XmlSerializer 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。
在对象和 XML 文档之间进行序列化和反序列化操作。 XmlSerializer 使您得以控制如何将对象编码到 XML 中。
public ref class XmlSerializer
public class XmlSerializer
type XmlSerializer = class
Public Class XmlSerializer
- 继承
-
XmlSerializer
示例
以下示例包含两个main类: PurchaseOrder
和 Test
。 类 PurchaseOrder
包含有关单个购买的信息。 类 Test
包含创建采购订单并读取所创建采购订单的方法。
#using <System.Xml.dll>
#using <System.dll>
using namespace System;
using namespace System::Xml;
using namespace System::Xml::Serialization;
using namespace System::IO;
ref class Address;
ref class OrderedItem;
/* The XmlRootAttribute allows you to set an alternate name
(PurchaseOrder) of the XML element, the element namespace; by
default, the XmlSerializer uses the class name. The attribute
also allows you to set the XML namespace for the element. Lastly,
the attribute sets the IsNullable property, which specifies whether
the xsi:null attribute appears if the class instance is set to
a null reference. */
[XmlRootAttribute("PurchaseOrder",Namespace="http://www.cpandl.com",
IsNullable=false)]
public ref class PurchaseOrder
{
public:
Address^ ShipTo;
String^ OrderDate;
/* The XmlArrayAttribute changes the XML element name
from the default of "OrderedItems" to "Items". */
[XmlArrayAttribute("Items")]
array<OrderedItem^>^OrderedItems;
Decimal SubTotal;
Decimal ShipCost;
Decimal TotalCost;
};
public ref class Address
{
public:
/* The XmlAttribute instructs the XmlSerializer to serialize the Name
field as an XML attribute instead of an XML element (the default
behavior). */
[XmlAttributeAttribute]
String^ Name;
String^ Line1;
/* Setting the IsNullable property to false instructs the
XmlSerializer that the XML attribute will not appear if
the City field is set to a null reference. */
[XmlElementAttribute(IsNullable=false)]
String^ City;
String^ State;
String^ Zip;
};
public ref class OrderedItem
{
public:
String^ ItemName;
String^ Description;
Decimal UnitPrice;
int Quantity;
Decimal LineTotal;
/* Calculate is a custom method that calculates the price per item,
and stores the value in a field. */
void Calculate()
{
LineTotal = UnitPrice * Quantity;
}
};
public ref class Test
{
public:
static void main()
{
// Read and write purchase orders.
Test^ t = gcnew Test;
t->CreatePO( "po.xml" );
t->ReadPO( "po.xml" );
}
private:
void CreatePO( String^ filename )
{
// Create an instance of the XmlSerializer class;
// specify the type of object to serialize.
XmlSerializer^ serializer = gcnew XmlSerializer( PurchaseOrder::typeid );
TextWriter^ writer = gcnew StreamWriter( filename );
PurchaseOrder^ po = gcnew PurchaseOrder;
// Create an address to ship and bill to.
Address^ billAddress = gcnew Address;
billAddress->Name = "Teresa Atkinson";
billAddress->Line1 = "1 Main St.";
billAddress->City = "AnyTown";
billAddress->State = "WA";
billAddress->Zip = "00000";
// Set ShipTo and BillTo to the same addressee.
po->ShipTo = billAddress;
po->OrderDate = System::DateTime::Now.ToLongDateString();
// Create an OrderedItem object.
OrderedItem^ i1 = gcnew OrderedItem;
i1->ItemName = "Widget S";
i1->Description = "Small widget";
i1->UnitPrice = (Decimal)5.23;
i1->Quantity = 3;
i1->Calculate();
// Insert the item into the array.
array<OrderedItem^>^items = {i1};
po->OrderedItems = items;
// Calculate the total cost.
Decimal subTotal = Decimal(0);
System::Collections::IEnumerator^ myEnum = items->GetEnumerator();
while ( myEnum->MoveNext() )
{
OrderedItem^ oi = safe_cast<OrderedItem^>(myEnum->Current);
subTotal = subTotal + oi->LineTotal;
}
po->SubTotal = subTotal;
po->ShipCost = (Decimal)12.51;
po->TotalCost = po->SubTotal + po->ShipCost;
// Serialize the purchase order, and close the TextWriter.
serializer->Serialize( writer, po );
writer->Close();
}
protected:
void ReadPO( String^ filename )
{
// Create an instance of the XmlSerializer class;
// specify the type of object to be deserialized.
