Can anyone explain how to register DependencyProperty with an example

The main difference is, that the value of a normal .NET property is read directly from a private member in your class, whereas the value of a DependencyProperty is resolved dynamically when calling the GetValue() method that is inherited from DependencyObject.

When you set a value of a dependency property it is not stored in a field of your object, but in a dictionary of keys and values provided by the base class DependencyObject. The key of an entry is the name of the property and the value is the value you want to set.

Using following way you can register it .

// Dependency Property
public static readonly DependencyProperty CurrentTimeProperty =
     DependencyProperty.Register( "CurrentTime", typeof(DateTime),
     typeof(MyClockControl), new FrameworkPropertyMetadata(DateTime.Now));

// .NET Property wrapper
public DateTime CurrentTime
{
    get { return (DateTime)GetValue(CurrentTimeProperty); }
    set { SetValue(CurrentTimeProperty, value); }
}