Which Radio button in the group is checked?

Billy picture Billy · Nov 25, 2009 · Viewed 310.8k times · Source

Using WinForms; Is there a better way to find the checked RadioButton for a group? It seems to me that the code below should not be necessary. When you check a different RadioButton then it knows which one to uncheck… so it should know which is checked. How do I pull that information without doing a lot of if statements (or a switch).

     RadioButton rb = null;

     if (m_RadioButton1.Checked == true)
     {
        rb = m_RadioButton1;
     }
     else if (m_RadioButton2.Checked == true)
     {
        rb = m_RadioButton2;
     }
     else if (m_RadioButton3.Checked == true)
     {
        rb = m_RadioButton3;
     }

Answer

SLaks picture SLaks · Nov 25, 2009

You could use LINQ:

var checkedButton = container.Controls.OfType<RadioButton>()
                                      .FirstOrDefault(r => r.Checked);

Note that this requires that all of the radio buttons be directly in the same container (eg, Panel or Form), and that there is only one group in the container. If that is not the case, you could make List<RadioButton>s in your constructor for each group, then write list.FirstOrDefault(r => r.Checked).