XmlSerializer^ serializer = gcnew XmlSerializer( PurchaseOrder::typeid );
/* If the XML document has been altered with unknown
nodes or attributes, handle them with the
UnknownNode and UnknownAttribute events.*/
serializer->UnknownNode += gcnew XmlNodeEventHandler( this, &Test::serializer_UnknownNode );
serializer->UnknownAttribute += gcnew XmlAttributeEventHandler( this, &Test::serializer_UnknownAttribute );
// A FileStream is needed to read the XML document.
FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
// Declare an object variable of the type to be deserialized.
PurchaseOrder^ po;
/* Use the Deserialize method to restore the object's state with
data from the XML document. */
po = dynamic_cast<PurchaseOrder^>(serializer->Deserialize( fs ));
// Read the order date.
Console::WriteLine( "OrderDate: {0}", po->OrderDate );
// Read the shipping address.
Address^ shipTo = po->ShipTo;
ReadAddress( shipTo, "Ship To:" );
// Read the list of ordered items.
array<OrderedItem^>^items = po->OrderedItems;
Console::WriteLine( "Items to be shipped:" );
System::Collections::IEnumerator^ myEnum1 = items->GetEnumerator();
while ( myEnum1->MoveNext() )
{
OrderedItem^ oi = safe_cast<OrderedItem^>(myEnum1->Current);
Console::WriteLine( "\t{0}\t{1}\t{2}\t{3}\t{4}", oi->ItemName, oi->Description, oi->UnitPrice, oi->Quantity, oi->LineTotal );
}
Console::WriteLine( "\t\t\t\t\t Subtotal\t{0}", po->SubTotal );
Console::WriteLine( "\t\t\t\t\t Shipping\t{0}", po->ShipCost );
Console::WriteLine( "\t\t\t\t\t Total\t\t{0}", po->TotalCost );
}
void ReadAddress( Address^ a, String^ label )
{
// Read the fields of the Address object.
Console::WriteLine( label );
Console::WriteLine( "\t{0}", a->Name );
Console::WriteLine( "\t{0}", a->Line1 );
Console::WriteLine( "\t{0}", a->City );
Console::WriteLine( "\t{0}", a->State );
Console::WriteLine( "\t{0}", a->Zip );
Console::WriteLine();
}
private:
void serializer_UnknownNode( Object^ /*sender*/, XmlNodeEventArgs^ e )
{
Console::WriteLine( "Unknown Node:{0}\t{1}", e->Name, e->Text );
}
void serializer_UnknownAttribute( Object^ /*sender*/, XmlAttributeEventArgs^ e )
{
System::Xml::XmlAttribute^ attr = e->Attr;
Console::WriteLine( "Unknown attribute {0}='{1}'", attr->Name, attr->Value );
}
};
int main()
{
Test::main();
}
using System;
using System.Xml;
using System.Xml.Serialization;
using System.IO;
/* The XmlRootAttribute allows you to set an alternate name
(PurchaseOrder) of the XML element, the element namespace; by
default, the XmlSerializer uses the class name. The attribute
also allows you to set the XML namespace for the element. Lastly,
the attribute sets the IsNullable property, which specifies whether
the xsi:null attribute appears if the class instance is set to
a null reference. */
[XmlRootAttribute("PurchaseOrder", Namespace="http://www.cpandl.com",
IsNullable = false)]
public class PurchaseOrder
{
public Address ShipTo;
public string OrderDate;
/* The XmlArrayAttribute changes the XML element name
from the default of "OrderedItems" to "Items". */
[XmlArrayAttribute("Items")]
public OrderedItem[] OrderedItems;
public decimal SubTotal;
public decimal ShipCost;
public decimal TotalCost;
}
public class Address
{
/* The XmlAttribute instructs the XmlSerializer to serialize the Name
field as an XML attribute instead of an XML element (the default
behavior). */
[XmlAttribute]
public string Name;
public string Line1;
/* Setting the IsNullable property to false instructs the
XmlSerializer that the XML attribute will not appear if
the City field is set to a null reference. */
[XmlElementAttribute(IsNullable = false)]
public string City;
public string State;
public string Zip;
}
public class OrderedItem
{
public string ItemName;
public string Description;
public decimal UnitPrice;
public int Quantity;
public decimal LineTotal;
/* Calculate is a custom method that calculates the price per item,
and stores the value in a field. */
public void Calculate()
{
LineTotal = UnitPrice * Quantity;
}
}
public class Test
{
public static void Main()
{
// Read and write purchase orders.
