在具有匿名方法的类上使用XmlSerializer

Question

I want to serialize a class which uses an anonymous function in its implementation. The compiler is generating an inner class to implement the anonymous function. The serializer fails with the error: "MyClass+<>c__DisplayClass2 is inaccessible due to its protection level. Only public types can be processed."

public class MyClass {
    public doIt() {
        int objective = 0;
        return List<int> () { 1 }.Any(i => i == objective);
    }
}

new XmlSerializer(typeof(MyClass)).Serialize(writer, myClass);

How do I serialize this class? Thanks.

Answer 1

I cannot reproduce this exception with C# 3.0 and .NET 3.5 SP1 -- which tool-set are you using?

Note that the XmlSerializer doesn't serialize methods; only values and properties. Are you using another serializer by chance? If so, place the SerializableAttribute on the class definition as follows.

[Serializable]
public class MyClass{ ... }

Here is the code I used to try to reproduce your issue, which is semantically equivalent.

public class MyClass
{
    public bool doIt()
    {
        int objective = 0;
        return new List<int>() { 1 }.Any(i => i == objective);
    }
}

static class Program
{
    static void Main(string[] args)
    {
        new XmlSerializer(typeof(MyClass)).Serialize(new MemoryStream(), new MyClass());        
    }
}

Answer 2

Instead of returning a List, you should make a new class marked serializable and send that.

[Serializable]
class MyList : List<int>
{
}

Answer 3

如果您不希望序列化下来，请使用XMLIgnore属性标记doIt方法。