Title: How to change the OnClick behavior of a TRadioButton, TCombobox
procedure ChangeRadiobuttonState(ARadiobutton: TRadiobutton;
checkit: Boolean);
var
oldhandler: TNotifyEvent;
begin
oldhandler := ARadiobutton.Onclick;
ARadiobutton.Onclick := nil;
ARadiobutton.Checked := checkit;
ARadiobutton.OnClick := oldhandler;
end;
// To make the combobox "click" after setting the item index simply call its
// Click method. The control inherits this method from TControl, but it is
// protected. So you need a bit of hoop-jumping:
Type
TComboCracker = class(TCombobox);
procedure SetComboboxIndex(ACombobox: TCombobox; Index: Integer);
begin
ACombobox.ItemIndex := Index;
TCombocracker(ACombobox).Click;
end;