转换为 Mock 需要接口。无法 Xml 序列化

Question

我正在转换一个项目，以便可以使用 Moq (Mock) 测试。

我有一个具有接口列表的类。我了解接口无法序列化。所以我正在努力解决它。

在尝试了其他 SO 帖子（Serializing a List hold an interface to XML、XmlSerializer serialize generic List of interface）的多种方法之后，我创建了一个控制台进行测试；我觉得我需要寻求帮助。

下面的示例代码将 List 包装在自己的类中，以便能够实现 ISerializable 接口。但是，我有以下总结错误：

Cannot serialize member MyConcreteCollection.ChildList of type IChild because 
it is an interface.

问题出在这段代码中

public void WriteXml(System.Xml.XmlWriter writer)
{
    //-- HAVE also tried IChild child in ChildList
    foreach (ConcreteChild child in ChildList)
    {
        XmlSerializer s = new XmlSerializer(child .GetType());
        s.Serialize(writer, child );
    }
}

这里是完整的代码列表。这是有效的，并由用户 Jay 实施了修复

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using System.IO;

[Serializable]
public class ConcreteParent
{
    public MyConcreteCollection MyConcreteCollection { get; set; }
}

[Serializable]
public class MyConcreteCollection : IXmlSerializable //(Was ISerializable, as fixed by user Jay)
{
    public List<IChild> ChildList { get; set; }

    public System.Xml.Schema.XmlSchema GetSchema() { return null; }
    public void ReadXml(System.Xml.XmlReader reader) { }
    public void GetObjectData(SerializationInfo info, StreamingContext context) { }

    public void WriteXml(System.Xml.XmlWriter writer)
    {
        foreach (ConcreteChild child in ChildList)
        {
            XmlSerializer s = new XmlSerializer(child.GetType());
            s.Serialize(writer, child);
        }
    }

}

public interface IChild { }
[Serializable] public class ConcreteChild : IChild { }


public static class SerializerHelper<T>
{
    public static string Serialize(T myobject)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
        StringWriter stringWriter = new StringWriter();
        xmlSerializer.Serialize(stringWriter, myobject);
        string xml = stringWriter.ToString();

        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.LoadXml(xml);
        StringWriter sw = new StringWriter();
        XmlTextWriter xw = new XmlTextWriter(sw);
        xmlDoc.WriteTo(xw);

        return sw.ToString();
    }
}

class Program
{
    static void Main(string[] args)
    {
        try
        {
            ConcreteParent concreteParent = new ConcreteParent();
            concreteParent.MyConcreteCollection = new MyConcreteCollection();
            concreteParent.MyConcreteCollection.ChildList = new List<IChild>();
            concreteParent.MyConcreteCollection.ChildList.Add(new ConcreteChild());

            string xml = SerializerHelper<ConcreteParent>.Serialize(concreteParent);
            Console.WriteLine(xml);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.ToString());
        }
        Console.ReadKey();
    }
}

Answer 1

您有 MyConcreteCollection 实现 ISerializable。如您链接到的第一篇文章所示，您需要实现 IXmlSerializable。