What's the proper way to read which RadioButton is checked in C#? [duplicate]

Question

I was wondering if there's any proper way of reading RadioButton that's checked from one GroupBox. So far I would create something along this lines per each GroupBox.

    private int checkRadioButton() {
        if (radioButtonKwartal1.Checked) {
            return 1;
        } else if (radioButtonKwartal2.Checked) {
            return 2;
        } else if (radioButtonKwartal3.Checked) {
            return 3;
        } else if (radioButtonKwartal4.Checked) {
            return 4;
        }
        return 0;

    }

Edit: there are some preety good answers but knowing which radioButton is pressed is one thing, but knowing the return value attached to it is 2nd. How can I achieve that? The code above lets me get return values which then I can use later in a program.

Answer 1

You can use LINQ

var checkedButton = container.Controls.OfType<RadioButton>().Where(r => r.IsChecked == true).FirstOrDefault();

This assumes that you have 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.

Otherwise, you could make List<RadioButton>s in your constructor for each group, then write list.FirstOrDefault(r => r.Checked)

Which Radio button in the group is checked?