如何序列化從非泛型 class 繼承的泛型類型列表

Question

我有一個 class 結構如下：

[Serializable]
public abstract class TagConfiguration
{
    public abstract string Name { get; set; }

    // Other abstract properties

    public abstract object GetInitialValue();
    public abstract void SetInitialValue(object value);

    protected TagConfiguration() { }

    // Other methods not useful in the scope of this problem
}

[Serializable]
public class GenericTagConfiguration<T> : TagConfiguration
{
    public override string Name { get; set; }

    // Other abstract properties

    private T _initialValue;
    public T InitialValue
        {
            get => (T)GetInitialValue();
            set => SetInitialValue(value);
        }
        public override object GetInitialValue()
        {
            return _initialValue;
        }
        public override void SetInitialValue(object value)
        {
            _initialValue = (T)value;
        }

    public GenericTagConfiguration() : base() { }

    // Other methods not useful in the scope of this problem
}

這個 class，顧名思義是用於配置一個標簽 object，如下所示：

[Serializable]
public abstract class Tag
{
    public abstract object GetConfiguration();
    public abstract void SetConfiguration(object value);
    public abstract object GetCurrentValue();
    public abstract void SetCurrentValue(object value);

    protected Tag() { }

    // Some abstract methods
}

[Serializable]
public class GenericTag<T> : Tag
{
    private GenericTagConfiguration<T> _configuration;
    public TagConfiguration Configuration
    {
        get => (GenericTagConfiguration<T>)GetConfiguration();
        set => SetConfiguration(value);
    }
    public override object GetConfiguration()
    {
        return _configuration;
    }
    public override void SetConfiguration(object value)
    {
        _configuration = (GenericTagConfiguration<T>)value;
    }

    private T _currentValue;
    public T CurrentValue
    {
        get => (T)GetCurrentValue();
        set => SetCurrentValue(value);
    }
    public override object GetCurrentValue()
    {
        return _currentValue;
    }
    public override void SetCurrentValue(object value)
    {
        _currentValue = (T)value;
    }

    public GenericTag() : base() { }

    // The same methods from Tag overridden
}

我必須能夠將List<TagConfiguration>導出到 XML 文件，但我遇到的問題是每當我嘗試這樣做時，都會收到一條錯誤消息：

Unhandled Exception: System.InvalidOperationException: There was an error generating the XML document. 
---> System.InvalidOperationException:The type GenericTagConfiguration[[System.Int32]] was not expected. 
Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

我正在使用以下代碼嘗試導出：

List<TagConfiguration> lstTagConf = new List<TagConfiguration>
{
    tagConf,
    tagConf2
};

XmlSerializer xs = new XmlSerializer(typeof(List<TagConfiguration>));
using (TextWriter tw = new StreamWriter(@"C:\Users\Administrator\Documents\listTag.xml"))
{
    xs.Serialize(tw, lstTagConf);
}

問題

我添加Tag class 的原因是我需要能夠導入和導出List<Tag>以及List<TagConfiguration> 。

我需要編寫一個接口來執行此操作嗎？

Answer 1

我找到的答案（感謝jdweng和這個問題）是在TagConfiguration class 之前添加以下內容：

[XmlInclude(typeof(GenericTagConfiguration<int>)), ...] // as many different T as you would use
[Serializable]
public abstract class TagConfiguration
{
    // Same data
}