mahapps.metro

ProgressRing

The Progress Ring control is styled after a similar control in Windows 8 to indicate activity rather than a percentage of progress completed.

<Controls:ProgressRing IsActive="True" />

IsActive can easily be bound to a viewmodel property.

<Controls:ProgressRing IsActive="{Binding IsActive}" />

Override Foreground if you wish to change the colour.

<Controls:ProgressRing Foreground="{DynamicResource AccentColorBrush}"/>