Question

I’m creating a custom RadioButton that has some additional functionality. I need to somehow subscribe to an “OnDataBound” event – is there such a way to do this?

Thanks!

Answer 1

The simplest way i can think of:

1) Create a UserControl that encapsulates a RadioButton with a DependencyProperty that holds a CustomIsChecked object:

/// <summary>
    /// Interaction logic for CustomRadioButton.xaml
    /// </summary>
    public partial class CustomRadioButton : UserControl
    {
        public CustomRadioButton()
        {
            InitializeComponent();
            this.DataContext = this;
        }

        #region CustomIsChecked
        public bool CustomIsChecked
        {
            get { return (bool)GetValue(CustomDataContextProperty); }
            set { SetValue(CustomDataContextProperty, value); }
        }

        // Using a DependencyProperty as the backing store for CustomIsChecked.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty CustomIsCheckedProperty =
            DependencyProperty.Register("CustomIsChecked", typeof(bool), typeof(CustomRadioButton), new UIPropertyMetadata(new PropertyChangedCallback((dpo, dpce) => 
            {
                MessageBox.Show("IsChecked has changed!");
            })));
        #endregion
    }

In the XAML part of the UserControl, bind the IsChecked of your RadioButton to the CustomIsChecked:

<UserControl x:Class="WpfApplication1.CustomRadioButton"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <RadioButton IsChecked="{Binding CustomIsChecked, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=UserControl}}" />
</UserControl>

voila!