WPF Data validation on Collection property in Business object

I have a business object with a property defined as such:

    /// <summary>
    /// Gets the Interest Payments dates Collection.
    /// </summary>
    public BindingList<DateTime> InterestPaymentDatesCollection
    {
        get 
        { 
            return this._interestPaymentDatesCollection; 
        }
    }

This is used in a WPF app (I'm an ASP.Net developer that got handed this project) - basically I need to ensure that _interestPaymentDatesCollection has a value set in it - otherwise I need to inform the user that the field is required, etc. Being a WPF newbie I'm unfamiliar with开发者_StackOverflow社区 how to do this. I tried reading the examples on using IDataErrorInfo but couldn't piece together how to do this on a collection property.

Advice appreciated!

Your class that holds the Collection would implement IDataErrorInfo and you would overwrite the this[string.columnName] property with a validation error

There are many ways to implement the validation, but here's a simple example:

public class TestModel : IDataErrorInfo
{
    public List<DateTime> MyCollection {get; set;}

    public string this[string columnName]
    {
        get { return this.GetValidationError(propertyName); }
    }

    public string GetValidationError(string propertyName)
    {
        switch (propertyName)
        {
            case "MyCollection":
                // Do validation here and return a string if an error is found
                if (MyCollection == null) return "Collection not Initialized";
        }
        return null;
    }
}