WPF: in custom UserControl, create custom DependencyProperty, where you can bind some value to.

MyUserControl.xaml.cs

public partial class MyUserControl : UserControl
{
    // The dependency property definition.
    public static readonly DependencyProperty MyStateProperty =
        DependencyProperty.Register
        (
            "MyState", // Name of dependency property.
            typeof(string), // Type of dependency property.
            typeof(MyUserControl), // Type of the class who owns the dependency property.
            new FrameworkPropertyMetadata
            (
                string.Empty, // Default value of dependency property.
                OnMyStatePropertyChanged // Callback function when dependency property is changed.
            )
        );

    // Getter and setter for dependency property.
    public string MyState
    {
        get { return (string)GetValue(MyStateProperty); }
        set { SetValue(MyStateProperty, value); }
    }

    // Callback function to handle the change of dependency property.
    public static void OnMyStatePropertyChanged
    (
        DependencyObject d, // i.e. owner of the dependency property.
        DependencyPropertyChangedEventArgs e // Event arguments.
    )
    {
        var control = (MyUserControl)d;

        /* Do something for that */
    }

    /* Other things for MyUserControl */
}

It's wrong as to use GetValue and Setvalue we need to inhert the class from DependencyObject class but MyUserControl is already inherited from UserControl.So GetValue is not available.Please resolve this problem.