OptionalFieldAttribute OptionalFieldAttribute OptionalFieldAttribute OptionalFieldAttribute Class

定義

指定可從序列化 (Serialization) 資料流中遺漏欄位,使 BinaryFormatterSoapFormatter 不會擲回例外狀況。Specifies that a field can be missing from a serialization stream so that the BinaryFormatter and the SoapFormatter does not throw an exception.

public ref class OptionalFieldAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Field, Inherited=false)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class OptionalFieldAttribute : Attribute
type OptionalFieldAttribute = class
    inherit Attribute
Public NotInheritable Class OptionalFieldAttribute
Inherits Attribute
繼承
OptionalFieldAttributeOptionalFieldAttributeOptionalFieldAttributeOptionalFieldAttribute
屬性

備註

這個屬性可讓您指定新可序列化的型別中的欄位 (型別SerializableAttribute套用至) 會忽略BinaryFormatterSoapFormatterThis attribute allows you to specify that new fields in a serializable type (a type to which the SerializableAttribute is applied to) are ignored by the BinaryFormatter or the SoapFormatter. 這可讓版本相容序列化的序列化資料的應用程式的較舊版本所建立的類型。This enables version-tolerant serialization of types created for older versions of an application that serializes data. 比方說,當格式器遇到不包含新欄位的版本所產生的資料流時,會擲回任何例外狀況,並較舊的型別上的現有資料會以正常方式處理。For example, when the formatters encounter a stream produced by a version that does not include the new fields, no exception is thrown, and the existing data on the older type is processed as normal.

建構函式

OptionalFieldAttribute() OptionalFieldAttribute() OptionalFieldAttribute() OptionalFieldAttribute()

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

屬性

TypeId TypeId TypeId 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.

(Inherited from Attribute)
VersionAdded VersionAdded VersionAdded VersionAdded

取得或設定版本號碼以指出何時新增操作欄位。Gets or sets a version number to indicate when the optional field was added.

方法

Equals(Object) Equals(Object) Equals(Object) 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.

(Inherited from Attribute)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

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

(Inherited from Attribute)
GetType() GetType() GetType() GetType()

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

(Inherited from Object)
IsDefaultAttribute() IsDefaultAttribute() IsDefaultAttribute() 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.

(Inherited from Attribute)
Match(Object) Match(Object) Match(Object) 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.

(Inherited from Attribute)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

建立目前 Object 的淺層複本 (Shallow Copy)。Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

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

(Inherited from Object)

明確介面實作

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

(Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) _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.

(Inherited from Attribute)
_Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _Attribute.GetTypeInfoCount(UInt32) _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).

(Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) _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.

(Inherited from Attribute)

適用於