如何序列化包含基本类型和基本类型数组的元组？

Question

在 C# 4.0 中，我尝试使用 DataContractSerializer 序列化和反序列化 Tuple<Guid, int[]>。我已经成功序列化和反序列化类型Guid、类型int[] 和类型Tuple<Guid, int>。如果我尝试序列化类型Tuple<Guid, int[]>，一切都会编译，但会出现以下运行时异常：

Type 'System.Int32[]' with data contract name 
'ArrayOfint:http://schemas.microsoft.com/2003/10/Serialization/Arrays'
is not expected. Consider using a DataContractResolver or add any types
not known statically to the list of known types - for example, by using
the KnownTypeAttribute attribute or by adding them to the list of known 
types passed to DataContractSerializer.

我的序列化和反序列化例程很简单：

public static string Serialize<T>(this T obj)
{
    var serializer = new DataContractSerializer(obj.GetType());
    using (var writer = new StringWriter())
    using (var stm = new XmlTextWriter(writer))
    {
        serializer.WriteObject(stm, obj);
        return writer.ToString();
    }
}

public static T Deserialize<T>(this string serialized)
{
    var serializer = new DataContractSerializer(typeof(T));
    using (var reader = new StringReader(serialized))
    using (var stm = new XmlTextReader(reader))
    {
        return (T)serializer.ReadObject(stm);
    }
}

为什么我会收到此异常，我可以做些什么来解决或绕过它？在我看来，包含可序列化类型的 Tuple 应该不会有序列化问题。

Answer 1

这样的事情怎么样？

class Program
{
    public static class DataContractSerializerFactory<T>
    {
        private static IEnumerable<Type> GetTypeArguments(Type t, IEnumerable<Type> values)
        {
            if (t.IsGenericType)
                foreach (var arg in t.GetGenericArguments())
                    values = values.Union(GetTypeArguments(arg, values));
            else
                values = values.Union(new[] { t });
            return values;
        }

        public static DataContractSerializer Create()
        {
            return new DataContractSerializer(typeof(T), GetTypeArguments(typeof(T), new[] { typeof(T) }));
        }
    }

    static void Main(string[] args)
    {
        var x = Tuple.Create(Guid.NewGuid(), new[] { 1, 2, 3, 4, 5, 6 });

        var serializer = DataContractSerializerFactory<Tuple<Guid, int[]>>.Create();

        var sb = new StringBuilder();
        using (var writer = XmlWriter.Create(sb))
        {
            serializer.WriteObject(writer, x);
            writer.Flush();
            Console.WriteLine(sb.ToString());
        }
    }
}

编辑：应该适用于任何嵌套泛型。仅考虑基本类型和叶类型参数。如果您希望中间容器也成为 KnownTypes 的一部分，这应该很容易。

Answer 2

错误信息告诉你需要做什么；问题在于，本身是嵌入在序列化类型中的成员的数组不会立即被序列化程序识别。您只需为其提供序列化该特定类型所需的元数据。

通常你会通过在DataContact 上添加一个属性来做到这一点，如下所示：

[DataContract]
[KnownType(typeof(int[]))]

但是由于您要序列化 ​​Tuple 而不是用户定义的类，因此您需要将其传递给 the constructor:

var knownTypes = new List<Type> { typeof(int[]) };
var serializer = new DataContractSerializer(typeof(Tuple<Guid, int[]>), knownTypes);