Test t = new Test();
t.CreatePO("po.xml");
t.ReadPO("po.xml");
}
private void CreatePO(string filename)
{
// Create an instance of the XmlSerializer class;
// specify the type of object to serialize.
XmlSerializer serializer =
new XmlSerializer(typeof(PurchaseOrder));
TextWriter writer = new StreamWriter(filename);
PurchaseOrder po=new PurchaseOrder();
// Create an address to ship and bill to.
Address billAddress = new Address();
billAddress.Name = "Teresa Atkinson";
billAddress.Line1 = "1 Main St.";
billAddress.City = "AnyTown";
billAddress.State = "WA";
billAddress.Zip = "00000";
// Set ShipTo and BillTo to the same addressee.
po.ShipTo = billAddress;
po.OrderDate = System.DateTime.Now.ToLongDateString();
// Create an OrderedItem object.
OrderedItem i1 = new OrderedItem();
i1.ItemName = "Widget S";
i1.Description = "Small widget";
i1.UnitPrice = (decimal) 5.23;
i1.Quantity = 3;
i1.Calculate();
// Insert the item into the array.
OrderedItem [] items = {i1};
po.OrderedItems = items;
// Calculate the total cost.
decimal subTotal = new decimal();
foreach(OrderedItem oi in items)
{
subTotal += oi.LineTotal;
}
po.SubTotal = subTotal;
po.ShipCost = (decimal) 12.51;
po.TotalCost = po.SubTotal + po.ShipCost;
// Serialize the purchase order, and close the TextWriter.
serializer.Serialize(writer, po);
writer.Close();
}
protected void ReadPO(string filename)
{
// Create an instance of the XmlSerializer class;
// specify the type of object to be deserialized.
XmlSerializer serializer = new XmlSerializer(typeof(PurchaseOrder));
/* If the XML document has been altered with unknown
nodes or attributes, handle them with the
UnknownNode and UnknownAttribute events.*/
serializer.UnknownNode+= new
XmlNodeEventHandler(serializer_UnknownNode);
serializer.UnknownAttribute+= new
XmlAttributeEventHandler(serializer_UnknownAttribute);
// A FileStream is needed to read the XML document.
FileStream fs = new FileStream(filename, FileMode.Open);
// Declare an object variable of the type to be deserialized.
PurchaseOrder po;
/* Use the Deserialize method to restore the object's state with
data from the XML document. */
po = (PurchaseOrder) serializer.Deserialize(fs);
// Read the order date.
Console.WriteLine ("OrderDate: " + po.OrderDate);
// Read the shipping address.
Address shipTo = po.ShipTo;
ReadAddress(shipTo, "Ship To:");
// Read the list of ordered items.
OrderedItem [] items = po.OrderedItems;
Console.WriteLine("Items to be shipped:");
foreach(OrderedItem oi in items)
{
Console.WriteLine("\t"+
oi.ItemName + "\t" +
oi.Description + "\t" +
oi.UnitPrice + "\t" +
oi.Quantity + "\t" +
oi.LineTotal);
}
// Read the subtotal, shipping cost, and total cost.
Console.WriteLine("\t\t\t\t\t Subtotal\t" + po.SubTotal);
Console.WriteLine("\t\t\t\t\t Shipping\t" + po.ShipCost);
Console.WriteLine("\t\t\t\t\t Total\t\t" + po.TotalCost);
}
protected void ReadAddress(Address a, string label)
{
// Read the fields of the Address object.
Console.WriteLine(label);
Console.WriteLine("\t"+ a.Name );
Console.WriteLine("\t" + a.Line1);
Console.WriteLine("\t" + a.City);
Console.WriteLine("\t" + a.State);
Console.WriteLine("\t" + a.Zip );
Console.WriteLine();
}
private void serializer_UnknownNode
(object sender, XmlNodeEventArgs e)
{
Console.WriteLine("Unknown Node:" + e.Name + "\t" + e.Text);
}
private void serializer_UnknownAttribute
(object sender, XmlAttributeEventArgs e)
{
System.Xml.XmlAttribute attr = e.Attr;
Console.WriteLine("Unknown attribute " +
attr.Name + "='" + attr.Value + "'");
}
}
Imports System.Xml
Imports System.Xml.Serialization
Imports System.IO
' The XmlRootAttribute allows you to set an alternate name
' (PurchaseOrder) of the XML element, the element namespace; by
' default, the XmlSerializer uses the class name. The attribute
' also allows you to set the XML namespace for the element. Lastly,
' the attribute sets the IsNullable property, which specifies whether
' the xsi:null attribute appears if the class instance is set to
' a null reference.
