JavaScriptSerializer 类
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
对于 .NET Framework 4.7.2 及更高版本,请使用命名空间中的 System.Text.Json API 进行序列化和反序列化。 对于早期版本的 .NET Framework,请使用 Newtonsoft.Json。 此类型旨在为已启用 AJAX 的应用程序提供序列化和反序列化功能。
public ref class JavaScriptSerializer
public class JavaScriptSerializer
type JavaScriptSerializer = class
Public Class JavaScriptSerializer
- 继承
-
JavaScriptSerializer
示例
第一个示例提供了有关如何序列化和反序列化数据对象的简单说明。 它需要名为 Person 的类,如下所示。
using System;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.Script.Serialization;
namespace ExampleApplication
{
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{
var RegisteredUsers = new List<Person>();
RegisteredUsers.Add(new Person() { PersonID = 1, Name = "Bryon Hetrick", Registered = true });
RegisteredUsers.Add(new Person() { PersonID = 2, Name = "Nicole Wilcox", Registered = true });
RegisteredUsers.Add(new Person() { PersonID = 3, Name = "Adrian Martinson", Registered = false });
RegisteredUsers.Add(new Person() { PersonID = 4, Name = "Nora Osborn", Registered = false });
var serializer = new JavaScriptSerializer();
var serializedResult = serializer.Serialize(RegisteredUsers);
// Produces string value of:
// [
// {"PersonID":1,"Name":"Bryon Hetrick","Registered":true},
// {"PersonID":2,"Name":"Nicole Wilcox","Registered":true},
// {"PersonID":3,"Name":"Adrian Martinson","Registered":false},
// {"PersonID":4,"Name":"Nora Osborn","Registered":false}
// ]
var deserializedResult = serializer.Deserialize<List<Person>>(serializedResult);
// Produces List with 4 Person objects
}
}
}
Imports System.Web.Script.Serialization
Public Class _Default
Inherits Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim RegisteredUsers As New List(Of Person)()
RegisteredUsers.Add(New Person With {.PersonID = 1, .Name = "Bryon Hetrick", .Registered = True})
RegisteredUsers.Add(New Person With {.PersonID = 2, .Name = "Nicole Wilcox", .Registered = True})
RegisteredUsers.Add(New Person With {.PersonID = 3, .Name = "Adrian Martinson", .Registered = False})
RegisteredUsers.Add(New Person With {.PersonID = 4, .Name = "Nora Osborn", .Registered = False})
Dim serializer As New JavaScriptSerializer()
Dim serializedResult = serializer.Serialize(RegisteredUsers)
' Produces string value of:
' [
' {"PersonID":1,"Name":"Bryon Hetrick","Registered":true},
' {"PersonID":2,"Name":"Nicole Wilcox","Registered":true},
' {"PersonID":3,"Name":"Adrian Martinson","Registered":false},
' {"PersonID":4,"Name":"Nora Osborn","Registered":false}
' ]
Dim deserializedResult = serializer.Deserialize(Of List(Of Person))(serializedResult)
' Produces List with 4 Person objects
End Sub
End Class
namespace ExampleApplication
{
public class Person
{
public int PersonID { get; set; }
public string Name { get; set; }
public bool Registered { get; set; }
}
}
Public Class Person
Public Property PersonID As Integer
Public Property Name As String
Public Property Registered As Boolean
End Class
下一个示例演示了一个更复杂的完整项目,该项目使用 JavaScriptSerializer 类通过 JSON 序列化保存和还原对象的状态。 此代码使用为 JavaScriptConverter 类提供的自定义转换器。
<%@ 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)
{
//<Snippet1>
serializer = new JavaScriptSerializer();
// Register the custom converter.
serializer.RegisterConverters(new JavaScriptConverter[] {
new System.Web.Script.Serialization.CS.ListItemCollectionConverter() });
//</Snippet1>
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 xmlns="http://www.w3.org/1999/xhtml" >
<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" />
<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 />
<hr />
Message: <asp:Label ID="Message" runat="server" ForeColor="SteelBlue" /> <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" /> Processing...
</ProgressTemplate>
</asp:UpdateProgress>
</form>
</body>
</html>
<%@ 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)
'<Snippet1>
serializer = New JavaScriptSerializer()
' Register the custom converter.
serializer.RegisterConverters(New JavaScriptConverter() _
{New System.Web.Script.Serialization.VB.ListItemCollectionConverter()})
'</Snippet1>
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 xmlns="http://www.w3.org/1999/xhtml" >
<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" />
<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 />
<hr />
Message: <asp:Label ID="Message" runat="server" ForeColor="SteelBlue" /> <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" /> Processing...
