wpf - XamDateTimeEditor spin button click set focus -

i using xamdatetimeeditor time (hh:mm) masking. when cursor focus in control works on spin button , down.but cursor focus in other control , click on spin button (up or down) nothing happened. how can set focus in current control when click on spin button (up or down).

i believe same question answered in infragistics' forums:

http://www.infragistics.com/community/forums/t/79746.aspx