Loading RTF text from database into TRichEdit

Question

I am currently in the process of migrating our software solution from Delphi 7 to 2010. Mostly the changes have been simple and there are only a small amount of hurdles left

Answer 1

Okay I figured it out.

For loading the rtf text:

//Get the data from the database as AnsiString
rtfString := sql.FieldByName('rtftext').AsAnsiString;

//Write the string into a stream
stream := TMemoryStream.Create;
stream.Clear;
stream.Write(PAnsiChar(rtfString)^, Length(rtfString));
stream.Position := 0;

//Load the stream into the RichEdit
RichEdit.PlainText := False;
RichEdit.Lines.LoadFromStream(stream);

stream.Free;

For saving the rtf text:

//Save to stream
stream := TMemoryStream.Create;
stream.Clear;

RichEdit.Lines.SaveToStream(stream);
stream.Position := 0;

//Read from the stream into an AnsiString (rtfString)
if (stream.Size > 0) then begin
    SetLength(rtfString, stream.Size);
    if (stream.Read(rtfString[1], stream.Size) <= 0) then
        raise EStreamError.CreateFmt('End of stream reached with %d bytes left to read.', [stream.Size]);
end;

stream.Free;

//Save to database
sql.FieldByName('rtftext').AsAnsiString := rtfString;

This took me way too long to figure out :) I guess I have learned one thing though... if something goes wrong in Delphi 2010, its usually related to unicode ;)

Answer 2

When PlainText is False, LoadFromStream() first attempts to load the RTF code, and if that fails then LoadFromStream() attempts to load the stream again as plain text. That has always been the case in all Delphi versions. With the introduction of Unicode, I suppose something could have broken in LoadFromStream()'s EM_STREAMIN callback handler. I suggest you step into LoadFromStream()'s actual source code with the debugger and see what is really happening.