Copy HTML to Clipboard

uses ExtCtrls, ComCtrls

//

{
  If youve ever tried sticking html into the clipboard using the usual CF_TEXT
  format then you might have been disappointed to discover that wysiwyg html
  editors paste your offering as if it were just text,
  rather than recognising it as html. For that you need the CF_HTML format.
  CF_HTML is entirely text format and uses the transformation format UTF-8.
  It includes a description, a context, and within the context, the fragment.

  As you may know one can place multiple items of data onto the clipboard for
  a single clipboard entry, which means that the same data can be pasted in a
  variety of different formats in order to cope with target
  applications of varying sophistocation.

  The following example shows how to stick CF_TEXT (and CF_HTML)
  into the clipboard.
}
function FormatHTMLClipboardHeader(HTMLText: string): string;
const
  CrLf = #13#10;
begin
  Result := 'Version:0.9' + CrLf;
  Result := Result + 'StartHTML:-1' + CrLf;
  Result := Result + 'EndHTML:-1' + CrLf;
  Result := Result + 'StartFragment:000081' + CrLf;
  Result := Result + 'EndFragment:°°°°°°' + CrLf;
  Result := Result + HTMLText + CrLf;
  Result := StringReplace(Result, '°°°°°°', Format('%.6d', [Length(Result)]), []);
end;

//The second parameter is optional and is put into the clipboard as CF_HTML.
//Function can be used standalone or in conjunction with the VCL clipboard so long as
//you use the USEVCLCLIPBOARD conditional define
//($define USEVCLCLIPBOARD}
//(and clipboard.open, clipboard.close).
//Code from http://www.lorriman.com
procedure CopyHTMLToClipBoard(const str: string; const htmlStr: string = '');
var
  gMem: HGLOBAL;
  lp: PChar;
  Strings: array[0..1] of string;
  Formats: array[0..1] of UINT;
  i: Integer;
begin
  gMem := 0;
  {$IFNDEF USEVCLCLIPBOARD}
  Win32Check(OpenClipBoard(0));
  {$ENDIF}
  try
    //most descriptive first as per api docs
    Strings[0] := FormatHTMLClipboardHeader(htmlStr);
    Strings[1] := str;
    Formats[0] := RegisterClipboardFormat('HTML Format');
    Formats[1] := CF_TEXT;
    {$IFNDEF USEVCLCLIPBOARD}
    Win32Check(EmptyClipBoard);
    {$ENDIF}
    for i := 0 to High(Strings) do
    begin
      if Strings[i] = '' then Continue;
      //an extra "1" for the null terminator
      gMem := GlobalAlloc(GMEM_DDESHARE + GMEM_MOVEABLE, Length(Strings[i]) + 1);
      {Succeeded, now read the stream contents into the memory the pointer points at}
      try
        Win32Check(gmem <> 0);
        lp := GlobalLock(gMem);
        Win32Check(lp <> nil);
        CopyMemory(lp, PChar(Strings[i]), Length(Strings[i]) + 1);
      finally
        GlobalUnlock(gMem);
      end;
      Win32Check(gmem <> 0);
      SetClipboardData(Formats[i], gMEm);
      Win32Check(gmem <> 0);
      gmem := 0;
    end;
  finally
    {$IFNDEF USEVCLCLIPBOARD}
    Win32Check(CloseClipBoard);
    {$ENDIF}
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  CopyHTMLToClipBoard(RichEdit1.Text);
end;