SerializationInfoEnumerator Class

Definition

Fournit un mécanisme adapté au formateur pour l’analyse des données dans SerializationInfo.Provides a formatter-friendly mechanism for parsing the data in SerializationInfo. Cette classe ne peut pas être héritée.This class cannot be inherited.

public ref class SerializationInfoEnumerator sealed : System::Collections::IEnumerator
public sealed class SerializationInfoEnumerator : System.Collections.IEnumerator
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class SerializationInfoEnumerator : System.Collections.IEnumerator
type SerializationInfoEnumerator = class
    interface IEnumerator
Public NotInheritable Class SerializationInfoEnumerator
Implements IEnumerator
Inheritance
SerializationInfoEnumerator
Attributes
Implements

Examples

L’exemple de code suivant montre comment utiliser la classe FormatterServices pour sérialiser ou désérialiser correctement un objet dans lequel la classe de base n’implémente pas ISerializable mais la classe dérivée le fait.The following code example shows how to use the FormatterServices class in order to properly serialize or deserialize an object where the base class does not implement ISerializable but the derived class does.

using namespace System;
using namespace System::IO;
using namespace System::Runtime::Serialization;
using namespace System::Runtime::Serialization::Formatters;
using namespace System::Runtime::Serialization::Formatters::Binary;
using namespace System::Reflection;
using namespace System::Security::Permissions;

// Person is a serializable base class.
[Serializable]
public ref class Person
{
private:
    String^ title;

public:
    Person(String^ title)
    {
        this->title = title;
    }

public:
    virtual String^ ToString() override
    {
        return String::Format("{0}", title);
    }
};

// Employee is a serializable class derived from Person.
[Serializable]
public ref class Employee : public Person
{
private:
    String^ title;

public:
    Employee(String^ title) : Person("Person")
    {
        this->title = title;
    }

public:
    virtual String^ ToString() override
    {
        return String::Format("{0} -> {1}", title, Person::ToString());
    }
};

// Manager is a serializable and ISerializable class derived from Employee.
[Serializable]
ref class Manager : public Employee, public ISerializable
{
private:
    String^ title;

public:
    Manager() : Employee("Employee")
    {
        this->title = "Manager";
    }

public:
    [SecurityPermission(SecurityAction::Demand, SerializationFormatter = true)]
    virtual void GetObjectData(SerializationInfo^ info, StreamingContext context)
    {
        // Serialize the desired values for this class.
        info->AddValue("title", title);

        // Get the set of serializable members for the class and base classes.
        Type^ thisType = this->GetType();
        array<MemberInfo^>^ serializableMembers =
            FormatterServices::GetSerializableMembers(thisType, context);

        // Serialize the base class's fields to the info object.
        for each (MemberInfo^ serializableMember in serializableMembers)
        {
            // Do not serialize fields for this class.
            if (serializableMember->DeclaringType != thisType)
            {
                // Skip this field if it is marked NonSerialized.
                if (!(Attribute::IsDefined(serializableMember,
                    NonSerializedAttribute::typeid)))
                {
                    // Get the value of this field and add it to the
                    // SerializationInfo object.
                    info->AddValue(serializableMember->Name,
                        ((FieldInfo^)serializableMember)->GetValue(this));
                }
            }
        }

        // Call the method below to see the contents of the
        // SerializationInfo object.
        DisplaySerializationInfo(info);
    }

private:
    static void DisplaySerializationInfo(SerializationInfo^ info)
    {
        Console::WriteLine("Values in the SerializationInfo:");
        for each (SerializationEntry^ infoEntry in info)
        {
            Console::WriteLine("Name={0}, ObjectType={1}, Value={2}",
                infoEntry->Name, infoEntry->ObjectType, infoEntry->Value);
        }
    }

protected:
    Manager(SerializationInfo^ info,
        StreamingContext context) : Employee(nullptr)
    {
        // Get the set of serializable members for the class and base classes.
        Type^ thisType = this->GetType();
        array<MemberInfo^>^ serializableMembers =
            FormatterServices::GetSerializableMembers(thisType, context);

