The easiest way would be to update the bindingexpression for each property which will force validation to occur. A bit of a hack but saves you having to have your validation rules duplicated from your entity setter.

This hack will loop through all children of an element and force validation. You could make this more generic but this should give you the idea of how to make it happen. Additionally you could throw in a call to Validation.GetErrors(uiElement) after bindingExpression.UpdateSource which will return any validation errors on the element. Handy if you want to manage your errors centrally with some other control etc.

        ForceValidation(LayoutRoot.Children);

        private void ForceValidation(IEnumerable uiElements)
        {
            foreach (var uiElement in uiElements)
            {
                BindingExpression bindingExpression = null;
                
                switch (uiElement.GetType().ToString())
                {
                    case "System.Windows.Controls.StackPanel":
                    case "System.Windows.Controls.Panel":
                        ForceValidation(((Panel)uiElement).Children);
                        break;

                    case "System.Windows.Controls.TextBox":
                        bindingExpression = ((TextBox)uiElement).GetBindingExpression(TextBox.TextProperty);
                        break;

                    case "System.Windows.Controls.RadioButton":
                        bindingExpression = ((RadioButton)uiElement).GetBindingExpression(ToggleButton.IsCheckedProperty);
                        break;
                }

                if (bindingExpression == null || bindingExpression.ParentBinding == null) continue;
                if (!bindingExpression.ParentBinding.ValidatesOnExceptions) continue;

                bindingExpression.UpdateSource();
            }
        }

Regards,

S