XmlSerializer 類別
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
將物件序列化與反序列化，進出 XML 文件。 這 XmlSerializer 讓你能控制物件如何編碼成 XML。
public ref class XmlSerializerpublic class XmlSerializertype XmlSerializer = classPublic Class XmlSerializer- 繼承
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XmlSerializer
範例
以下範例包含兩個主要類別： PurchaseOrder 和 Test。 該 PurchaseOrder 類別包含單一購買的資訊。 這個 Test 類別包含建立採購單的方法，以及讀取已建立的採購單的方法。
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
備註
欲了解更多關於此 API 的資訊，請參閱 XmlSerializer 的補充 API 備註。
建構函式
| 名稱 | Description |
|---|---|
| XmlSerializer() |
初始化 XmlSerializer 類別的新執行個體。 |
| XmlSerializer(Type, String) |
初始化該類別的新實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件，並將 XML 文件反序列化為指定類型的物件。 指定所有 XML 元素的預設命名空間。 |
| XmlSerializer(Type, Type[]) |
初始化一個新的類別實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件，並將 XML 文件反序列化為指定類型的物件。 如果某個屬性或欄位回傳陣列，該 |
| XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String, String, Evidence) |
已淘汰.
初始化該類別的新實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件實例，並將 XML 文件實例反序列化為指定類型的物件。 這種過載讓你能提供序列化或反序列化操作中可能遇到的其他類型，以及所有 XML 元素的預設命名空間、用作 XML 根元素的類別、其位置，以及存取所需的憑證。 |
| XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String, String) |
初始化該類別的新實例，該實例 XmlSerializer 能將 類型的 Object 物件序列化為 XML 文件實例，並將 XML 文件實例反序列化為型別 Object為 的物件。 每個待序列化的物件本身可以包含類別的實例，這種過載會用其他類別覆蓋這些類別。 此過載同時指定所有 XML 元素的預設命名空間，以及作為 XML 根元素的類別。 |
| XmlSerializer(Type, XmlAttributeOverrides, Type[], XmlRootAttribute, String) |
初始化該類別的新實例，該實例 XmlSerializer 能將 類型的 Object 物件序列化為 XML 文件實例，並將 XML 文件實例反序列化為型別 Object為 的物件。 每個待序列化的物件本身可以包含類別的實例，這種過載會用其他類別覆蓋這些類別。 此過載同時指定所有 XML 元素的預設命名空間，以及作為 XML 根元素的類別。 |
| XmlSerializer(Type, XmlAttributeOverrides) |
初始化該類別的新實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件，並將 XML 文件反序列化為指定類型的物件。 每個待序列化的物件本身可以包含類別的實例，這種過載可以用其他類別覆蓋這些類別。 |
| XmlSerializer(Type, XmlRootAttribute) |
初始化該類別的新實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件，並將 XML 文件反序列化為指定類型的物件。 它也指定了作為 XML 根元素的類別。 |
| XmlSerializer(Type) |
初始化該類別的新實例，該實例 XmlSerializer 能將指定類型的物件序列化為 XML 文件，並將 XML 文件反序列化為指定類型的物件。 |
| XmlSerializer(XmlTypeMapping) |
使用一個將一個類型映射到另一個類型的物件來初始化該 XmlSerializer 類別的實例。 |
方法
事件
| 名稱 | Description |
|---|---|
| UnknownAttribute |
當在 XmlSerializer 反序列化過程中遇到未知類型的 XML 屬性時，會發生這種情況。 |
| UnknownElement |
當在 XmlSerializer 反序列化過程中遇到未知類型的 XML 元素時，會發生這種情況。 |
| UnknownNode |
當在 XmlSerializer 反序列化過程中遇到未知類型的 XML 節點時，會發生這種情況。 |
| UnreferencedObject |
發生在 SOAP 編碼的 XML 串流反序列化時，當遇到 XmlSerializer 未被使用或未被引用的已識別型態時。 |
適用於
執行緒安全性
此類型是安全線程。
