EnumDataTypeAttribute 類別

定義

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

Object

Attribute

ValidationAttribute

DataTypeAttribute

EnumDataTypeAttribute

屬性

AttributeUsageAttribute

範例

以下範例說明如何將列舉的數值替換為對應的宣告。

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

這個類別讓你可以將欄位中的底層值映射到對應的列舉常數名稱。 這讓你可以定義一個包含描述性值的枚舉，這些值對應於資料庫值，然後在顯示資料時使用枚舉常數名稱取代資料庫值。