I have a c# com-interop usercontrol which is hosted inside a vb6 control extender on a vb6 usercontrol. The vb6 control extender has the CausesValidation set to true, but when the hosted com-interop usercontrol loses focus, it is not triggering the Validate on the control extender - I suspect it is because the usercontrol itself never really has focus, but only its nested interop usercontrol.

I've tried issuing the Usercontrol.ValidateControls on LostFocus but although I can see the control extender validate event triggered, it is not raising this event up the event hierarchy to my usercontrol's parent/container control which is what I am needing to do.

Is there a way of manually triggering/raising the Validate event?

Alternatively, is there a windows message which I could post using PostMessage/SendMessage which would achieve the same ends?

Many thx