Upgrade your Internet Experience
Microsoft.com
Welcome Sign in
.NET Framework Developer Center
Click to Rate and Give Feedback

  Switch on low bandwidth view
This page is specific to
Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:
.NET Framework Class Library
JavaScriptSerializer Class

Provides serialization and deserialization functionality for AJAX-enabled applications.

Namespace:  System.Web.Script.Serialization
Assembly:  System.Web.Extensions (in System.Web.Extensions.dll)
Visual Basic (Declaration)
<AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
<AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
Public Class JavaScriptSerializer
Visual Basic (Usage)
Dim instance As JavaScriptSerializer
C#
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class JavaScriptSerializer
Visual C++
[AspNetHostingPermissionAttribute(SecurityAction::InheritanceDemand, Level = AspNetHostingPermissionLevel::Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction::LinkDemand, Level = AspNetHostingPermissionLevel::Minimal)]
public ref class JavaScriptSerializer
JScript
public class JavaScriptSerializer

The JavaScriptSerializer class is used internally by the asynchronous communication layer to serialize and deserialize the data that is passed between the browser and the Web server. You cannot access that instance of the serializer. However, this class exposes a public API. Therefore, you can use the class when you want to work with JavaScript Object Notation (JSON) in managed code.

To serialize an object, use the Serialize method. To deserialize a JSON string, use the Deserialize<(Of <(T>)>) or DeserializeObject methods. To serialize and deserialize types that are not natively supported by JavaScriptSerializer, implement custom converters by using the JavaScriptConverter class. Then register the converters by using the RegisterConverters method.

Mapping Between Managed Types and JSON

The following table shows the mapping between managed types and JSON for the serialization process. These managed types are natively supported by JavaScriptSerializer. When you are deserializing from a JSON string to a managed type, the same mapping applies. However, deserialization can be asymmetric; not all serializable managed types can be deserialized from JSON.

NoteNote:

A multidimensional array is serialized as a one-dimensional array, and you should use it as a flat array.

Managed type

JSON equivalent

String (UTF-8 encoding only).

String

Char

String

Single null char (such as, \0 )

Null

Boolean

Boolean. Represented in JSON as true or false

nullNothingnullptra null reference (Nothing in Visual Basic) (nullNothingnullptra null reference (Nothing in Visual Basic) object references and Nullable value types).

A string value of null

DBNull

A string value of null

Primitive numeric (or numeric-compatible) types: Byte, SByte, Int16, Int32, Int64, UInt16, UInt32, UInt64, Double, and Single. The culture-invariant string representation is used.

Number

DateTime

Date object, represented in JSON as "\/Date(number of ticks)\/". The number of ticks is a positive or negative long value that indicates the number of ticks (milliseconds) that have elapsed since midnight 01 January, 1970 UTC.

The maximum supported date value is MaxValue (12/31/9999 11:59:59 PM) and the minimum supported date value is MinValue (1/1/0001 12:00:00 AM).

Enumerations of integer type

Integer equivalent of the enumeration value

Types that implement IEnumerable or System.Collections.Generic..::.IEnumerable<(Of <(T>)>) that are not also implementations of IDictionary or System.Collections.Generic..::.IDictionary<(Of <(TKey, TValue>)>). This includes types such as Array, ArrayList, and List<(Of <(T>)>).

Array that uses JSON array syntax

Types that implement IDictionary or System.Collections.Generic..::.IDictionary<(Of <(TKey, TValue>)>). This includes types such as Dictionary<(Of <(TKey, TValue>)>) and Hashtable.

JavaScript object that uses JSON dictionary syntax

Custom concrete (non-abstract) types that have public instance properties that have get accessors or public instance fields.

Note that public write-only properties, public property or public field attributes marked with ScriptIgnoreAttribute, and public indexed properties in these types are ignored.

JavaScript object that uses JSON dictionary syntax. A special metadata property named "__type" is included to ensure correct deserialization. Make sure that public instance properties have get and set accessors to ensure correct deserialization.

Guid

String representation of a GUID

Uri

String representation of the return value of GetComponents

The following example shows how to use the JavaScriptSerializer class to save and restore the state of an object by using JSON serialization. This code uses a custom converter that is provided for the JavaScriptConverter class.

