Setting TRadioButton to checked causes OnClick event

Question

mybox.Checked := true;

Setting TRadioButton to checked (by code) causes OnClick event handler to be called.

How can I recognize if user is

Answer 1

 mybox.Tag := 666; 
 mybox.Checked :=true; 
 mybox.Tag := 0;

procedure myboxOnclick(Sender : TObject);
begin
if Tag = 0 then
//Do your thing
end;

Answer 2

If you have an action connected to the radiobutton, you can set the checked property of the action instead. This will also prevent the OnClick event to be fired.

Answer 3

TRadioButton (like TCheckBox) provides a protected property ClicksDisabled that can help you.

I use class helpers to add the needed functionality:

RadioButton1.SetCheckedWithoutClick(False);

with the following class helper for a VCL TRadioButton:

TRadioButtonHelper = class helper for TRadioButton
    procedure SetCheckedWithoutClick(AChecked: Boolean);
end;

procedure TRadioButtonHelper.SetCheckedWithoutClick(AChecked: Boolean);
begin
    ClicksDisabled := True;
    try
        Checked := AChecked;
    finally
        ClicksDisabled := False;
    end;
end;

Answer 4

You can nil the OnClick event handler while changing a radiobutton state programmatically:

procedure TForm1.Button6Click(Sender: TObject);
var
  Save: TNotifyEvent;

begin
  Save:= RadioButton2.OnClick;
  RadioButton2.OnClick:= nil;
  RadioButton2.Checked:= not RadioButton2.Checked;
  RadioButton2.OnClick:= Save;
end;