How do I get which radio button is checked from a groupbox?

Question

I have these groupboxes:

I want to run some code according to checked

Answer 1

You can find all checked RadioButtons like

var buttons = this.Controls.OfType<RadioButton>()
                           .FirstOrDefault(n => n.Checked);

Also take a look at CheckedChanged event.

Occurs when the value of the Checked property changes.

Answer 2

Rather than checking all RadioButtons, use the Validated event of the GroupBox.

private void grpBox_Validated(object sender, EventArgs e)
    {
        GroupBox g = sender as GroupBox;
        var a = from RadioButton r in g.Controls where r.Checked == true select r.Name;
        strchecked = a.First();
     }

Answer 3

groupbox1.Controls.OfType<RadioButton>().FirstOrDefault(r => r.Checked).Name

this will get the name of checked radio button. If you want to use it later, you might store name of that by storing into variable.

Cheers

Answer 4

You should take some look at the CheckedChanged event to register the corresponding event handler and store the Checked radio button state in some variable. However, I would like to use LINQ here just because you have just some RadioButtons which makes the cost of looping acceptable:

var checkedRadio = new []{groupBox1, groupBox2}
                   .SelectMany(g=>g.Controls.OfType<RadioButton>()
                                            .Where(r=>r.Checked))
// Print name
foreach(var c in checkedRadio)
   System.Diagnostics.Debug.Print(c.Name);

Answer 5

In my opinion, it's better if you use RadioGroup instead of GroupBox. If you use radioGroup, you can always find the selected item easily like this:

radioGroup.selectedIndex;

If you design using Windows Forms, I suggest to implement RadioGroup behavior like this (please note that my code is in Java):

for (Component comp:groupBox1.components) {
    if (((RadioButton)comp).selected)
        return ((RadioButton)comp).value;
}

You can put this code block in a method to return selected radioButton value, and then you can use this value in your SWITCH part.