type
  TRichEditHotFix = class(TRichEdit)
  private
  protected
    procedure CreateParams(var Params: TCreateParams);override;
  end;

implementation

{ TRichEditHotFix }

procedure TRichEditHotFix.CreateParams(var Params: TCreateParams);
const
  WordWraps: array[Boolean] of DWORD = (0,
    ES_AUTOHSCROLL or WS_HSCROLL);
begin
  inherited;
  // 修复WordWrap=True时没有自动换行的问题（WIN10以前的版本应该不存在该问题）
  with Params do
    Style := Style and not WordWraps[WordWrap];
end;

procedure TForm1.ChangeWordWrap();
begin
  RichEdit1.WordWrap := not RichEdit1.WordWrap;
  if RichEdit1.WordWrap then
    RichEdit1.ScrollBars := TScrollStyle.ssVertical
  else
    RichEdit1.ScrollBars := TScrollStyle.ssBoth;
end;