如何将条件必需属性放入类属性中以与 WEB API 一起使用？

我只想放条件必需属性这是与WEB API

Example

public sealed class EmployeeModel
{
      [Required]
      public int CategoryId{ get; set; }
      public string Email{ get; set; } // If CategoryId == 1 then it is required
}

我正在通过（动作过滤器属性)

您可以自己实现ValidationAttribute。也许是这样的：

public class RequireWhenCategoryAttribute : ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var employee = (EmployeeModel) validationContext.ObjectInstance;
        if (employee.CategoryId == 1)
            return ValidationResult.Success;

        var emailStr = value as string;
        return string.IsNullOrWhiteSpace(emailStr)
            ? new ValidationResult("Value is required.")
            : ValidationResult.Success;
    }
}

public sealed class EmployeeModel
{
    [Required]
    public int CategoryId { get; set; }
    [RequireWhenCategory]
    public string Email { get; set; } // If CategoryId == 1 then it is required
}

这只是一个示例。它可能存在铸造问题，我不确定这是解决此问题的最佳方法。