I could not wait any longer for a reply.  This looks like an unsupported, incomplete (not to mention buggy dev interface that crashes) product.  I purchased Dundas Guage, very powerful and robust.

sorry you couldn't get a response in time.  in the future, if you are using an infragistics product and need a prompt response, please use an official support channel (i.e. Developer Support).  they have a guaranteed response and very quick turnaround, unlike these peer-to-peer forums.

 http://ko.infragistics.com/gethelp

as for needle dragging on linear gauges, this is not yet available as a feature of linear gauges -- radial gauge needles do have an AllowDrag property, but the feature is still not implemented for linear gauges.  you can still achieve this behavior through event handling, though.

This is a unique need.

it is necessary if you want to make needles draggable on a linear gauge.

Does that mean that all the code posted by David Negley is not necessary? 

I will try this today.

Thanks

 the UltraGauge control has a MarkerValueChanged event.

I too was looking for this. I was really hoping to see something along the lines of

needle.ValueChangedHandler += myValueChangedHandler(object sender, ValueChangedEventArgs e );

Any chance to see this in a future version?