Protobuf 继承和泛型

Question

我正在尝试使用 ProtoBuf 网络来序列化具有以下格式的类的对象树：

[ProtoContract]
class MySpecialCollectionList<T> : List<MySpecialCollection<T>>
{
    [ProtoMember(1)]
    public string Name { get; set; }
}

[ProtoContract]
class MySpecialCollection<T> : List<Special<T>>
{
    [ProtoMember(1)]
    public string Name { get; set; }
}

[ProtoContract]
class Special<T>
{
    [ProtoMember(1)]
    public string Name { get; set; }
    [ProtoMember(2)]
    public string Description { get; set; }

    [ProtoMember(3)]
    private readonly T _source; 
    T Source { get { return _source; } }

    private Special()
    {
    }

    public Special(T source) 
    { 
        _source = source; 
    }
}

interface IBeast
{
    string Name { get; set; }
}
[ProtoContract]
class Ant : IBeast
{
    [ProtoMember(1)]
    public string Name { get; set; }
}
[ProtoContract]
class Cat : IBeast
{
    [ProtoMember(1)]
    public string Name { get; set; }
}
[ProtoContract]
class Dog : IBeast
{
    [ProtoMember(1)]
    public string Name { get; set; }
}

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        MySpecialCollectionList<IBeast> collectionList = GetSpecialCollectionList();
        using (var fs = File.Create(@"c:\temp\protobuftest.bin"))
        {
            Serializer.Serialize(fs, collectionList);

            fs.Close();
        }
    }

    private MySpecialCollectionList<IBeast> GetSpecialCollectionList()
    {
        var ant = new Ant() { Name = "Mr Ant" };
        var cat = new Cat() { Name = "Mr Cat" };
        var dog = new Dog() { Name = "Mr Dog" };

        var Special = new Special<IBeast>(ant);

        var specialCollection1 = new MySpecialCollection<IBeast>() {
            {new Special<IBeast>(ant)},
            {new Special<IBeast>(cat)},
            {new Special<IBeast>(dog)}
        };
        specialCollection1.Name = "Special Collection1";


        var specialCollection2 = new MySpecialCollection<IBeast>() {
            {new Special<IBeast>(ant)},
            {new Special<IBeast>(dog)}
        };
        specialCollection2.Name = "Special Collection2";

        var specialCollectionList = new MySpecialCollectionList<IBeast>() {
            specialCollection1, specialCollection2 };

        specialCollectionList.Name = "Special Collection List";
        return specialCollectionList;
    }
}

注意我正在序列化的类 (MySpecialCollectionList<T>) 是如何从 List<SomeOtherClass<T>> 派生的，而不仅仅是 List<T>。

我正在努力找出在哪里放置“ProtoInclude”属性以使其序列化 MySpecialCollectionList 中的所有项目。任何帮助将不胜感激。

Answer 1

这里的继承不是问题，因为即使A : B 也不是Foo<A> : Foo<B>。请注意，protobuf-net 不会使用非默认构造函数，尽管可以跳过构造函数，直接绑定到字段（甚至readonly）。虽然您可能有 6 个T，但我无法（从代码中）看出您想要使用哪种封闭类型，如果已知封闭类型，则应该设置它。

如果你有一个Foo<SomeBaseClass> 和一些从SomeBaseClass 继承的具体类型，那么标记将在SomeBaseClass 上。

但是，如果您有一个具体的场景可以用来重现您的问题，我会很乐意看看。

---

更新重新编辑：

示例中引出了几个关键点：

• 与大多数绑定 API、XmlSerializer 和 IIRC DataContractSerializer 一样，项目是任一列表xor具有值的项目；如果一个集合（实现IList的东西）本身有属性，它们将不会被序列化； encapsulation 在此优先于继承，即 具有 Name 并且 具有 列表（而不是 具有 一个Name 和是一个列表）
• protobuf-net v1 不支持基于接口的序列化； v2 确实，但与 XmlSerializer 和 DataContractSerializer 一样，您需要明确告诉它它需要期待什么；不过，非常好，我们可以将[ProtoMember] 移动到界面本身上

这是 v2 中的完整版本：

using System.Collections.Generic;
using ProtoBuf;
[ProtoContract]
class MySpecialCollectionList<T>
{
    [ProtoMember(1)]
    public string Name { get; set; }

    private readonly List<MySpecialCollection<T>> items = new List<MySpecialCollection<T>>();
    [ProtoMember(2)]
    public List<MySpecialCollection<T>> Items { get { return items; } }
}

[ProtoContract]
class MySpecialCollection<T>
{
    [ProtoMember(1)]
    public string Name { get; set; }

    private readonly List<Special<T>> items = new List<Special<T>>();
    [ProtoMember(2)]
    public List<Special<T>> Items { get { return items; } }
}

[ProtoContract]
class Special<T>
{
    [ProtoMember(1)]
    public string Name { get; set; }
    [ProtoMember(2)]
    public string Description { get; set; }

    [ProtoMember(3)]
    private readonly T _source;
    T Source { get { return _source; } }

    private Special()
    {
    }

    public Special(T source)
    {
        _source = source;
    }
}
[ProtoContract]
[ProtoInclude(2, typeof(Ant))]
[ProtoInclude(3, typeof(Cat))]
[ProtoInclude(4, typeof(Dog))]
interface IBeast
{
    [ProtoMember(1)]
    string Name { get; set; }
}
[ProtoContract]
class Ant : IBeast
{
    public string Name { get; set; }
}
[ProtoContract]
class Cat : IBeast
{
    public string Name { get; set; }
}
[ProtoContract]
class Dog : IBeast
{
    public string Name { get; set; }
}

public static class Form1
{

    private static void Main()
    {
        MySpecialCollectionList<IBeast> collectionList = GetSpecialCollectionList();
        var copy = Serializer.DeepClone(collectionList);
    }

    private static MySpecialCollectionList<IBeast> GetSpecialCollectionList()
    {
        var ant = new Ant() { Name = "Mr Ant" };
        var cat = new Cat() { Name = "Mr Cat" };
        var dog = new Dog() { Name = "Mr Dog" };

        var Special = new Special<IBeast>(ant);

        var specialCollection1 = new MySpecialCollection<IBeast>() {Items =
            {new Special<IBeast>(ant),
            new Special<IBeast>(cat),
            new Special<IBeast>(dog)}
        };
        specialCollection1.Name = "Special Collection1";


        var specialCollection2 = new MySpecialCollection<IBeast>()
        {
            Items =
            {new Special<IBeast>(ant),
            new Special<IBeast>(dog)}
        };
        specialCollection2.Name = "Special Collection2";

        var specialCollectionList = new MySpecialCollectionList<IBeast>()
        {
            Items ={
            specialCollection1, specialCollection2 }
        };

        specialCollectionList.Name = "Special Collection List";
        return specialCollectionList;
    }
}