Web API自定义验证,以根据已批准值列表检查字符串

Question

我想验证Web API REST命令的输入.我希望它能够像State下面那样使用限制参数有效值的属性进行修饰.

public class Item {
    ...

    // I want State to only be one of "New", "Used", or "Unknown"
    [Required]
    [ValidValues({"New", "Used", "Unknown"})]
    public string State { get; set; }

    [Required]
    public string Description { get; set; }

    ...
}

有没有办法在不违背Web API的情况下做到这一点.理想情况下,该方法类似于Ruby on Rails的自定义验证.

Answer 1

创建从中派生ValidationAttribute并覆盖IsValid成员函数的自定义验证属性.

public class ValidValuesAttribute: ValidationAttribute
{
  string[] _args;

  public ValidValuesAttribute(params string[] args)
  {
    _args = args;
  }

  protected override ValidationResult IsValid(object value, ValidationContext validationContext)
  {
    if (_args.Contains((string)value))
      return ValidationResult.Success;
    return new ValidationResult("Invalid value.");
  }
}

那你可以做

[ValidValues("New", "Used", "Unknown")]

上述代码尚未编译或测试.