hi,

i'm using the dbisam v 4.22(b6) with BCB5. I need to store-work with
wideStrings,
which field type can i use best?? bytes, blob? in version 4 manual
wideString aren't mentioned.
Now i'm trying with bytes-type, i can read-write my wideString! But if i
connect a DBGrid with
wideString support( TntWare) to the dbisam table it dont work correcty....

any suggestion?

Davide.

Davide,

<< I need to store-work with wideStrings, which field type can i use best?? bytes, blob? >>

I don't have experience of BCB, only Delphi 6+7 with DBISAM ver 3 and Tnt Unicode controls.
But I have successfully stored and retrieved widestring data in a blob field. We got truncation
trying to read byte-by-byte because you often trip over chr(0) as part of a Unicode character.
So we defined a packed record which can be read either as two chars or as one widechar
(i.e. as a Unicode character).

The packed record and the retrieval procedure to load a Tnt memo are shown below.

Cheers,
Dan

Lexicon Software Ltd, Bath, UK


type
 TMyConvert = packed record
 Case IsWide : Boolean of
 True : (WChar :WideChar);
 False : (Chars : Array [0..1] of char);
 end;

procedure TEditorForm.ShowAsianTextInUnicodeControl(DictTable: TDBISAMTable;
 DictFieldname: string; UnicodeControl: TTntMemo);
var
 CharCount : integer;
 MyBlob : TBlobField;
 MemStream : TMemoryStream;
 WString : WideString;
 MyConvert : TMyConvert;
begin
 MyBlob := TBlobField(TDBISAMTable(DictTable).FieldByName(DictFieldname));
 if (MyBlob.BlobSize > 0) then
 begin
   MemStream := TMemoryStream.Create;
   MyBlob.SaveToStream(MemStream);
   MemStream.Position := 0;

   for CharCount := 1 to MemStream.Size do
   begin
     if (CharCount mod 2) = 0 then
     begin
       MemStream.ReadBuffer(MyConvert.Chars,2);
       WString := WString + MyConvert.WChar;
     end;
   end;
   UnicodeControl.Text := WString;
 end
 else
   UnicodeControl.Text := '';
end;