Today, I am going to tell you about Custom Events on Silverlight 5 controls. Generally when you employ or develop controls the events you employ are a lot of straight forward however this case, we possess a dial therefore the 'mouseover' or click is not actually need you would like. So exactly what we need is once the dial moves to some place we need the 'position changed' event called.

To start out along with you need a few custom event args as we wish to pass the 'angle' from the dial towards the event handler inside the consuming application. Therefore the custom event args appearance such as this:
public class DialEventArgs : EventArgs
{
private double angle;
public DialEventArgs(double _Angle)
{
this.angle = _Angle;
}
public double Angle
{
get
{
return angle;
}
}
}

During this case it is a fairly straight forward class which drives from eventargs so we add a constructor which lets us established the angle property simply. Next we would like in our own control class to outline the event such as this :
public delegate void PositionChangeHandler (Object Sender, DialEventArgs e);
public event PositionChangeHandler PositionChangedEvent;
protected virtual void OnPositionChanged(DialEventArgs e)
{
PositionChangedEvent(this, e);
}

Using this set up a consuming xaml page if they utilize the control can set an event handler for that event. However first we have to truly call the event once the angle in the dial changes : In the method which sets the angle we've this code :
OnPositionChanged(new DialEventArgs(AngleOfRotation));

Currently if you get an event handler set in xaml you will get the event called in the correct time. In xaml this may look such as this:
<cc:Dial x:Name="NewKnobControl" Height="100" Width="100" PositionChangedEvent="NewKnobControl_PositionChangedEvent" Minimum="45.0" Max="135" >
<cc:Dial.KnobFace>
<Grid >
<Ellipse Fill="Aquamarine" />
<Rectangle x:Name="Indicator" Height="10" Width="49" Fill="Blue" Margin="1,45,50,45" />
</Grid>
</cc:Dial.KnobFace>
</cc:Dial>

Now inside the client code you'll need an event handler and during this case inside my demo app it's similar to this :
private void NewKnobControl_PositionChangedEvent(Object sender, DialEventArgs e)
{
// applicable values
double Angle = e.Angle;
}