Setting TRadioButton to checked causes OnClick event

mybox.Checked := true;
开发者_高级运维

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

How can I recognize if user is making the state change by GUI interaction

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;

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

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

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.

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;