DBLoockupbox möglichkeit kein Auswah zu treffen?

[Peinhard]

Gute Idee, das... Hier ein schnell gestrickter Abkömmling:

Delphi-Quellcode:

unit DBLookupComboBoxEx;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  DB, DBCtrls;

type
  TDBLookupComboBoxEx = class(TDBLookupComboBox)
  private
    FAllowClear: boolean;
    procedure ClearField;
  protected
    procedure KeyDown(var Key: Word; Shift: TShiftState); override;
    procedure MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);  override;
  public
  published
    property AllowClear: boolean read FAllowClear write FAllowClear default False;
  end;

procedure Register;

implementation

procedure TDBLookupComboBoxEx.ClearField;
begin
  if FAllowClear and CanModify then
  begin
    DataSource.Edit;
    Field.Clear;
  end;
end;

procedure TDBLookupComboBoxEx.KeyDown(var Key: Word; Shift: TShiftState);
begin
  inherited KeyDown(Key, Shift);
  if (Key = VK_DELETE) then ClearField;
end;

procedure TDBLookupComboBoxEx.MouseDown(Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  if (Button = mbRight) then ClearField;
  inherited MouseDown(Button, Shift, X, Y);
end;

procedure Register;
begin
  RegisterComponents('DBAddOns', [TDBLookupComboBoxEx]);
end;

end.

Bei Fehlern bitte nicht hauen... Verbesserungen gerne.

Edit: Prozedur ClearField angepasst...

peinhard