有没有比使用Entity Framework + IDataErrorInfo更好的方法来实现模型验证？

Question

Currently, I have this :

• Generated model partial class by entity framework
• My own partial class of this entity implementing the IDataErrorInfo interface

This works, however : is there anyway I can move the generic code to some other class? What's the best approach? We (before moving to Entity Framework) used to have an "Entity" class and a Poco. This entity class extend from some base class where interfaces where implemented like IDataErrorInfo . Because the other part of the partial class already extends from EntityObject, I cannot use this approach, but I feel stupid writing every partial class again 80% the same code. The only "real" difference would be the logic of the Validate method.

public partial class Customer : IDataErrorInfo, ICustomer
{
    private readonly IDictionary<string, string> _errors = new Dictionary<string, string>();

    public Customer()
    {
        base.
        PropertyChanged += Model_PropertyChanged;
    }

    private void Model_PropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        Validate();
    }

    private void Validate()
    {
        if (Name != null && Name.Equals("Banana"))
        {
            this[GetPropertyName(() => Name)] = "Some really nice error here";
        }
    }

    #region "IDataErrorInfo"

    public virtual string this[string columnName]
    {
        get
        {
            if (_errors.ContainsKey(columnName))
            {
                return _errors[columnName];
            }
            return null;
        }
        protected set
        {
            if (value == null && _errors.ContainsKey(columnName))
            {
                _errors.Remove(columnName);
            }
            else
            {
                if (_errors.ContainsKey(columnName))
                    _errors[columnName] = value;
                else
                    _errors.Add(columnName, value);
            }
        }
    }

    public virtual string Error
    {
        get
        {
            if (_errors.Values.Count > 0)
            {
                return _errors.Values.First();
            }
            return null;
        }
    }
    #endregion

    public static string GetPropertyName<T>(Expression<Func<T>> expression)
    {
        MemberExpression body = (MemberExpression)expression.Body;
        return body.Member.Name;
    }
}

Answer 1

您可以使用IValidatableobject请参阅http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.ivalidatableobject.aspx