</ProgressTemplate>
</asp:UpdateProgress>
</form>
</body>
</html>
注解
重要
对于 .NET Framework 4.7.2 及更高版本,命名空间中的 System.Text.Json API 应用于序列化和反序列化。 对于早期版本的 .NET Framework,请使用 Newtonsoft.Json。
该 JavaScriptSerializer 类由异步通信层在内部使用,用于序列化和反序列化浏览器与 Web 服务器之间传递的数据。 无法访问序列化程序的实例。 但是,此类公开公共 API。 因此,当想要在托管代码中使用 JavaScript 对象表示法 (JSON) 时,可以使用该类。
若要序列化对象,请使用 Serialize 该方法。 若要反序列化 JSON 字符串,请使用 Deserialize 或 DeserializeObject 方法。 若要序列化和反序列化不受本机支持 JavaScriptSerializer的类型,请使用 JavaScriptConverter 该类实现自定义转换器。 然后使用该方法注册转换器 RegisterConverters 。
托管类型和 JSON 之间的映射
下表显示了序列化过程的托管类型和 JSON 之间的映射。 这些托管类型本机受支持 JavaScriptSerializer。 将 JSON 字符串反序列化为托管类型时,将应用相同的映射。 但是,反序列化可以是非对称的;并非所有可序列化的托管类型都可以从 JSON 反序列化。
备注
多维数组序列化为一维数组,应将其用作平面数组。
托管类型 | JSON 等效项 |
---|---|
String 仅) (UTF-8 编码。 | 字符串 |
Char | 字符串 |
单个 null 字符 (,例如 \0 ) | Null |
Boolean | 布尔值。 以 JSON 表示为 true 或 false |
null``null (对象引用和Nullable值类型) 。 |
null 的字符串值 |
DBNull | null 的字符串值 |
基元数值 (或与数值兼容的) 类型:Byte、、Int64Int32Int16UInt32SByteUInt16、UInt64、、 Double和。Single 使用区域性固定字符串表示形式。 | Number |
DateTime | 日期对象,以 JSON 表示为“\/Date (时钟周期数) \/”。 刻度线数是正值或负长值,指示自 1970 年 1 月 1 日午夜以来已过) 的刻度数 (毫秒。 支持的最大日期值 (MaxValue 12/31/9999 下午 11:59:59) ,支持的最小日期值 (MinValue 1/1/0001 12:00:00 AM) 。 |
整数类型的枚举 | 枚举值的整数等效项 |
实现IEnumerable或不是实现或System.Collections.Generic.IEnumerable<T>System.Collections.Generic.IDictionary<TKey,TValue>实现的类型IDictionary。 这包括类型,例如 Array, ArrayList和 List<T>。 | 使用 JSON 数组语法的数组 |
实现 IDictionary 或 System.Collections.Generic.IDictionary<TKey,TValue>. 这包括类型,例如 Dictionary<TKey,TValue> 和 Hashtable。 | 使用 JSON 字典语法的 JavaScript 对象 |
自定义具体 (具有获取访问器或公共实例字段的公共实例属性的非抽象) 类型。 请注意,这些类型中标有 ScriptIgnoreAttribute公共写入属性、公共属性或公共字段属性以及公共索引属性将被忽略。 |
使用 JSON 字典语法的 JavaScript 对象。 包含名为“__type”的特殊元数据属性,以确保正确的反序列化。 确保公共实例属性具有获取和设置访问器,以确保正确的反序列化。 |
Guid | GUID 的字符串表示形式 |
Uri | 返回值的字符串表示形式 GetComponents |
构造函数
JavaScriptSerializer() |
初始化不具有类型解析程序的 JavaScriptSerializer 类的新实例。 |
JavaScriptSerializer(JavaScriptTypeResolver) |
初始化具有自定义类型解析程序的 JavaScriptSerializer 类的新实例。 |
属性
MaxJsonLength |
获取或设置 JavaScriptSerializer 类接受的 JSON 字符串的最大长度。 |
RecursionLimit |
获取或设置用于约束要处理的对象级别的数量的限制。 |
方法
ConvertToType(Object, Type) |
将指定的对象转换成指定的类型。 |
ConvertToType<T>(Object) |
将给定对象转换为指定类型。 |
Deserialize(String, Type) |
将 JSON 格式字符串转换为指定类型的对象。 |
Deserialize<T>(String) |
将指定的 JSON 字符串转换为 |
DeserializeObject(String) |
将指定的 JSON 字符串转换为对象图。 |
Equals(Object) |
确定指定对象是否等于当前对象。 (继承自 Object) |
GetHashCode() |
作为默认哈希函数。 (继承自 Object) |
GetType() |
获取当前实例的 Type。 (继承自 Object) |
MemberwiseClone() |
创建当前 Object 的浅表副本。 (继承自 Object) |
RegisterConverters(IEnumerable<JavaScriptConverter>) |
使用 JavaScriptSerializer 实例注册自定义转换器。 |
Serialize(Object) |
将对象转换为 JSON 字符串。 |
Serialize(Object, StringBuilder) |
序列化对象并将生成的 JSON 字符串写入指定的 StringBuilder 对象。 |
ToString() |
返回表示当前对象的字符串。 (继承自 Object) |