How to copy a RTF string to the clipboard in delphi 2009?

Question

Here is my code that was working in Delphi pre 2009? It just either ends up throwing up a heap error on SetAsHandle. If I change it to use AnsiString as per original, i.e.

procedure RTFtoClipboard(txt: string; rtf: AnsiString);

and

Data := GlobalAlloc(GHND or GMEM_SHARE, Length(rtf)*SizeOf(AnsiChar) + 1);

then there is no error but the clipboard is empty.

Full code:

unit uClipbrd;

interface

procedure RTFtoClipboard(txt: string; rtf: string);

implementation

uses
  Clipbrd, Windows, SysUtils, uStdDialogs;
VAR
  CF_RTF : Word = 0;

//------------------------------------------------------------------------------
procedure RTFtoClipboard(txt: string; rtf: string);
var
  Data: Cardinal;
begin
  with Clipboard do
  begin
    Data := GlobalAlloc(GHND or GMEM_SHARE, Length(rtf)*SizeOf(Char) + 1);
    if Data <> 0 then
      try
        StrPCopy(GlobalLock(Data), rtf);
        GlobalUnlock(Data);
        Open;
        try
          AsText := txt;
          SetAsHandle(CF_RTF, Data);
        finally
          Close;
        end;
      except
        GlobalFree(Data);
        ErrorDlg('Unable to copy the selected RTF text');
      end
    else
      ErrorDlg('Global Alloc failed during Copy to Clipboard!');
  end;
end;

initialization
  CF_RTF := RegisterClipboardFormat('Rich Text Format');
  if CF_RTF = 0 then
    raise Exception.Create('Unable to register the Rich Text clipboard format!');
end.

Answer 1

To quote Wikipedia:

RTF is an 8-bit format. That would limit it to ASCII, but RTF can encode characters beyond ASCII by escape sequences. The character escapes are of two types: code page escapes and Unicode escapes. In a code page escape, two hexadecimal digits following an apostrophe are used for denoting a character taken from a Windows code page. For example, if control codes specifying Windows-1256 are present, the sequence \'c8 will encode the Arabic letter beh (ب).

If a Unicode escape is required, the control word \u is used, followed by a 16-bit signed decimal integer giving the Unicode codepoint number. For the benefit of programs without Unicode support, this must be followed by the nearest representation of this character in the specified code page. For example, \u1576? would give the Arabic letter beh, specifying that older programs which do not have Unicode support should render it as a question mark instead.

So your idea of using AnsiString is good, but you would also need to replace all characters that are not ASCII and are not part of the current Ansi Windows codepage with the Unicode escapes. This should ideally be another function. Your code to write the data to the clipboard could remain the same, with the only change to use the Ansi string type.