Question

I have a form that containts 2 groupbox, each groupbox contain a radiobutton call radioButton1 (tab index:0) and radioButton2 (tab index: 1).

At the first run, the radioButton1 will be checked and the other is not, when I press Tab on keyboard, the focus will jump to radiobutton (see the picture above, it’s really good), but when I checked the radiobButton2 then press Tab, the focus not jump to radioButton1, why is that? Here is my method when checked the radioButton2:

private void radioButton2_CheckedChanged(object sender, EventArgs e)
    {
        radioButton1.Checked = false;
    }

Answer 1

Clearing the checked property is clearing the tabstop property on your radio button.

Resetting it will fix the problem:

  private void radioButton2_CheckedChanged( object sender, EventArgs e )
  {
     radioButton1.Checked = false;
     radioButton1.TabStop = true;
  }