[C#]	public event WPFViewPortEventHandler ViewPortChanged;
[VB]	Public Event ViewPortChanged As WPFViewPortEventHandler

This event occurs when the viewport is changed through mouse actions, or when WPFChartViewer.updateViewPort is called.

WPFViewPortEventHandler is a delegate representing the signature of the method that can be used to handle viewport changed events. It is declared as follows.

[VB]	Public Delegate Sub WPFViewPortEventHandler(sender As Object, e As WPFViewPortEventArgs)
[C#]	public delegate void WPFViewPortEventHandler(object sender, WPFViewPortEventArgs e);

In the above, "sender" is the object that raises the event, and "e" is a WPFViewPortEventArgs object that contains the event data.