OnDeserializedAttribute Class
When applied to a method, specifies that the method is called immediately after deserialization of an object in an object graph. The order of deserialization relative to other objects in the graph is non-deterministic.
Assembly: mscorlib (in mscorlib.dll)
| Name | Description | |
|---|---|---|
![]() | OnDeserializedAttribute() | Initializes a new instance of the OnDeserializedAttribute class. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object) | This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.) |
![]() | GetHashCode() | Returns the hash code for this instance.(Inherited from Attribute.) |
![]() | GetType() | |
![]() | 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(Object) | When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.) |
![]() | ToString() | Returns a string that represents the current object.(Inherited from Object.) |
| Name | Description | |
|---|---|---|
![]() ![]() | _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) | Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.) |
![]() ![]() | _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) | 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) | 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) | Provides access to properties and methods exposed by an object.(Inherited from Attribute.) |
Use the OnDeserializedAttribute when you need to fix values on a deserialized object after it has been deserialized and before the graph is returned. This attribute can be used instead of the IDeserializationCallback interface.
To use the OnDeserializedAttribute, the method must contain a StreamingContext parameter. The attribute marks the method to be called by the serialization infrastructure and the StreamingContext provides additional data about the type of serialization taking place. The usage is shown in the following code:
<OnDeserialized()> _ Private Sub SetValuesOnDeserialized(ByVal context As StreamingContext) ' Code not shown. End Sub
Note |
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In your code, you can use the word OnDeserialized instead of the longer OnDeserializedAttribute. |
The following example applies the OnDeserializedAttribute, OnSerializingAttribute, OnSerializedAttribute, and OnDeserializingAttribute attributes to methods in a class.
Imports System Imports System.IO Imports System.Runtime.Serialization Imports System.Runtime.Serialization.Formatters.Binary Public Class Test Public Shared Sub Main() ' Create a new TestSimpleObject object. Dim obj As New TestSimpleObject() Console.WriteLine(vbLf + " Before serialization the object contains: ") obj.Print() ' Open a file and serialize the object into binary format. Dim stream As Stream = File.Open("DataFile.dat", FileMode.Create) Dim formatter As New BinaryFormatter() Try formatter.Serialize(stream, obj) ' Print the object again to see the effect of the 'OnSerializedAttribute. Console.WriteLine(vbLf + " After serialization the object contains: ") obj.Print() ' Set the original variable to null. obj = Nothing stream.Close() ' Open the file "DataFile.dat" and deserialize the object from it. stream = File.Open("DataFile.dat", FileMode.Open) ' Deserialize the object from the data file. obj = CType(formatter.Deserialize(stream), TestSimpleObject) Console.WriteLine(vbLf + " After deserialization the object contains: ") obj.Print() Console.ReadLine() Catch se As SerializationException Console.WriteLine("Failed to serialize. Reason: " + se.Message) Throw Catch exc As Exception Console.WriteLine("An exception occurred. Reason: " + exc.Message) Throw Finally stream.Close() obj = Nothing formatter = Nothing End Try End Sub End Class ' This is the object that will be serialized and deserialized. <Serializable()> _ Public Class TestSimpleObject ' This member is serialized and deserialized with no change. Public member1 As Integer ' The value of this field is set and reset during and ' after serialization. Private member2 As String ' This field is not serialized. The OnDeserializedAttribute ' is used to set the member value after serialization. <NonSerialized()> _ Public member3 As String ' This field is set to null, but populated after deserialization. Private member4 As String ' Constructor for the class. Public Sub New() member1 = 11 member2 = "Hello World!" member3 = "This is a nonserialized value" member4 = Nothing End Sub Public Sub Print() Console.WriteLine("member1 = '{0}'", member1) Console.WriteLine("member2 = '{0}'", member2) Console.WriteLine("member3 = '{0}'", member3) Console.WriteLine("member4 = '{0}'", member4) End Sub <OnSerializing()> _ Friend Sub OnSerializingMethod(ByVal context As StreamingContext) member2 = "This value went into the data file during serialization." End Sub <OnSerialized()> _ Friend Sub OnSerializedMethod(ByVal context As StreamingContext) member2 = "This value was reset after serialization." End Sub <OnDeserializing()> _ Friend Sub OnDeserializingMethod(ByVal context As StreamingContext) member3 = "This value was set during deserialization" End Sub <OnDeserialized()> _ Friend Sub OnDeserializedMethod(ByVal context As StreamingContext) member4 = "This value was set after deserialization." End Sub End Class ' Output: ' Before serialization the object contains: ' member1 = '11' ' member2 = 'Hello World!' ' member3 = 'This is a nonserialized value' ' member4 = '' ' ' After serialization the object contains: ' member1 = '11' ' member2 = 'This value was reset after serialization.' ' member3 = 'This is a nonserialized value' ' member4 = '' ' ' After deserialization the object contains: ' member1 = '11' ' member2 = 'This value went into the data file during serialization.' ' member3 = 'This value was set during deserialization' ' member4 = 'This value was set after deserialization.'
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 3.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.




