Question

My Customer Model is as below. Customer Model contains validation attributes

CustomerModel.cs

[IsRequired()]
CustomerID - Int;
[IsRequired()]
CustomerName - String;

CustomerViewModel contains 2 properties as below
1. ObservableCollection of CustomerModel (This is bound Items Source of drop down list)
2. Property returns CustromerModel object as Selected Item (Bound to SelectedItem)

My Question:
How can i provide ValidatesOnDataErrors=true for combo box?

Do i need to write validation attribute on CustomerModel property inside CustomerViewModel?

Please suggest…

Answer 1

IDataErrorInfo is a type specific implementation of Validation (vs. instance specific). You would be better off using ValidationRules. This link should help on how to implement ValidationRules:
http://msdn.microsoft.com/en-us/library/system.windows.data.binding.validationrules.aspx