Artigo
11/18/2011

DataContractJsonSerializer Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Serializes objects to the JavaScript Object Notation (JSON) and deserializes JSON data to objects. This class cannot be inherited.

Inheritance Hierarchy

System.Object
System.Runtime.Serialization.Json.DataContractJsonSerializer

Namespace: System.Runtime.Serialization.Json
Assembly: System.ServiceModel.Web (in System.ServiceModel.Web.dll)

Syntax

'Declaration
Public NotInheritable Class DataContractJsonSerializer

public sealed class DataContractJsonSerializer

The DataContractJsonSerializer type exposes the following members.

Constructors

	Name	Description
	DataContractJsonSerializer(Type)	Initializes a new instance of the DataContractJsonSerializer class to serialize or deserialize an object of the specified type.
	DataContractJsonSerializer(Type, IEnumerable<Type>)	Initializes a new instance of the DataContractJsonSerializer class to serialize or deserialize an object of a specified type with a collection of known types that may be present in the object graph.

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Properties

	Name	Description
	KnownTypes	Gets a collection of types that may be present in the object graph serialized using this instance of the DataContractJsonSerializer.

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Methods

	Name	Description
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ReadObject	Reads a document stream in the JSON (JavaScript Object Notation) format and returns the deserialized object.
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	WriteObject	Serializes a specified object to JavaScript Object Notation (JSON) data and writes the resulting JSON to a stream.

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Remarks

Use the DataContractJsonSerializer class to serialize instances of a type into a JSON document and to deserialize a JSON document into an instance of a type. For example, you can create a type named Person with properties that contain essential data, such as a name and address. You can then create and manipulate an instance of the Person class and write all of its property values in a JSON document for later retrieval. This JSON document can later be deserialized into the Person class or another class with an equivalent data contract.

Examples

Namespace SL_DataContractJsonSerializer
    Partial Public Class Page
        Inherits UserControl
        Public Sub New()
            InitializeComponent()
        End Sub

        'This uses an event handler, not SL data binding
        Private Sub OnClick(ByVal sender As Object, ByVal args As EventArgs)
            txtOutput1.Text = "Create a User object and serialize it."
            Dim json As String = WriteFromObject()
            txtOutput2.Text = json.ToString() ' Displays: {"Age":42,"Name":"Bob"}

            txtOutput3.Text = "Deserialize the data to a User object."
            Dim jsonString As String = "{'Name':'Bill', 'Age':53}"
            Dim deserializedUser As User = ReadToObject(jsonString)
            txtOutput4.Text = deserializedUser.Name ' Displays: Bill
            txtOutput5.Text = deserializedUser.Age.ToString() ' Displays: 53
        End Sub
        ' Create a User object and serialize it to a JSON stream.
        Public Shared Function WriteFromObject() As String
            'Create User object.
            Dim user As New User("Bob", 42)

            'Create a stream to serialize the object to.
            Dim ms As New MemoryStream()

            ' Serializer the User object to the stream.
            Dim ser As New DataContractJsonSerializer(GetType(User))
            ser.WriteObject(ms, user)
            Dim json() As Byte = ms.ToArray()
            ms.Close()
            Return Encoding.UTF8.GetString(json, 0, json.Length)

        End Function

        ' Deserialize a JSON stream to a User object.
        Public Shared Function ReadToObject(ByVal json As String) As User
            Dim deserializedUser As New User()
            Dim ms As New MemoryStream(Encoding.UTF8.GetBytes(json))
            Dim ser As New DataContractJsonSerializer(deserializedUser.GetType())
            deserializedUser = TryCast(ser.ReadObject(ms), User)
            ms.Close()
            Return deserializedUser
        End Function

    End Class

    <DataContract> _
    Public Class User
        Private privateName As String
        <DataMember> _
        Public Property Name() As String
            Get
                Return privateName
            End Get
            Set(ByVal value As String)
                privateName = value
            End Set
        End Property

        Private privateAge As Integer
        <DataMember> _
        Public Property Age() As Integer
            Get
                Return privateAge
            End Get
            Set(ByVal value As Integer)
                privateAge = value
            End Set
        End Property

        Public Sub New()
        End Sub

        Public Sub New(ByVal newName As String, ByVal newAge As Integer)
            Name = newName
            Age = newAge
        End Sub

    End Class

End Namespace

namespace SL_DataContractJsonSerializer
{
    public partial class Page : UserControl
    {
        public Page()
        {
            InitializeComponent();
        }

        //This uses an event handler, not SL data binding
        void OnClick(object sender, EventArgs args)
        {
            txtOutput1.Text = "Create a User object and serialize it.";
            string json = WriteFromObject();
            txtOutput2.Text = json.ToString(); // Displays: {"Age":42,"Name":"Bob"}

            txtOutput3.Text = "Deserialize the data to a User object.";
            string jsonString = "{'Name':'Bill', 'Age':53}";
            User deserializedUser = ReadToObject(jsonString);
            txtOutput4.Text = deserializedUser.Name; // Displays: Bill
            txtOutput5.Text = deserializedUser.Age.ToString(); // Displays: 53
        }
        // Create a User object and serialize it to a JSON stream.
        public static string WriteFromObject()
        {
            //Create User object.
            User user = new User("Bob", 42);

            //Create a stream to serialize the object to.
            MemoryStream ms = new MemoryStream();

            // Serializer the User object to the stream.
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(User));
            ser.WriteObject(ms, user);
            byte[] json = ms.ToArray();
            ms.Close();
            return Encoding.UTF8.GetString(json, 0, json.Length);

        }

        // Deserialize a JSON stream to a User object.
        public static User ReadToObject(string json)
        {
            User deserializedUser = new User();
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(json));
            DataContractJsonSerializer ser = new DataContractJsonSerializer(deserializedUser.GetType());
            deserializedUser = ser.ReadObject(ms) as User;
            ms.Close();
            return deserializedUser;
        }

    }

    [DataContract]
    public class User
    {
        [DataMember]
        public string Name { get; set; }

        [DataMember]
        public int Age { get; set; }

        public User() { }

        public User(string newName, int newAge)
        {
            Name = newName;
            Age = newAge;
        }

    }

}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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