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)
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.
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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.
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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, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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