KnownTypeAttribute.MethodName 属性

定义

命名空间:

System.Runtime.Serialization

程序集:

System.Runtime.Serialization.Primitives.dll

Source:

KnownTypeAttribute.cs

获取能够返回在序列化或反序列化过程中应识别的类型列表的方法名称。

public:
 property System::String ^ MethodName { System::String ^ get(); };

public string? MethodName { get; }

member this.MethodName : string

Public ReadOnly Property MethodName As String

属性值

String

一个 String，它包含 KnownTypeAttribute 类所定义的类型上的方法的名称。

示例

下面的示例使用 methodName 参数标识包含 Type 对象数组的类型中的方法。

namespace KnownTypeAttributeExample
{
    using System;
    using System.Xml;
    using System.Collections.Generic;
    using System.Text;
    using System.Runtime.Serialization;
    using System.IO;
    // The constructor names the method that returns an array
    // of types that can be used during deserialization.
    [KnownTypeAttribute("KnownTypes")]
    [DataContract]
    public class Employee
    {
        public Employee(string newFName, string newLName)
        {
            FirstName = newFName;
            LastName = newLName;
        }
        [DataMember]
        internal string FirstName;
        [DataMember]
        internal string LastName;
        [DataMember]
        internal int id;
        [DataMember]
        internal Manager Boss;

        // This method returns the array of known types.
        static Type[] KnownTypes()
        {
            return new Type[]{typeof(Manager), typeof(Employee)};
        }
    }

    [DataContract]
    public class Manager : Employee
    {
        // Call the base class's constructor.
        public Manager(string newFName, string newLName)
            : base(newFName, newLName)
        { }

        [DataMember]
        internal Employee[] Reports;
    }

    class Program
    {
        public static void Main()
        {
            try
            {
                Serialize("person1.xml");
                Deserialize("person1.xml");
            }
            catch (SerializationException se)
            {
                Console.WriteLine("{0}: {1}",
                se.Message, se.StackTrace);
            }
            finally
            {
                Console.WriteLine("Press Enter to exit....");
                Console.ReadLine();
            }
        }

        static void Serialize(string path)
        {
            Employee emp = new Employee("John", "Peoples");
            emp.id = 3001;
            Manager theBoss = new Manager("Michiyo", "Sato");
            theBoss.id = 41;
            emp.Boss = theBoss;

            DataContractSerializer ser =
                new DataContractSerializer(typeof(Employee));

            FileStream fs =
                new FileStream(path, FileMode.OpenOrCreate);
            ser.WriteObject(fs, emp);
            fs.Close();
        }
        static void Deserialize(string path)
        {
            DataContractSerializer ser =
                new DataContractSerializer(typeof(Employee));
            FileStream fs = new FileStream(path,
            FileMode.Open);
            Employee p = (Employee)ser.ReadObject(fs);

            Console.WriteLine("{0} {1}, id:{2}", p.FirstName,
                p.LastName, p.id);
            fs.Close();
        }
    }
}

' The constructor names the method that returns an array 
' of types that can be used during deserialization.
<KnownTypeAttribute("KnownTypes"), DataContract()>  _
Public Class Employee
    Public Sub New(ByVal newFName As String, ByVal newLName As String) 
        FirstName = newFName
        LastName = newLName
    
    End Sub
    <DataMember()>  _
    Friend FirstName As String
    <DataMember()>  _
    Friend LastName As String
    <DataMember()>  _
    Friend id As Integer
    <DataMember()>  _
    Friend Boss As Manager
    
    ' This method returns the array of known types.
    Shared Function KnownTypes() As Type() 
        Return New Type() {GetType(Manager), GetType(Employee)}
    
    End Function 
End Class 

<DataContract()>  _
Public Class Manager
    Inherits Employee
    
    ' Call the base class's constructor.
    Public Sub New(ByVal newFName As String, ByVal newLName As String) 
        MyBase.New(newFName, newLName)
    
    End Sub 
    
    <DataMember()>  _
    Friend Reports() As Employee
End Class 

Class Program

    Public Shared Sub Main() 
        Try
            Serialize("person1.xml")
            Deserialize("person1.xml")
        Catch se As SerializationException
            Console.WriteLine("{0}: {1}", se.Message, se.StackTrace)
        Finally
            Console.WriteLine("Press Enter to exit....")
            Console.ReadLine()
        End Try
    
    End Sub 
    
    Shared Sub Serialize(ByVal path As String) 
        Dim emp As New Employee("John", "Peoples")
        emp.id = 3001
        Dim theBoss As New Manager("Michiyo", "Sato")
        theBoss.id = 41
        emp.Boss = theBoss

        Dim ser As New DataContractSerializer(GetType(Employee))
        
        Dim fs As New FileStream(path, FileMode.OpenOrCreate)
        ser.WriteObject(fs, emp)
        fs.Close()
    
    End Sub 
    
    Shared Sub Deserialize(ByVal path As String) 
        Dim ser As New DataContractSerializer(GetType(Employee))
        Dim fs As New FileStream(path, FileMode.Open)
        Dim p As Employee = CType(ser.ReadObject(fs), Employee)
        
        Console.WriteLine("{0} {1}, id:{2}", p.FirstName, p.LastName, p.id)
        fs.Close()
    
    End Sub 
End Class

注解

该方法必须存在于应用了 KnownTypeAttribute 的类或结构中，必须为静态方法，必须不采用任何参数，并且必须返回任何实现了 IEnumerable<T> 泛型接口的类型（如 Collection<T> 类）的实例或 Type 对象数组。

在加载该类型的数据协定时，将针对每个应用程序域调用该方法一次。