Hi, We are using Microsoft Unity and we are using dependency injection and so we have parametrised constructor. So now how to call such a usercontrol in the main window. I see the below error when i added the usercontrol in xaml. "It does not define a public parameterless constructor or a type converter" I have added the usercontrol in XAML as below xmlns:usrRefundArrivalProcessor="Ttl.Refunds.Wpf.Dashboad.Application.Usercontrols;assembly=Ttl.Refunds.Wpf.Dashboad.Application"