Broken TBytes

[wil32]

Delphi-Quellcode:

procedure WhyIsItNotWorking;
var
Stream : TBytesStream;
b : TBytes ;
begin
Stream := TBytesStream.Create;
Stream.LoadFromFile( AttachedPDF );

b := Stream.Bytes ;

Stream := TBytesStream.Create( b );
Stream.SaveToFile( AttachedPDF + '2' );

FreeAndNil(Stream);
end;

2nd file is corrupted. there is a bunch of wrong bytes at the end of the file. if you notepad the 2nd pdf and remove said bytes. everything is normal

http://rghost.net/private/67PGPC8QF/...ccaf86fec0bb41

this is a form/fillable pdf

above code works with 'regular' pdf

[Dejan Vu]

Please format your code using the Delphi tags.

Edit your post, select your Code and press that little helmet button.
This will surround your Code with [ CODE="Delphi"] [ /CODE] Tags.

Then save.

[Klaus01]

Hi,
your TBytes Array doesn't have a defined size.

May this will help:

Delphi-Quellcode:

setlength(b,stream.size);
stream.ReadBuffer(b,stream.size);

Cheers Klaus

[Der schöne Günther]

Just use the debugger to inspect your b: TBytes after you've done your b := Stream.Bytes; .

It already contains more bytes than your original file. Since the Bytes property just reads out an ordinary field, something must have gone wrong in LoadFromFile .

The root cause is the protected method Realloc of TMemoryStream , the parent of your TBytesStream . It makes sure the internal byte array is always aligned to a multiple of 8KB.

This way, the Byte property is garbage, you will have to truncate it afterwards, just as Klaus already said:

Delphi-Quellcode:

procedure WhyIsItNotWorking();
const
   path = 'x:\cake.pdf';
var
   Stream : TBytesStream;
   b : TBytes ;
begin
   Stream := TBytesStream.Create();
   Stream.LoadFromFile(path);

   b := Stream.Bytes;
   SetLength(b, Stream.Size); // This is new

   Stream := TBytesStream.Create(b);
   Stream.SaveToFile( path.Replace('cake', 'cake2') );

   FreeAndNil(Stream); // You know that you did not destroy the first TStream instance?
end;

I would have made the same mistake. I don't think this was to be expected.

[Sir Rufo]

It is documented and works as designed:

Zitat:

The Bytes property returns the buffer in which the data is stored. Use the Size property to find the actual amount of data in the buffer.

(taken from http://docwiki.embarcadero.com/Libra...esStream.Bytes)

[wil32]

Thanks everyone. Please note that the 'issue' didn't happen on android

[Sir Rufo]

Zitat von wil32:

Thanks everyone. Please note that the 'issue' didn't happen on android

You should note, that there is no issue at all