EnumDataTypeAttribute 類別

定義

讓 .NET 列舉對應至資料行。Enables a .NET enumeration to be mapped to a data column.

public ref class EnumDataTypeAttribute sealed : System::ComponentModel::DataAnnotations::DataTypeAttribute
[System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Method | System.AttributeTargets.Parameter | System.AttributeTargets.Property, AllowMultiple=false)]
public sealed class EnumDataTypeAttribute : System.ComponentModel.DataAnnotations.DataTypeAttribute
[<System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Method | System.AttributeTargets.Parameter | System.AttributeTargets.Property, AllowMultiple=false)>]
type EnumDataTypeAttribute = class
    inherit DataTypeAttribute
Public NotInheritable Class EnumDataTypeAttribute
Inherits DataTypeAttribute
繼承
屬性

範例

下列範例將示範如何使用對應的宣告來取代列舉值的數值。The following example shows how to replace the numeric value of an enumeration with the corresponding declaration.

public enum ReorderLevel
{
    Zero = 0,
    Five = 5,
    Ten = 10,
    Fifteen = 15,
    Twenty = 20,
    TwentyFive = 25,
    Thirty = 30
}

[MetadataType(typeof(ProductMD))]  
public partial class Product
{  
    public class ProductMD
    {  
        [EnumDataType(typeof(ReorderLevel))]  
        public object ReorderLevel { get; set; }  
    }  
}  
Imports Public Enum eReorderLvl  
    zero = 0  
    five = 5  
    ten = 10  
    fifteen = 15  
    twenty = 20  
    twenty_five = 25  
    thirty = 30  
End Enum  
<MetadataType(GetType(Product_MD))>  _  
Public Class Product  
    Public Class Product_MD  
        <EnumDataType(GetType(eReorderLvl))>  _  
        Public Property ReorderLevel As Object  
        End Property  
    End Class  
End Class  

備註

這個類別可讓您將資料行中的基礎值對應到相對應的列舉常數名稱。This class lets you map the underlying value in a column to a corresponding enumeration constant name. 這可讓您定義列舉,其中包含對應至資料庫值的描述性值,然後在顯示資料時使用列舉常數名稱,而不是資料庫值。This lets you define an enumeration that contains descriptive values that correspond to database values, and then use the enumeration constant names instead of the database values when data is displayed.

建構函式

EnumDataTypeAttribute(Type)

初始化 EnumDataTypeAttribute 類別的新執行個體。Initializes a new instance of the EnumDataTypeAttribute class.

屬性

CustomDataType

取得與資料欄位相關聯的自訂欄位範本名稱。Gets the name of custom field template that is associated with the data field.

(繼承來源 DataTypeAttribute)
DataType

取得與資料欄位相關聯的型別。Gets the type that is associated with the data field.

(繼承來源 DataTypeAttribute)
DisplayFormat

取得資料欄位的顯示格式。Gets a data-field display format.

(繼承來源 DataTypeAttribute)
EnumType

取得或設定列舉型別。Gets or sets the enumeration type.

ErrorMessage

取得或設定錯誤訊息,此錯誤訊息會在驗證失敗時與驗證控制項產生關聯。Gets or sets an error message to associate with a validation control if validation fails.

(繼承來源 ValidationAttribute)
ErrorMessageResourceName

取得或設定要在驗證失敗時用來查閱 ErrorMessageResourceType 屬性值的錯誤訊息資源名稱。Gets or sets the error message resource name to use in order to look up the ErrorMessageResourceType property value if validation fails.

(繼承來源 ValidationAttribute)
ErrorMessageResourceType

取得或設定資源類型,此類型可在驗證失敗時用於查閱錯誤訊息。Gets or sets the resource type to use for error-message lookup if validation fails.

(繼承來源 ValidationAttribute)
ErrorMessageString

取得當地語系化的驗證錯誤訊息。Gets the localized validation error message.

(繼承來源 ValidationAttribute)
RequiresValidationContext

取得值,這個值表示屬性是否需要驗證內容。Gets a value that indicates whether the attribute requires validation context.

(繼承來源 ValidationAttribute)
TypeId

在衍生類別中實作時,取得這個 Attribute 的唯一識別碼。When implemented in a derived class, gets a unique identifier for this Attribute.

(繼承來源 Attribute)

方法

Equals(Object)

傳回值,這個值指出此執行個體是否與指定的物件相等。Returns a value that indicates whether this instance is equal to a specified object.

(繼承來源 Attribute)
FormatErrorMessage(String)

根據發生錯誤所在的資料欄位,將格式套用至錯誤訊息。Applies formatting to an error message, based on the data field where the error occurred.

(繼承來源 ValidationAttribute)
GetDataTypeName()

傳回與資料欄位相關聯的型別名稱。Returns the name of the type that is associated with the data field.

(繼承來源 DataTypeAttribute)
GetHashCode()

傳回這個執行個體的雜湊碼。Returns the hash code for this instance.

(繼承來源 Attribute)
GetType()

取得目前執行個體的 TypeGets the Type of the current instance.

(繼承來源 Object)
GetValidationResult(Object, ValidationContext)

檢查指定的值在目前的驗證屬性方面是否有效。Checks whether the specified value is valid with respect to the current validation attribute.

(繼承來源 ValidationAttribute)
IsDefaultAttribute()

在衍生類別中覆寫時,表示這個執行個體的值是衍生類別的預設值。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(繼承來源 Attribute)
IsValid(Object)

檢查資料欄位的值是否有效。Checks that the value of the data field is valid.

IsValid(Object, ValidationContext)

根據目前的驗證屬性,驗證指定的值。Validates the specified value with respect to the current validation attribute.

(繼承來源 ValidationAttribute)
Match(Object)

在衍生類別中覆寫時,會傳回值,表示這個執行個體是否等於指定物件。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(繼承來源 Attribute)
MemberwiseClone()

建立目前 Object 的淺層複製。Creates a shallow copy of the current Object.

(繼承來源 Object)
ToString()

傳回代表目前物件的字串。Returns a string that represents the current object.

(繼承來源 Object)
Validate(Object, String)

驗證指定的物件。Validates the specified object.

(繼承來源 ValidationAttribute)
Validate(Object, ValidationContext)

驗證指定的物件。Validates the specified object.

(繼承來源 ValidationAttribute)

明確介面實作

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

將一組名稱對應至一組對應的分派識別項 (Dispatch Identifier)。Maps a set of names to a corresponding set of dispatch identifiers.

(繼承來源 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

擷取物件的類型資訊,可以用來取得介面的類型資訊。Retrieves the type information for an object, which can be used to get the type information for an interface.

(繼承來源 Attribute)
_Attribute.GetTypeInfoCount(UInt32)

擷取物件提供的類型資訊介面數目 (0 或 1)。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(繼承來源 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

提供物件所公開的屬性和方法的存取權。Provides access to properties and methods exposed by an object.

(繼承來源 Attribute)

適用於