checkbox validation does not work about aspnet-client-validation HOT 3 CLOSED

    public class InputModel
    {
        [Required] // <- added this
        public bool IsChecked { get; set; }
    }

public class ContactFormModel
{
    [Required]
    public string Name { get; set; }        
    [Required]
    public string Email { get; set; }
    [Required]
    public string Message { get; set; }
    [EnforceTrue]  // notice this custom dataattribute
    public bool AcceptTerms { get; set; }

    public string Phone { get; set; }
}

public class EnforceTrueAttribute : ValidationAttribute, IClientModelValidator
{
    public override bool IsValid(object value)
    {
        if (value == null) return false;
        if (value.GetType() != typeof(bool)) throw new InvalidOperationException("can only be used on boolean properties.");
        return (bool)value;
    }

    public void AddValidation(ClientModelValidationContext context)
    {
        MergeAttribute(context.Attributes, "data-val", "true");
        MergeAttribute(context.Attributes, "data-val-enforcetrue", "this is required");
    }

    private void MergeAttribute(IDictionary<string, string> attributes,
        string key,
        string value)
    {
        if (attributes.ContainsKey(key))
        {
            return;
        }
        attributes.Add(key, value);
    }
}