Question

model validation我需要RequiredIfNull属性。如何添加条件必需属性。条件取决于另一个财产。如果该属性值为null，那么这不应该是。

类似的东西：

public class MyModel
{
    public int? prop1 { get; set; }

    [ConditionalRequired(prop1)]        //if prop1 == null, then prop2 is required, otherwise MyModel is invalid
    public int? prop2 { get; set; }
}

Answer 1

您需要自定义验证属性。例如：

<input type="number" id="myNumber" value="253">
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>

然后在你的模型中：

using System.ComponentModel.DataAnnotations;
using System.Reflection;

    [AttributeUsage(AttributeTargets.Property)]
    public class RequiredIfNullAttribute : ValidationAttribute
    {
        private const string DefaultErrorMessageFormat = "The {0} field is required.";

        public RequiredIfNullAttribute(string otherProperty)
        {
            if (otherProperty == null)
            {
                throw new ArgumentNullException(nameof(otherProperty));
            }

            OtherProperty = otherProperty;
            ErrorMessage = DefaultErrorMessageFormat;
        }

        public string OtherProperty { get; }

        protected override ValidationResult IsValid(object value, 
            ValidationContext validationContext)
        {
            if (value == null)
            {
                var otherProperty = validationContext.ObjectInstance.
                    GetType().GetProperty(OtherProperty);
                object otherPropertyValue = otherProperty.GetValue(
                    validationContext.ObjectInstance, null);

                if (otherPropertyValue == null)
                {
                    return new ValidationResult(
                        string.Format(ErrorMessageString, validationContext.DisplayName));
                }
            }

            return ValidationResult.Success;
        }
    }

如果您还需要添加客户端验证，事情会变得更复杂。

模型验证：RequireIfNull属性（ASP.NET Core）

1 个答案: