos(RawByteString('PNG'),RawByteString(ms.Memory)))
  finally
    ms.Free;
  end;
end;