How to handle Booleans/CheckBoxes in ASP.NET MVC 2 with DataAnnotations?

Question

I\'ve got a view model like this:

public class SignUpViewModel
{
    [Required(ErrorMessage = \"Bitte lesen und akzeptieren Sie die AGB.\")]
    [DisplayName         


        

Answer 1

My Solution is as follows (it's not much different to the answers already submitted, but I believe it's named better):

/// 

/// Validation attribute that demands that a boolean value must be true.
/// 
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = false)]
public class MustBeTrueAttribute : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        return value != null && value is bool && (bool)value;
    }
}

Then you can use it like this in your model:

[MustBeTrue(ErrorMessage = "You must accept the terms and conditions")]
[DisplayName("Accept terms and conditions")]
public bool AcceptsTerms { get; set; }