我在Delphi中使用弹出菜单.我希望以“无线电组”的方式使用它,如果用户选择了一个项目,则检查它并且不检查其他项目.我尝试使用Autocheck属性,但这允许检查多个项目.有没有办法设置弹出菜单,以便只能检查一个项目?
解决方法
Zartog是正确的,但是如果要保留复选框,请将此事件分配给弹出菜单中的每个项目.
请注意,此代码有点毛茸茸,因为它不依赖于知道弹出菜单的名称(因此,使用“GetParentComponent”查找).
procedure TForm2.OnPopupItemClick(Sender: TObject); var i : integer; begin with (Sender as TMenuItem) do begin //if they just checked something... if Checked then begin //go through the list and *un* check everything *else* for i := 0 to (GetParentComponent as TPopupMenu).Items.Count - 1 do begin if i <> MenuIndex then begin //don't uncheck the one they just clicked! (GetParentComponent as TPopupMenu).Items[i].Checked := False; end; //if not the one they just clicked end; //for each item in the popup end; //if we checked something end; //with end;
您可以在运行时将事件分配给表单上的每个弹出框(如果您想这样做):
procedure TForm2.FormCreate(Sender: TObject); var i,j: integer; begin inherited; //look for any popup menus,and assign our custom checkBox handler to them if Sender is TForm then begin with (Sender as TForm) do begin for i := 0 to ComponentCount - 1 do begin if (Components[i] is TPopupMenu) then begin for j := 0 to (Components[i] as TPopupMenu).Items.Count - 1 do begin (Components[i] as TPopupMenu).Items[j].OnClick := OnPopupItemClick; end; //for every item in the popup list we found end; //if we found a popup list end; //for every component on the form end; //with the form end; //if we are looking at a form end;
回答此答案下方的评论:如果您要求至少检查一个项目,请使用此项目代替第一个代码块.您可能希望在oncreate事件中设置默认选中的项目.
procedure TForm2.OnPopupItemClick(Sender: TObject); var i : integer; begin with (Sender as TMenuItem) do begin //go through the list and make sure *only* the clicked item is checked for i := 0 to (GetParentComponent as TPopupMenu).Items.Count - 1 do begin (GetParentComponent as TPopupMenu).Items[i].Checked := (i = MenuIndex); end; //for each item in the popup end; //with end;