如何使用通用属性序列化/反序列化类？

Question

I'm unable to deserialise a class containing a generic property T. The exception I get is:

Unable to generate a temporary class (result=1). error CS0030: Cannot convert type 'Teacher' to 'Programmer' error CS0029: Cannot implicitly convert type 'Programmer' to 'Teacher'

A contrived example of my class structure is:

[Serializable]
public class Person<T> where T : Profession
{
    [XmlElement("Teacher", typeof(Teacher))]
    [XmlElement("Programmer", typeof(Programmer))]
    public T Profession { get; set; }
}

[Serializable]
[XmlInclude(typeof(Teacher))] // A Subclass
[XmlInclude(typeof(Programmer))] // A Subclass
public class Profession
{}

[Serializable]
public class Teacher : Profession
{
    [XmlElement]
    public int Salary { get; set; }
}


[Serializable]
public class Programmer : Profession
{
    [XmlElement]
    public long MassiveSalary { get; set; }
}

The structure of the XML file I want to deserialise is:

<Person>
    <Programmer/>
</Person>

or could be ...

<Person>
    <Teacher />
</Person>

Essentially the same problem is described here but the solution/workaround used doesn't make sense to me. In that case the workaround was to define an implicit conversion between the different types (Teacher/Programmer in this example).

One final point is that if I comment out either of the professions, then I can deserialize at least one version of the file. For example:

[Serializable]
public class Person<T> where T : Profession
{
    // Comment out 'Programmer' and I can deserialise all files with a 'Teacher' XMLElement
    [XmlElement("Teacher", typeof(Teacher))]
    //[XmlElement("Programmer", typeof(Programmer))]

    public T Profession { get; set; }
}

Then it becomes possible to deserialise the file. Can anyone explain whether or not it is possible to do this, or suggest a reasonable workound? Thanks.

Answer 1

Try following xml linq :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq; 

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string xml =
                "<Root>" +
                   "<Person>" +
                      "<Programmer/>" +
                      "<Teacher/>" +
                   "</Person>" +
                "</Root>";

            XElement root = XElement.Parse(xml);

            string[] persons = root.Descendants("Person").Elements().Select(x => x.Name.LocalName).ToArray();
        }
    }
}