<XmlRootAttribute("PurchaseOrder", _
Namespace := "http://www.cpandl.com", IsNullable := False)> _
Public Class PurchaseOrder
Public ShipTo As Address
Public OrderDate As String
' The XmlArrayAttribute changes the XML element name
' from the default of "OrderedItems" to "Items".
<XmlArrayAttribute("Items")> _
Public OrderedItems() As OrderedItem
Public SubTotal As Decimal
Public ShipCost As Decimal
Public TotalCost As Decimal
End Class
Public Class Address
' The XmlAttribute instructs the XmlSerializer to serialize the Name
' field as an XML attribute instead of an XML element (the default
' behavior).
<XmlAttribute()> _
Public Name As String
Public Line1 As String
' Setting the IsNullable property to false instructs the
' XmlSerializer that the XML attribute will not appear if
' the City field is set to a null reference.
<XmlElementAttribute(IsNullable := False)> _
Public City As String
Public State As String
Public Zip As String
End Class
Public Class OrderedItem
Public ItemName As String
Public Description As String
Public UnitPrice As Decimal
Public Quantity As Integer
Public LineTotal As Decimal
' Calculate is a custom method that calculates the price per item,
' and stores the value in a field.
Public Sub Calculate()
LineTotal = UnitPrice * Quantity
End Sub
End Class
Public Class Test
Public Shared Sub Main()
' Read and write purchase orders.
Dim t As New Test()
t.CreatePO("po.xml")
t.ReadPO("po.xml")
End Sub
Private Sub CreatePO(filename As String)
' Create an instance of the XmlSerializer class;
' specify the type of object to serialize.
Dim serializer As New XmlSerializer(GetType(PurchaseOrder))
Dim writer As New StreamWriter(filename)
Dim po As New PurchaseOrder()
' Create an address to ship and bill to.
Dim billAddress As New Address()
billAddress.Name = "Teresa Atkinson"
billAddress.Line1 = "1 Main St."
billAddress.City = "AnyTown"
billAddress.State = "WA"
billAddress.Zip = "00000"
' Set ShipTo and BillTo to the same addressee.
po.ShipTo = billAddress
po.OrderDate = System.DateTime.Now.ToLongDateString()
' Create an OrderedItem object.
Dim i1 As New OrderedItem()
i1.ItemName = "Widget S"
i1.Description = "Small widget"
i1.UnitPrice = CDec(5.23)
i1.Quantity = 3
i1.Calculate()
' Insert the item into the array.
Dim items(0) As OrderedItem
items(0) = i1
po.OrderedItems = items
' Calculate the total cost.
Dim subTotal As New Decimal()
Dim oi As OrderedItem
For Each oi In items
subTotal += oi.LineTotal
Next oi
po.SubTotal = subTotal
po.ShipCost = CDec(12.51)
po.TotalCost = po.SubTotal + po.ShipCost
' Serialize the purchase order, and close the TextWriter.
serializer.Serialize(writer, po)
writer.Close()
End Sub
Protected Sub ReadPO(filename As String)
' Create an instance of the XmlSerializer class;
' specify the type of object to be deserialized.
Dim serializer As New XmlSerializer(GetType(PurchaseOrder))
' If the XML document has been altered with unknown
' nodes or attributes, handle them with the
' UnknownNode and UnknownAttribute events.
AddHandler serializer.UnknownNode, AddressOf serializer_UnknownNode
AddHandler serializer.UnknownAttribute, AddressOf serializer_UnknownAttribute
' A FileStream is needed to read the XML document.
Dim fs As New FileStream(filename, FileMode.Open)
' Declare an object variable of the type to be deserialized.
Dim po As PurchaseOrder
' Use the Deserialize method to restore the object's state with
' data from the XML document.
po = CType(serializer.Deserialize(fs), PurchaseOrder)
' Read the order date.
Console.WriteLine(("OrderDate: " & po.OrderDate))
' Read the shipping address.
Dim shipTo As Address = po.ShipTo
ReadAddress(shipTo, "Ship To:")
' Read the list of ordered items.