Visual Basic
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Web.Script.Serialization" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    Dim serializer As JavaScriptSerializer

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        serializer = New JavaScriptSerializer()

        ' Register the custom converter.
        serializer.RegisterConverters(New JavaScriptConverter() _
            {New System.Web.Script.Serialization.VB.ListItemCollectionConverter()})
    End Sub

    Protected Sub saveButton_Click(ByVal sender As Object, ByVal e As EventArgs)
        ' Save the current state of the ListBox control.
        SavedState.Text = serializer.Serialize(ListBox1.Items)
        recoverButton.Enabled = True
        Message.Text = "State saved"
    End Sub

    Protected Sub recoverButton_Click(ByVal sender As Object, ByVal e As EventArgs)
        ' Recover the saved items of the ListBox control.        
        Dim recoveredList As ListItemCollection = _
            serializer.Deserialize(Of ListItemCollection)(SavedState.Text)
        Dim newListItemArray(recoveredList.Count - 1) As ListItem
        recoveredList.CopyTo(newListItemArray, 0)
        ListBox1.Items.Clear()
        ListBox1.Items.AddRange(newListItemArray)
        Message.Text = "Last saved state recovered."
    End Sub

    Protected Sub clearButton_Click(ByVal sender As Object, ByVal e As EventArgs)
        ' Remove all items from the ListBox control.
        ListBox1.Items.Clear()
        Message.Text = "All items removed"
    End Sub

    Protected Sub ContactsGrid_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
        ' Get the currently selected row using the SelectedRow property.
        Dim row As GridViewRow = ContactsGrid.SelectedRow

        ' Get the ID of the item selected.
        Dim itemId As String = ContactsGrid.DataKeys(row.RowIndex).Value.ToString()
        Dim newItem As ListItem = New ListItem(row.Cells(4).Text, itemId)

        ' Check if the item already exists in the ListBox control.
        If Not ListBox1.Items.Contains(newItem) Then
            ' Add the item to the ListBox control.
            ListBox1.Items.Add(newItem)
            Message.Text = "Item added"
        Else
            Message.Text = "Item already exists"
        End If

    End Sub

    Private Function SearchItem(ByVal itemId As String) As Boolean
        Dim i As Integer
        For i = 0 To ListBox1.Items.Count - 1
            If ListBox1.Items(i).Value = itemId Then
                Return True
            End If
        Next i
        Return False

    End Function

    Protected Sub ContactsGrid_PageIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
        ContactsGrid.SelectedIndex = -1
    End Sub

    Protected Sub searchButton_Click(ByVal sender As Object, ByVal e As EventArgs)
        ContactsGrid.SelectedIndex = -1
        ContactsGrid.PageIndex = 0
        ScriptManager1.SetFocus(TextBox1)
    End Sub

    Protected Sub CheckBox1_CheckedChanged(ByVal sender As Object, ByVal e As EventArgs)
        SavedState.Visible = CheckBox1.Checked
        StateLabel.Visible = CheckBox1.Checked
    End Sub
</script>

<html  >
<head runat="server">
    <title>Save/Recover state</title>
    <style type="text/css">
        body {  font: 11pt Trebuchet MS;
                font-color: #000000;
                padding-top: 72px;
                text-align: center }

        .text { font: 8pt Trebuchet MS }
    </style>
</head>
<body>    
    <form id="form1" runat="server" defaultbutton="searchButton" defaultfocus="TextBox1">
        <h3>
            <span style="text-decoration: underline">
                                    Contacts Selection</span><br />
        </h3>
        <asp:ScriptManager runat="server" ID="ScriptManager1" />
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                Type contact's first name:
                <asp:TextBox ID="TextBox1" runat="server" />
                <asp:Button ID="searchButton" runat="server" Text="Search" OnClick="searchButton_Click" />&nbsp;
                <br />
                <br />
                <table border="0" width="100%">
                    <tr>
                        <td style="width:50%" valign="top" align="center">
                            <b>Search results:</b><br />
                            <asp:GridView ID="ContactsGrid" runat="server" AutoGenerateColumns="False"
                                CellPadding="4" DataKeyNames="ContactID" DataSourceID="SqlDataSource1"
                                OnSelectedIndexChanged="ContactsGrid_SelectedIndexChanged" ForeColor="#333333" GridLines="None" AllowPaging="True" PageSize="7" OnPageIndexChanged="ContactsGrid_PageIndexChanged">
                                <Columns>
                                    <asp:CommandField ShowSelectButton="True" ButtonType="Button" />
                                    <asp:BoundField DataField="ContactID" HeaderText="ContactID" SortExpression="ContactID" Visible="False" />
                                    <asp:BoundField DataField="FirstName" HeaderText="FirstName" SortExpression="FirstName" />
                                    <asp:BoundField DataField="LastName" HeaderText="LastName" SortExpression="LastName" />
                                    <asp:BoundField DataField="EmailAddress" HeaderText="EmailAddress" SortExpression="EmailAddress" />
                                </Columns>
                                <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
                                <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                                <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                <EditRowStyle BackColor="#999999" />
                                <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                                <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                                <EmptyDataTemplate>No data found.</EmptyDataTemplate>
                            </asp:GridView>
                            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
                                SelectCommand="SELECT ContactID, FirstName, LastName, EmailAddress FROM Person.Contact WHERE (UPPER(FirstName) = UPPER(@FIRSTNAME))" >
                                <SelectParameters>
                                    <asp:ControlParameter Name="FIRSTNAME" ControlId="TextBox1" Type="String" />
                                </SelectParameters>
                            </asp:SqlDataSource>
                        </td>
                        <td valign="top">
                            <b>Contacts list:</b><br />
                        <asp:ListBox ID="ListBox1" runat="server" Height="200px" Width="214px" /><br />
                        <asp:Button ID="saveButton" runat="server" Text="Save state" OnClick="saveButton_Click" ToolTip="Save the current state of the list" />
                        <asp:Button ID="recoverButton" runat="server" Text="Recover saved state" OnClick="recoverButton_Click" Enabled="false" ToolTip="Recover the last saved state" />
                        <asp:Button ID="clearButton" runat="server" Text="Clear" OnClick="clearButton_Click" ToolTip="Remove all items from the list" /><br />
                            <br />
                            <asp:CheckBox ID="CheckBox1" runat="server" Checked="True" OnCheckedChanged="CheckBox1_CheckedChanged"
                                Text="Show saved state" AutoPostBack="True" /></td>
                    </tr>
                    <tr>
                        <td colspan="2">
                            <br />
                            <br />
                            &nbsp;&nbsp;
                            <hr />
                            Message: <asp:Label ID="Message" runat="server" ForeColor="SteelBlue" />&nbsp;&nbsp;<br />
                            <asp:Label ID="StateLabel" runat="server" Text="State:"></asp:Label>
                            <asp:Label ID="SavedState" runat="server"/><br />                        
                        </td>
                    </tr>
                </table>
            </ContentTemplate>
        </asp:UpdatePanel>
        <asp:UpdateProgress ID="UpdateProgress1" runat="server">
            <ProgressTemplate>
                <asp:Image ID="Image1" runat="server" ImageUrl="..\images\spinner.gif" />&nbsp;Processing...
            </ProgressTemplate>
        </asp:UpdateProgress>
    </form>
</body>
</html>
C#
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Script.Serialization" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

