The Delay and Interval properties make a RepeatButton
different than a normal button.
A RepeatButton is a button that fires Click events repeatedly when it is
pressed and held. The rate and aspects of repeating are determined by the Delay and Interval properties that the control exposes.
The code snippet in Listing 3 sets the Delay and Interval
properties.
<RepeatButton Margin="10,10,0,0"
VerticalAlignment="Top"
HorizontalAlignment="Left"
Name="GrowButton"
Width="80" Height="30"
Delay="500" Interval="100"
>
Grow
</RepeatButton>