        // Deserialize the base class's fields from the info object.
        for each (MemberInfo^ serializableMember in serializableMembers)
        {
            // Do not deserialize fields for this class.
            if (serializableMember->DeclaringType != thisType)
            {
                // For easier coding, treat the member as a FieldInfo object
                FieldInfo^ fieldInformation = (FieldInfo^)serializableMember;

                // Skip this field if it is marked NonSerialized.
                if (!(Attribute::IsDefined(serializableMember,
                    NonSerializedAttribute::typeid)))
                {
                    // Get the value of this field from the
                    // SerializationInfo object.
                    fieldInformation->SetValue(this,
                        info->GetValue(fieldInformation->Name,
                        fieldInformation->FieldType));
                }
            }
        }

        // Deserialize the values that were serialized for this class.
        title = info->GetString("title");
    }

public:
    virtual String^ ToString() override
    {
        return String::Format("{0} -> {1}", title, Employee::ToString());
    }
};

int main()
{
    Stream^ stream = gcnew MemoryStream();
    IFormatter^ formatter = gcnew BinaryFormatter();
    Manager^ m = gcnew Manager();
    Console::WriteLine(m->ToString());
    formatter->Serialize(stream, m);

    stream->Position = 0;
    m = (Manager^) formatter->Deserialize(stream);
    Console::WriteLine(m->ToString());
}

// This code produces the following output.
//
//  Manager -> Employee -> Person
//  Values in the SerializaitonInfo:
//  Name=title, ObjectType=System.String, Value=Manager
//  Name=Employee+title, ObjectType=System.String, Value=Employee
//  Name=Person+title, ObjectType=System.String, Value=Person
//  Manager -> Employee -> Person
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters;
using System.Runtime.Serialization.Formatters.Binary;
using System.Reflection;
using System.Security.Permissions;

// Person is a serializable base class.
[Serializable]
public class Person
{
    private String title;

    public Person(String title)
    {
        this.title = title;
    }

    public override String ToString()
    {
        return String.Format("{0}", title);
    }
}

// Employee is a serializable class derived from Person.
[Serializable]
public class Employee : Person
{
    private String title;

    public Employee(String title) : base("Person")
    {
        this.title = title;
    }

    public override String ToString()
    {
        return String.Format("{0} -> {1}", title, base.ToString());
    }
}

// Manager is a serializable and ISerializable class derived from Employee.
[Serializable]
public class Manager : Employee, ISerializable
{
    private String title;

    public Manager() : base("Employee")
    {
        this.title = "Manager";
    }

    [SecurityPermission(SecurityAction.Demand, SerializationFormatter = true)]
    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {

        // Serialize the desired values for this class.
        info.AddValue("title", title);

        // Get the set of serializable members for the class and base classes.
        Type thisType = this.GetType();
        MemberInfo[] mi = FormatterServices.GetSerializableMembers(thisType, context);

        // Serialize the base class's fields to the info object.
        for (Int32 i = 0; i < mi.Length; i++)
        {
            // Do not serialize fields for this class.
            if (mi[i].DeclaringType == thisType) continue;

            // Skip this field if it is marked NonSerialized.
            if (Attribute.IsDefined(mi[i], typeof(NonSerializedAttribute))) continue;

            // Get the value of this field and add it to the SerializationInfo object.
            info.AddValue(mi[i].Name, ((FieldInfo) mi[i]).GetValue(this));
        }

        // Call the method below to see the contents of the SerializationInfo object.
        DisplaySerializationInfo(info);
    }

    private void DisplaySerializationInfo(SerializationInfo info)
    {
        SerializationInfoEnumerator e = info.GetEnumerator();
        Console.WriteLine("Values in the SerializationInfo:");
        while (e.MoveNext())
        {
            Console.WriteLine("Name={0}, ObjectType={1}, Value={2}", e.Name, e.ObjectType, e.Value);
        }
    }

