跳過基於其屬性之一的模型的所有驗證（ASP.Net Core 2.0）

Question

我如何可以跳過基於其屬性之一的模型的所有驗證。 例如，如果對象的WillBeDeleted屬性為 true，驗證器將跳過所有驗證規則。

namespace ViewModel
{
    public class ContactForm : IViewModel
    {
        [ValidateNever]
        public Contact Item { get; set; }

        public Category Category { get; set; }

        [Required, DisplayName("First name")]
        [StringLength(200, ErrorMessage = "First name should not exceed 200 characters.")]
        public string FirstName { get; set; }

        [Required, DisplayName("Last name")]
        [StringLength(200, ErrorMessage = "Last name should not exceed 200 characters.")]
        public string LastName { get; set; }

        public List<TelephonesSubForm> Telephones { get; set; } = new List<TelephonesSubForm>();

        public List<EmailsSubForm> Emails { get; set; } = new List<EmailsSubForm>();

        public class TelephonesSubForm : IViewModel
        {
            public int Id { get; set; }

            public bool MustBeDeleted { get; set; }

            [Required]
            public TelephoneAndEmailType Type { get; set; }

            [Required]
            [StringLength(200, MinimumLength = 10, ErrorMessage = "Telephone should not exceed 200 characters.")]
            public string Telephone { get; set; }
        }

        public class EmailsSubForm
        {
            public int Id { get; set; }

            public bool MustBeDeleted { get; set; }

            [Required]
            public TelephoneAndEmailType Type { get; set; }

            [Required]
            [StringLength(200, MinimumLength = 10, ErrorMessage = "Email should not exceed 200 characters.")]
            public string Email { get; set; }
        }
    }
}

在給定的示例模型中，當MustBeDeleted為true ，表示將在保存操作中刪除電子郵件或電話項。

我搜索並發現了幾個關於條件（自定義）驗證的問題，他們建議在檢查ModelState的驗證狀態之前從ModelState刪除特定的鍵。 像這個。

Answer 1

我正在添加一個新答案並保留舊答案，因為它可能對某人有用

因此，創建一個自定義屬性：

  public class CustomShouldValidateAttribute : Attribute, IPropertyValidationFilter
  {
    public CustomShouldValidateAttribute(){

    }
    public bool ShouldValidateEntry(ValidationEntry entry, ValidationEntry parentEntry)
    {
      //Here you change this verification to Wether it should verificate or not, In this case we are checking if the property is ReadOnly (Only a get method)
      return !entry.Metadata.IsReadOnly;      
    }
  }

和他們在你的班級上你用你的自定義屬性裝飾它

[CustomShouldValidateAttribute]
public class MyClass{
public string Stuff{get;set;}
public string Name {get{return "Furlano";}}
}

Answer 2

盡管這不是問題的完整答案，但可以繼承驗證屬性（ RequiredAttribute 、 StringLength 等）並覆蓋IsValid方法。 作為示例，我提供其中之一。

public class RequiredWhenItIsNotDeletingAttribute : RequiredAttribute
{
    string DeletingProperty;

    /// <summary>
    /// Check if the object is going to be deleted skip the validation.
    /// </summary>
    /// <param name="deletingProperty">The boolean property which shows the object will be deleted.</param>
    public RequiredWhenItIsNotDeletingAttribute(string deletingProperty = "MustBeDeleted") =>
        DeletingProperty = deletingProperty;

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var property = validationContext.ObjectType.GetProperty(DeletingProperty);

        if((bool)property.GetValue(validationContext.ObjectInstance))
            return ValidationResult.Success;

        return base.IsValid(value, validationContext);
    }
}

Answer 3

從 IValidatableObject 繼承您的模型

並實現接口方法：

  public virtual IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {

      if (YourCondition==false){
        yield return new ValidationResult(
          $"This is wrong",
          new[] { nameof(Email) });
      }
      else
         yield return ValidationResult.Success

    }

但是您必須為您的每個屬性實現驗證並排除您已經編寫的裝飾！

Answer 4

您可以調用該方法：

ModelState.Clear()

當 MustBeDeleted 為真時