KnownTypeAttribute.MethodName Property

Definition

Namespace:

System.Runtime.Serialization

Assemblies:

netstandard.dll, System.Runtime.Serialization.Primitives.dll

Source:

KnownTypeAttribute.cs

Gets the name of a method that will return a list of types that should be recognized during serialization or deserialization.

C#

public string? MethodName { get; }

Property Value

String

A String that contains the name of the method on the type defined by the KnownTypeAttribute class.

Examples

The following example uses the methodName parameter to identify a method in the type that contains an array of Type objects.

C#

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();
        }
    }
}

Remarks

The method must exist on the class or structure that the KnownTypeAttribute is applied to, must be static, must accept no parameters, and must return an instance of any type that implements the generic IEnumerable<T> interface, such as the Collection<T> class, or an array of Type objects.

The method is called once per application domain when the data contract is loaded for the type.

Applies to