    [SecurityPermissionAttribute(SecurityAction.Demand, Flags=SecurityPermissionFlag.SerializationFormatter)]
    protected Manager(SerializationInfo info, StreamingContext context) : base(null)
    {

        // Get the set of serializable members for the class and base classes.
        Type thisType = this.GetType();
        MemberInfo[] mi = FormatterServices.GetSerializableMembers(thisType, context);

        // Deserialize the base class's fields from the info object.
        for (Int32 i = 0; i < mi.Length; i++)
        {
            // Do not deserialize fields for this class.
            if (mi[i].DeclaringType == thisType) continue;

            // For easier coding, treat the member as a FieldInfo object
            FieldInfo fi = (FieldInfo) mi[i];

            // Skip this field if it is marked NonSerialized.
            if (Attribute.IsDefined(mi[i], typeof(NonSerializedAttribute))) continue;

            // Get the value of this field from the SerializationInfo object.
            fi.SetValue(this, info.GetValue(fi.Name, fi.FieldType));
        }

        // Deserialize the values that were serialized for this class.
        title = info.GetString("title");
    }

    public override String ToString()
    {
        return String.Format("{0} -> {1}", title, base.ToString());
    }
}

public sealed class App
{
    public static void Main()
    {
        Run();
    }

    public static void Run()
    {
        using (Stream stream = new MemoryStream())
    {
            IFormatter formatter = new BinaryFormatter();
            Manager m = new Manager();
            Console.WriteLine(m.ToString());
            formatter.Serialize(stream, m);

            stream.Position = 0;
            m = (Manager) formatter.Deserialize(stream);
            Console.WriteLine(m.ToString());
        }
    }
}
// This code produces the following output.
//
//  Manager -> Employee -> Person
//  Values in the SerializaitonInfo:
//  Name=title, ObjectType=System.String, Value=Manager
//  Name=Employee+title, ObjectType=System.String, Value=Employee
//  Name=Person+title, ObjectType=System.String, Value=Person
//  Manager -> Employee -> Person

Remarks

La classe actuelle est un énumérateur standard qui analyse les valeurs stockées dans SerializationInfo.The current class is a standard enumerator that parses over the values stored in SerializationInfo. Au lieu d’enregistrer les valeurs, le SerializationInfoEnumerator conserve les pointeurs vers les variables membres du SerializationInfo qui l’a créé.Instead of recording the values, the SerializationInfoEnumerator keeps pointers to the member variables of the SerializationInfo that created it.

Cette classe suit le mécanisme de IEnumerator.This class follows the IEnumerator mechanism.

Properties

Current

Obtient l'élément actuellement en cours d'examen.Gets the item currently being examined.

Name

Obtient le nom de l'élément qui est actuellement examiné.Gets the name for the item currently being examined.

ObjectType

Obtient le type d'élément en cours d'examen.Gets the type of the item currently being examined.

Value

Obtient la valeur de l'élément en cours d'examen.Gets the value of the item currently being examined.

Methods

Equals(Object)

Détermine si l'objet spécifié est identique à l'objet actuel.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Fait office de fonction de hachage par défaut.Serves as the default hash function.

(Inherited from Object)
GetType()

Obtient le Type de l'instance actuelle.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Crée une copie superficielle du Object actuel.Creates a shallow copy of the current Object.

(Inherited from Object)
MoveNext()

Met à jour l'énumérateur avec l'élément suivant.Updates the enumerator to the next item.

Reset()

Réaffecte à l'énumérateur la valeur du premier élément.Resets the enumerator to the first item.

ToString()

Retourne une chaîne qui représente l'objet actuel.Returns a string that represents the current object.

(Inherited from Object)

Explicit Interface Implementations

IEnumerator.Current

Obtient l'élément en cours dans la collection.Gets the current item in the collection.

Applies to

See also