    JavaScriptSerializer serializer;
    protected void Page_Load(object sender, EventArgs e)
    {
        serializer = new JavaScriptSerializer();

        // Register the custom converter.
        serializer.RegisterConverters(new JavaScriptConverter[] { 
            new System.Web.Script.Serialization.CS.ListItemCollectionConverter() });
        this.SetFocus(TextBox1);
    }

    protected void saveButton_Click(object sender, EventArgs e)
    {
        // Save the current state of the ListBox control.
        SavedState.Text = serializer.Serialize(ListBox1.Items);
        recoverButton.Enabled = true;
        Message.Text = "State saved";
    }

    protected void recoverButton_Click(object sender, EventArgs e)
    {        
        //Recover the saved items of the ListBox control.
        ListItemCollection recoveredList = serializer.Deserialize<ListItemCollection>(SavedState.Text);
        ListItem[] newListItemArray = new ListItem[recoveredList.Count];
        recoveredList.CopyTo(newListItemArray, 0);
        ListBox1.Items.Clear();
        ListBox1.Items.AddRange(newListItemArray);
        Message.Text = "Last saved state recovered.";
    }

    protected void clearButton_Click(object sender, EventArgs e)
    {
        // Remove all items from the ListBox control.
        ListBox1.Items.Clear();
        Message.Text = "All items removed";
    }

    protected void ContactsGrid_SelectedIndexChanged(object sender, EventArgs e)
    {
        // Get the currently selected row using the SelectedRow property.
        GridViewRow row = ContactsGrid.SelectedRow;

        // Get the ID of item selected.
        string itemId = ContactsGrid.DataKeys[row.RowIndex].Value.ToString();                
        ListItem newItem = new ListItem(row.Cells[4].Text, itemId);

        // Check if the item already exists in the ListBox control.
        if (!ListBox1.Items.Contains(newItem))
        {
            // Add the item to the ListBox control.
            ListBox1.Items.Add(newItem);
            Message.Text = "Item added";
        }
        else
            Message.Text = "Item already exists";
    }

    protected void ContactsGrid_PageIndexChanged(object sender, EventArgs e)
    {
        //Reset the selected index.
        ContactsGrid.SelectedIndex = -1;
    }

    protected void searchButton_Click(object sender, EventArgs e)
    {
        //Reset indexes.
        ContactsGrid.SelectedIndex = -1;
        ContactsGrid.PageIndex = 0;

        //Set focus on the TextBox control.
        ScriptManager1.SetFocus(TextBox1);
    }

    protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
    {
        // Show/hide the saved state string.        
        SavedState.Visible = CheckBox1.Checked;
        StateLabel.Visible = CheckBox1.Checked;
    }
</script>