Dim items As OrderedItem() = po.OrderedItems
Console.WriteLine("Items to be shipped:")
Dim oi As OrderedItem
For Each oi In items
Console.WriteLine((ControlChars.Tab & oi.ItemName & ControlChars.Tab & _
oi.Description & ControlChars.Tab & oi.UnitPrice & ControlChars.Tab & _
oi.Quantity & ControlChars.Tab & oi.LineTotal))
Next oi
' Read the subtotal, shipping cost, and total cost.
Console.WriteLine(( New String(ControlChars.Tab, 5) & _
" Subtotal" & ControlChars.Tab & po.SubTotal))
Console.WriteLine(New String(ControlChars.Tab, 5) & _
" Shipping" & ControlChars.Tab & po.ShipCost )
Console.WriteLine( New String(ControlChars.Tab, 5) & _
" Total" & New String(ControlChars.Tab, 2) & po.TotalCost)
End Sub
Protected Sub ReadAddress(a As Address, label As String)
' Read the fields of the Address object.
Console.WriteLine(label)
Console.WriteLine(ControlChars.Tab & a.Name)
Console.WriteLine(ControlChars.Tab & a.Line1)
Console.WriteLine(ControlChars.Tab & a.City)
Console.WriteLine(ControlChars.Tab & a.State)
Console.WriteLine(ControlChars.Tab & a.Zip)
Console.WriteLine()
End Sub
Private Sub serializer_UnknownNode(sender As Object, e As XmlNodeEventArgs)
Console.WriteLine(("Unknown Node:" & e.Name & ControlChars.Tab & e.Text))
End Sub
Private Sub serializer_UnknownAttribute(sender As Object, e As XmlAttributeEventArgs)
Dim attr As System.Xml.XmlAttribute = e.Attr
Console.WriteLine(("Unknown attribute " & attr.Name & "='" & attr.Value & "'"))
End Sub
End Class
注解
有关此 API 的详细信息,请参阅 XmlSerializer 的补充 API 说明。
构造函数
XmlSerializer() |
初始化 XmlSerializer 类的新实例。 |
XmlSerializer(Type) |
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 |
XmlSerializer(Type, String) |
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 指定所有 XML 元素的默认命名空间。 |
XmlSerializer(Type, Type[]) |
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 如果属性或字段返回一个数组,则 |
XmlSerializer(Type, XmlAttributeOverrides) |
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 要序列化的每个对象本身可包含类的实例,此重载可使用其他类重写这些实例。 |
XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String) |
初始化 XmlSerializer 类的新实例,该类可将 Object 类型的对象序列化为 XML 文档实例,并可将 XML 文档实例反序列化为 Object 类型的对象。 要序列化的每个对象本身可包含类的实例,此重载可使用其他类重写这些实例。 此重载还指定所有 XML 元素的默认命名空间和用作 XML 根元素的类。 |
XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String, String) |
初始化 XmlSerializer 类的新实例,该类可将 Object 类型的对象序列化为 XML 文档实例,并可将 XML 文档实例反序列化为 Object 类型的对象。 要序列化的每个对象本身可包含类的实例,此重载可使用其他类重写这些实例。 此重载还指定所有 XML 元素的默认命名空间和用作 XML 根元素的类。 |
XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String, String, Evidence) |
已过时.
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 此重载允许您提供在序列化或反序列化操作过程中可能遇到的其他类型;还允许您提供所有 XML 元素的默认命名空间,作为 XML 根元素使用的类,类的位置和访问所需的凭据。 |
XmlSerializer(Type, XmlRootAttribute) |
初始化 XmlSerializer 类的新实例,该类可以将指定类型的对象序列化为 XML 文档,也可以将 XML 文档反序列化为指定类型的对象。 还可以指定作为 XML 根元素使用的类。 |
XmlSerializer(XmlTypeMapping) |
使用将一个类型映射到另一个类型的对象来初始化 XmlSerializer 类的实例。 |
方法
事件
UnknownAttribute |
当 XmlSerializer 在反序列化过程中遇到未知类型的 XML 特性时发生。 |
UnknownElement |
当 XmlSerializer 在反序列化过程中遇到未知类型的 XML 元素时发生。 |
UnknownNode |
当 XmlSerializer 在反序列化过程中遇到未知类型的 XML 节点时发生。 |
UnreferencedObject |
在反序列化 SOAP 编码的 XML 流的过程中发生,此时 XmlSerializer 遇到未使用(或未引用)的识别类型。 |
适用于
线程安全性
此类型是线程安全的。