ISerializable.GetObjectData(SerializationInfo, StreamingContext) Method

Definition

Namespace:

System.Runtime.Serialization

Assembly:

System.Runtime.dll

Populates a SerializationInfo with the data needed to serialize the target object.

public:
 void GetObjectData(System::Runtime::Serialization::SerializationInfo ^ info, System::Runtime::Serialization::StreamingContext context);

public void GetObjectData (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context);

abstract member GetObjectData : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> unit

Public Sub GetObjectData (info As SerializationInfo, context As StreamingContext)

Parameters

info

SerializationInfo

The SerializationInfo to populate with data.

context

StreamingContext

The destination (see StreamingContext) for this serialization.

Exceptions

SecurityException

The caller does not have the required permission.

Examples

The following example uses the GetObjectData method to set alternate values for a serialized object. The code uses the AddValue method of the SerializationInfo class to store the alternate values when the object is serialized. Conversely, when the constructor of the Person class is called during deserialization, the alternatve values are retrieved using the GetValue method and reassigned to the object's fields.

using System;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;
using System.IO;

namespace ISerializableExample
{
    class Program
    {
        public static void Main()
        {
            try
            {
                Run();
            }
            catch (Exception exc)
            {
                Console.WriteLine("{0}: {1}", exc.Message, exc.StackTrace);
            }
            finally
            {
                Console.WriteLine("Press Enter to exit....");
                Console.ReadLine();
            }
        }

        static void Run()
        {
            BinaryFormatter binaryFmt = new BinaryFormatter();
            Person p = new Person();
            p.IdNumber = 1010;
            p.Name = "AAAAA";
            FileStream fs = new FileStream
                ("Person.xml", FileMode.OpenOrCreate);
            binaryFmt.Serialize(fs, p);
            fs.Close();
            Console.WriteLine
                ("Original Name: {0}, Original ID: {1}", p.Name, p.IdNumber);

            // Deserialize.
            fs = new FileStream
                ("Person.xml", FileMode.OpenOrCreate);
            Person p2 = (Person)binaryFmt.Deserialize(fs);
                Console.WriteLine("New Name: {0}, New ID: {1}", p2.Name, p2.IdNumber);
            fs.Close();
            }
        }
    [Serializable]
    public class Person : ISerializable
    {
        private string name_value;
        private int ID_value;

        public Person() { }
        protected Person(SerializationInfo info, StreamingContext context)
        {
            if (info == null)
                throw new System.ArgumentNullException("info");
            name_value = (string)info.GetValue("AltName", typeof(string));
            ID_value = (int)info.GetValue("AltID", typeof(int));
        }

        public virtual void GetObjectData(
        SerializationInfo info, StreamingContext context)
        {
            if (info == null)
                throw new System.ArgumentNullException("info");
            info.AddValue("AltName", "XXX");
            info.AddValue("AltID", 9999);
        }

        public string Name
        {
            get { return name_value; }
            set { name_value = value; }
        }

        public int IdNumber
        {
            get { return ID_value; }
            set { ID_value = value; }
        }
    }
}

Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization
Imports System.Security.Permissions
Imports System.IO

<Assembly: SecurityPermission _
(SecurityAction.RequestMinimum, Execution:=True)> 

Class Program

    Public Shared Sub Main()
        Try
            Run()
        Catch exc As Exception
            Console.WriteLine("{0}: {1}", exc.Message, exc.StackTrace)
        Finally
            Console.WriteLine("Press Enter to exit....")
            Console.ReadLine()
        End Try

    End Sub

    Shared Sub Run()
        Dim binaryFmt As New BinaryFormatter()
        Dim p As New Person()
        p.IdNumber = 1010
        p.Name = "AAAAA"
        Dim fs As New FileStream("Person.xml", FileMode.OpenOrCreate)
        binaryFmt.Serialize(fs, p)
        fs.Close()
        Console.WriteLine _
        ("Original Name: {0}, Original ID: {1}", p.Name, p.IdNumber)

        ' Deserialize.
        fs = New FileStream("Person.xml", FileMode.OpenOrCreate)
        Dim p2 As Person = CType(binaryFmt.Deserialize(fs), Person)
        Console.WriteLine("New Name: {0}, New ID: {1}", _
        p2.Name, p2.IdNumber)
        fs.Close()
    End Sub
End Class

<Serializable()> _
Public Class Person
    Implements ISerializable
    Private name_value As String
    Private ID_value As Integer

    Public Sub New()

    End Sub

    Protected Sub New(ByVal info As SerializationInfo, _
    ByVal context As StreamingContext)
        If info Is Nothing Then
            Throw New System.ArgumentNullException("info")
        End If
        name_value = CStr(info.GetValue("AltName", GetType(String)))
        ID_value = Fix(info.GetValue("AltID", GetType(Integer)))

    End Sub

    <SecurityPermission(SecurityAction.LinkDemand, _
    Flags:=SecurityPermissionFlag.SerializationFormatter)> _
    Public Overridable Sub GetObjectData _
    (ByVal info As SerializationInfo, _
    ByVal context As StreamingContext) _
    Implements ISerializable.GetObjectData
        If info Is Nothing Then
            Throw New System.ArgumentNullException("info")
        End If
        info.AddValue("AltName", "XXX")
        info.AddValue("AltID", 9999)

    End Sub

    Public Property Name() As String
        Get
            Return name_value
        End Get
        Set(ByVal value As String)
            name_value = value
        End Set
    End Property

    Public Property IdNumber() As Integer
        Get
            Return ID_value
        End Get
        Set(ByVal value As Integer)
            ID_value = value
        End Set
    End Property
End Class

Remarks

Any objects that are included in the SerializationInfo are automatically tracked and serialized by the formatter.

Note

It is not guaranteed that this method will be called only once per object instance during serialization. Therefore, the method should be implemented in such a way that its behavior will be the same regardless of the number of times it is called.

See also

• StreamingContext
• SerializationInfo
• Custom serialization