如何更改属性错误消息

Question

我重写了RequiredAttribute,在我的IsValid方法中,我需要能够更改ErrorMessage属性.这可能吗？

Answer 1

[Required(ErrorMessage = "Some custom required message about the Foo property")]
public string Foo { get; set; }

并在IsValid方法内:

public class MyRequiredAttribute : RequiredAttribute
{
    public override bool IsValid(object value)
    {
        ErrorMessage = "Some custom required message";
        ...
        return base.IsValid(value);
    }
}