Re: Converting standard text to RVF

Author

Message

Sergey Tkachenko

Posted: 05/16/2003 16:00:15

Look at the help topic: "Using viewer-style methods in DBRichViewEdit"

(Example 1 in the topic about TDBRichViewEdit)

In brief, you need to call table.Edit before loading RVF in DBRichViewEdit,

and dbrve.Change after.

Then call table.Post (if you want to save data immediately) or dbrve.Format

(if you want to save them later).

> Sergey,

> By changing to TMemoryStream, the data was successfully changed in the

> TDBRichEdit control, but not saved to the field. The problem still

> remains that any subsequent calls to the word processing form still

> result in an access error. Any other ideas? Since the problem is

> happening in the TRichEdit source I cannot trace to the problem. I do

> know that none of the fonts and sizes are been initialized when the form

> comes up due to the exception in the constructor. I also know that the

> error is trapped in the source since only the debugger's copy of the

> exception comes up.

> Thanks,

> Sean

> Original Messahge:

> Hi,

> I am using the evaluation version of TRichView and am trying to create a

> simple word processor to edit the contents of a TBlobField. I have a

> TDBRichEdit on a form (Edit Form) that displays the contents of the blob

> field which was populated from a simple text memo (TMemoField). On this

> form I have a button which opens a separate word processing form which

> is based on the TRichViewActions demo.

> I am able to load the word processing form with the data from the Edit

> Form and able to pass it back to the Edit Form successfully in a stream.

> I cannot get the streamed data to modify the field underlying the

> TdBRichEdit. To make matters worse, if I make a change to the data in

> the word processing form which results in an unsuccessful change to the

> TDBRichEdit in the EditForm, I get an access error while creating the

> word processing form in every subsequent call, even if it is from a new

> instance of the edit form. The word processor form comes up since this

> error is apparently trapped in the TRichView source code, but the

> TRichViewEdit on that form is in an unstable state with no font or font

> size selected.

> The OnClick method of the button on the Edit Form follows. Note that

> DFEncoded is a TDBRichView, DTLetter is the table, TWordProc is the

> renamed TRichViewActions demo. I used a TStringStream so I could easily

> confirm the stream's contents while debugging.

> procedure TFMLetter.BTWordProcClick(Sender: TObject);

> var

> AStream: TStringStream; {stream to edit data}

> begin

> AStream := TStringStream.Create(''); {use a string stream}

> try

> DFEncoded.SaveRVFToStream(AStream, False); {save to stream}

> if TWordProc.Execute(AStream) then begin {modified?}

> DTLetter.Edit; {put in edit mode}

> AStream.Position := 0; {start of stream}

> DFEncoded.LoadRVFFromStream(AStream); {load from stream}

> DFEncoded.Format; {reformat}

> end; {if modified}

> finally

> AStream.Free; {release stream}

> end; {try-finally}

> end; {procedure}

> The word processing form TWordProc is essentially the TRichViewActions

> demo renamed to TWordProc and with the following class method:

> class function TWordProc.Execute(AStream: TStream): Boolean;

> begin

> with Create(Application) do begin

> try

> Editor.Clear; {clear editor}

> AStream.Position := 0; {start of stream}

> Editor.LoadRVFFromStream(AStream);

> Editor.Format; {format the text}

> ShowModal; {show modal}

> Result := (ModalResult = mrOK); {true if value changed}

> if Result then begin {make changes?}

> AStream.Position := 0; {start of stream}

> Editor.SaveRVFToStream(AStream, False); {save back to stream}

> end; {if changes made}

> finally

> Release; {release form}

> end; {try-finally}

> end; {with the application}

> end; {procedure}

> The other changes:

> 1. The "alternate method" for creating the the form is used so that it

> starts with an empty document instead of trying to open the readme file.

> 2. The close query method no longer asks to save to a file.

> 3. The option to save tags as PChars has been turned off.

> Any ideas what I could be doing wrong here? What is the proper way to

> initialize a TCustomRichEdit so that it is ready to edit text or have it

> copied from some source other than a file.

> Thanks,

> Sean

> Sergey Tkachenko wrote:

> > First idea: do not use TStringStream. It does not work correctly with

binary

> > data.

> > Use TMemoryStream

> >