[Lazarus] TFileStream

[Michael Van Canneyt]

On Thu, 29 Jan 2009, Dave Coventry wrote:

> ============= snip ===================
>    case ftype of
>      43://'+'
>      begin
>        FS:=TFileStream.Create(fname, fmshareDenyWrite);
>        Try
>          FS.Seek(pos,soFromBeginning);
>          FS.ReadBuffer(fldheader[0],4);
>          increm:=LEtoN(PLongInt(fldheader)^)+1;
>          for m:=0 to 3 do
>          begin
>            fldheader[m]:=increm and 255;
>            increm:=increm shr 8;
>          end;
>           FS.Seek(pos,soFromBeginning);
>           FS.WriteBuffer(fldheader[0],4); <----- Fails here
>        Finally
>          FreeAndNil(FS);
>        end;
>      end;
>    end;
> ============= snip ===================
> 
> Continuing on the same block:
> 
> I am trying to read a block of 4 bytes, increment it by one and write
> it back again.
> 
> However, if fails on the write.

Probably because you failed to specify fmOpenReadWrite.
fmshareDenyWrite does not automatically mean write access.

Michael.

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