<html  >
<head runat="server">
    <title>Save/Recover state</title>
    <style type="text/css">
        body {  font: 11pt Trebuchet MS;
                font-color: #000000;
                padding-top: 72px;
                text-align: center }

        .text { font: 8pt Trebuchet MS }
    </style>
</head>
<body>    
    <form id="form1" runat="server" defaultbutton="searchButton" defaultfocus="TextBox1">
        <h3>
            <span style="text-decoration: underline">
                                    Contacts Selection</span><br />
        </h3>
        <asp:ScriptManager runat="server" ID="ScriptManager1" />
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                Type contact's first name:
                <asp:TextBox ID="TextBox1" runat="server" />
                <asp:Button ID="searchButton" runat="server" Text="Search" OnClick="searchButton_Click" />&nbsp;
                <br />
                <br />
                <table border="0" width="100%">
                    <tr>
                        <td style="width:50%" valign="top" align="center">
                            <b>Search results:</b><br />
                            <asp:GridView ID="ContactsGrid" runat="server" AutoGenerateColumns="False"
                                CellPadding="4" DataKeyNames="ContactID" DataSourceID="SqlDataSource1"
                                OnSelectedIndexChanged="ContactsGrid_SelectedIndexChanged" ForeColor="#333333" GridLines="None" AllowPaging="True" PageSize="7" OnPageIndexChanged="ContactsGrid_PageIndexChanged">
                                <Columns>
                                    <asp:CommandField ShowSelectButton="True" ButtonType="Button" />
                                    <asp:BoundField DataField="ContactID" HeaderText="ContactID" SortExpression="ContactID" Visible="False" />
                                    <asp:BoundField DataField="FirstName" HeaderText="FirstName" SortExpression="FirstName" />
                                    <asp:BoundField DataField="LastName" HeaderText="LastName" SortExpression="LastName" />
                                    <asp:BoundField DataField="EmailAddress" HeaderText="EmailAddress" SortExpression="EmailAddress" />
                                </Columns>
                                <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
                                <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
                                <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
                                <EditRowStyle BackColor="#999999" />
                                <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
                                <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
                                <EmptyDataTemplate>No data found.</EmptyDataTemplate>
                            </asp:GridView>
                            <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:AdventureWorksConnectionString %>"
                                SelectCommand="SELECT ContactID, FirstName, LastName, EmailAddress FROM Person.Contact WHERE (UPPER(FirstName) = UPPER(@FIRSTNAME))" >
                                <SelectParameters>
                                    <asp:ControlParameter Name="FIRSTNAME" ControlId="TextBox1" Type="String" />
                                </SelectParameters>
                            </asp:SqlDataSource>
                        </td>
                        <td valign="top">
                            <b>Contacts list:</b><br />
                        <asp:ListBox ID="ListBox1" runat="server" Height="200px" Width="214px" /><br />
                        <asp:Button ID="saveButton" runat="server" Text="Save state" OnClick="saveButton_Click" ToolTip="Save the current state of the list" />
                        <asp:Button ID="recoverButton" runat="server" Text="Recover saved state" OnClick="recoverButton_Click" Enabled="false" ToolTip="Recover the last saved state" />
                        <asp:Button ID="clearButton" runat="server" Text="Clear" OnClick="clearButton_Click" ToolTip="Remove all items from the list" /><br />
                            <br />
                            <asp:CheckBox ID="CheckBox1" runat="server" Checked="True" OnCheckedChanged="CheckBox1_CheckedChanged"
                                Text="Show saved state" AutoPostBack="True" /></td>
                    </tr>
                    <tr>
                        <td colspan="2">
                            <br />
                            <br />
                            &nbsp;&nbsp;
                            <hr />
                            Message: <asp:Label ID="Message" runat="server" ForeColor="SteelBlue" />&nbsp;&nbsp;<br />
                            <asp:Label ID="StateLabel" runat="server" Text="State:"></asp:Label>
                            <asp:Label ID="SavedState" runat="server"/><br />                        
                        </td>
                    </tr>
                </table>
            </ContentTemplate>
        </asp:UpdatePanel>
        <asp:UpdateProgress ID="UpdateProgress1" runat="server">
            <ProgressTemplate>
                <asp:Image ID="Image1" runat="server" ImageUrl="..\images\spinner.gif" />&nbsp;Processing...
            </ProgressTemplate>
        </asp:UpdateProgress>
    </form>
</body>
</html>
System..::.Object
  System.Web.Script.Serialization..::.JavaScriptSerializer
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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.

.NET Framework

Supported in: 3.5
Tags What's this?: Add a tag
Community Content   What is Community Content?
Add new content RSS  Annotations
© 2009 Microsoft Corporation. All rights reserved. Terms of Use  |  Trademarks  |  Privacy Statement
Page view tracker