DataMemberAttribute Class
When applied to the member of a type, specifies that the member is part of a data contract and is serializable by the DataContractSerializer.
Assembly: System.Runtime.Serialization (in System.Runtime.Serialization.dll)
The DataMemberAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() | EmitDefaultValue | Gets or sets a value that specifies whether to serialize the default value for a field or property being serialized. |
![]() ![]() | IsRequired | Gets or sets a value that instructs the serialization engine that the member must be present when reading or deserializing. |
![]() ![]() | Name | Gets or sets a data member name. |
![]() ![]() | Order | Gets or sets the order of serialization and deserialization of a member. |
![]() | TypeId | When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.) |
| Name | Description | |
|---|---|---|
![]() ![]() | Equals | Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.) |
![]() ![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() ![]() | GetHashCode | Returns the hash code for this instance. (Inherited from Attribute.) |
![]() ![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | IsDefaultAttribute | 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 | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.) |
![]() ![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() ![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | _Attribute.GetIDsOfNames | Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.) |
![]() ![]() | _Attribute.GetTypeInfo | Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.) |
![]() ![]() | _Attribute.GetTypeInfoCount | Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.) |
![]() ![]() | _Attribute.Invoke | Provides access to properties and methods exposed by an object. (Inherited from Attribute.) |
Apply the DataMemberAttribute attribute in conjunction with the DataContractAttribute to identify members of a type that are part of a data contract. One of the serializers that can serialize data contracts is the DataContractSerializer.
The data contract model is an "opt-in" model. Applying the DataMemberAttribute to a field or property explicitly specifies that the member value will be serialized. In contrast, the BinaryFormatter serializes public and private fields of a type, and the XmlSerializer serializes only public fields and properties of a type.
Caution |
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You can apply the DataMemberAttribute to private fields or properties. Be aware that the data returned by the member (even if it private) will be serialized and deserialized, and thus can be viewed or intercepted by a malicious user or process. |
By default, the CLR member name is used as the name of the data member. By setting the Name property, you can customize the name of the data member. This can be used to provide a name that may not be allowed as a CLR member name. When mapping to XML using the DataContractSerializer, this name is used as the name of the schema element in a type.
Note |
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Properties to which the DataMemberAttribute attribute has been applied must have both get and set fields; they cannot be get-only or set-only. |
For more information about data contracts and data members, see Using Data Contracts. For more information about member names, see Data Member Default Values.
The following example shows two types to which the DataContractAttribute and DataMemberAttribute attributes have been applied. The Name property is set to "Customer".
Imports System.Collections Imports System.IO Imports System.Runtime.Serialization Imports System.Xml ' You must apply a DataContractAttribute or SerializableAttribute ' to a class to have it serialized by the DataContractSerializer. <DataContract()> _ Class Person Implements IExtensibleDataObject Private LastNameValue As String ' Apply the DataMemberAttribute to fields (or properties) ' that must be serialized. <DataMember()> _ Public FirstName As String <DataMember()> _ Public Property LastName() As String Get Return LastNameValue End Get Set(ByVal Value As String) LastNameValue = Value End Set End Property <DataMember(Name:="ID")> _ Public IdNumber As Integer ' Note that you can apply the DataMemberAttribute to ' a private field as well. <DataMember()> _ Private Secret As String Public Sub New(ByVal newfName As String, ByVal newLName As String, ByVal newIdNumber As Integer) FirstName = newfName LastName = newLName IdNumber = newIdNumber Secret = newfName + newLName + newIdNumber.ToString() End Sub ' The ExtensionData field holds data from future versions ' of the type. This enables this type to be compatible with ' future versions. The field is required to implement the ' IExtensibleObjectData interface. Private extensionDataValue As ExtensionDataObject Public Property ExtensionData() As ExtensionDataObject _ Implements IExtensibleDataObject.ExtensionData Get Return extensionDataValue End Get Set extensionDataValue = value End Set End Property End Class Public Class Test Public Shared Sub Main(ByVal args() As String) Try ReadObject("DataMemberAttributeExample.xml") WriteObject("DataMemberAttributeExample.xml") Catch exc As Exception Console.WriteLine("The serialization operation failed: {0} StackTrace: {1}", _ exc.Message, exc.StackTrace) Finally Console.WriteLine("Press <Enter> to exit....") Console.ReadLine() End Try End Sub Public Shared Sub ReadObject(ByVal filename As String) ' Create a new instance of the Person class. Dim p1 As New Person("Zighetti", "Barbara", 101) Dim writer As New FileStream(filename, FileMode.Create) Dim ser As New DataContractSerializer(GetType(Person)) ser.WriteObject(writer, p1) writer.Close() End Sub Public Shared Sub WriteObject(ByVal filename As String) ' Deserialize an instance of the Person class ' from an XML file. Dim fs As New FileStream(filename, FileMode.OpenOrCreate) Dim ser As New DataContractSerializer(getTYpe(Person)) ' Deserialize the data and read it from the instance. Dim deserializedPerson As Person = ser.ReadObject(fs) fs.Close() Console.WriteLine(String.Format("{0} {1}, ID: {2}", _ deserializedPerson.FirstName, deserializedPerson.LastName, deserializedPerson.IdNumber)) End Sub End Class
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.






Caution
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