Loading long RTF-Text in TRichEdit does not work
delphi, delphi-xe4
Solution
Rich edit control has a text limit.
Try using `EM_EXLIMITTEXT` message, which sets an upper limit to the amount of text the user can type or paste into a rich edit control. This message also limit the amount of text that you can stream into a rich edit control when streaming RTF (`PlainText = False`). but does not limit the control when streaming plain text.
e.g.:
const
RE_MAX_TEXT_SIZE = 256000;
SendMessage(RichEdit1.Handle, EM_EXLIMITTEXT, 0, RE_MAX_TEXT_SIZE);
or:
SendMessage(RichEdit1.Handle, EM_EXLIMITTEXT, 0, $7FFFFFF0);
for the maximum limit as implemented in `TRichEditStrings.LoadFromFile()`: `RichEdit.DoSetMaxLength($7FFFFFF0);` However, `DoSetMaxLength()` is not correctly used in the sources, as it should be called before the stream is loaded. Also, `DoSetMaxLength()` is not used at all for `TRichEditStrings.LoadFromStream()`. Remy mentioned this in the comments of his answers.
Problem
If a long RTF-sequenz (eg 150 000 chars) is streamed into a `TRichEdit` control (in XE4), the control does not display the text but instead shows the raw RTF code: ``` {\rtf1\ansi\ansicpg1252\deff0... ``` What is wrong? ``` procedure TForm1.Button1Click(Sender: TObject); var RtfText: string; Stream: TStringStream; begin RtfText := GenerateRtfText(); Stream := TStringStream.Create(RtfText); try RichEdit2.PlainText := False; RichEdit2.Lines.LoadFromStream(Stream); //<--- ERROR: RichEdit displays raw RTF-Code // if RtfText is too long if StartsText('{\rtf', RichEdit2.Lines.Text) then begin ShowMessage('Oh no, not converted!'); //WORKAROUND: 2nd try seems to work... //Stream.Position := 0; //RichEdit2.Lines.LoadFromStream(Stream); end; finally Stream.Free; end; end; ``` For instance with following RTF generation function: ``` function TForm1.GenerateRtfText: string; var I: Integer; Stream: TStringStream; const DOES_WORK_COUNT = 10000; DOES_NOT_WORK_COUNT = 15000; begin //Fill RichEdit1.Lines.BeginUpdate; try //for I := 0 to DOES_WORK_COUNT do for I := 0 to DOES_NOT_WORK_COUNT do RichEdit1.Lines.Add(IntToStr(I)); finally RichEdit1.Lines.EndUpdate; end; //Convert to RTF Stream := TStringStream.Create; try RichEdit1.Lines.SaveToStream(Stream); Result := Stream.DataString; finally Stream.Free; end; end; ``` Edited: Even copy and paste does not work correctly: This is what I did: - I copied the generated content of RichEdit1 (lines 1..15000 with numbers 1..15000) into notpad.exe to remove any RTF - I copied the content of notepad into RichEdit2 Result: - only 12773 lines are displayed correctly. The last line is only `12` - if I try to add another char into the TRichEdit nothing happens - if I remove 10 chars (per backspace) I can add exactly 10 chars afterwards... Is there a hidden character limit for TRichEdit?