How do I uncheck all radio buttons at one time?

To uncheck all RadioButton controls at once! Since RadioButton controls are designed to be mutually exclusive within a group (like in your GroupBox), you might need to manually set each RadioButton to IsChecked = false.

Here’s how you can do that in your xaml.cs file:

// Assuming this is part of a method in your code-behind
foreach (var child in FirstGroupBox.Children)
{
    if (child is RadioButton rb)
    {
        rb.IsChecked = false;// Uncheck each RadioButton
    }
}