Memo, je nach Bedarf 1-3 Zeilen groß. Wie? [VCL]

[Uwe Raabe]

Vielleicht so (sicher noch optimierbar):

Delphi-Quellcode:

type
  TMemoHelper = class helper for TMemo
  public
    procedure AdjustHeight(MaxLines: Integer);
  end;

procedure TMemoHelper.AdjustHeight(MaxLines: Integer);
var
  border: Integer;
  DC: HDC;
  metrics: TTextMetric;
  S: string;
  saveFont: HFont;
  size: TSize;
  sysMetrics: TTextMetric;
  W: Integer;
begin
  WordWrap := false;

  DC := GetDC(0);
  try
    GetTextMetrics(DC, sysMetrics);
    saveFont := SelectObject(DC, Font.Handle);
    GetTextMetrics(DC, metrics);
    W := 0;
    for S in Lines do begin
      GetTextExtentPoint32(DC, S, Length(S), size);
      W := Max(W, size.cx);
    end;
    SelectObject(DC, saveFont);
  finally
    ReleaseDC(0, DC);
  end;
  if NewStyleControls then begin
    border := GetSystemMetrics(SM_CYBORDER) * IfThen(Ctl3D, 8, 6);
  end
  else begin
    border := Min(sysMetrics.tmHeight, metrics.tmHeight) div 4 + GetSystemMetrics(SM_CYBORDER) * 4;
  end;

  if Lines.Count > MaxLines then begin
    ScrollBars := ssVertical;
    W := W + GetSystemMetrics(SM_CXVSCROLL);
  end
  else begin
    ScrollBars := ssNone;
  end;
  Height := MaxLines * metrics.tmHeight + border;
  Width := W + border;
end;