反映类型时出现错误 - XML 序列化问题

Question

我有一个需要写入 XML 文件的 Dictionary 对象。 字典包含字符串类型作为键和自定义类的对象（派生自 System.Windows.Forms.Control ）作为值。

namespace SharpFormEditorDemo
{
    [Serializable]
    public static class common
    {

    public static Dictionary<String,CommonControl > dicControls = new Dictionary<string, CommonControl>();

    public static Object objSelected = new Object();
    public static int ctrlId = 0;

    //The serialization and Deserialization methods.
    public static void Serialize(XmlTextWriter xmlTextWriter,Dictionary<String,CommonControl> dic)
    {
        xmlTextWriter.WriteStartDocument();
        ControlSerializer file = new ControlSerializer(dic);
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(ControlSerializer));
        xmlSerializer.Serialize(xmlTextWriter, file);

        xmlTextWriter.WriteEndDocument();
    }
}

CommonControl类是这样的

namespace SharpFormEditorDemo
{

public class CommonControl : System.Windows.Forms.Control 
{

    //private List<String> controls;
    private String sql;
    private int minVal; //Minimum value for a field
    private int maxVal; //Maximum value for a field
    private string displayValue; //Display Value        
    private string keyValue; //Key Value
    private string clickEvent; //Click event
    private string selectedIndexChangeEvent; //Combo box event.
    private string validateEvent; //Validated event.



    public string SelectedIndexChangeEvent
    {
        get { return selectedIndexChangeEvent; }
        set { selectedIndexChangeEvent = value; }
    }

    public string ClickEvent
    {
        get { return clickEvent; }
        set { clickEvent = value; }
    }

    public string ValidateEvent
    {
        get { return validateEvent; }
        set { validateEvent = value; }
    }

    public string KeyValue
    {
        get { return keyValue; }
        set { keyValue = value; }
    }

    public string DisplayValue
    {
        get { return displayValue; }
        set { displayValue = value; }
    }

    public int MinVal
    {
        get { return minVal; }
        set { minVal = value; }
    }       

    public int MaxVal
    {
        get { return maxVal; }
        set { maxVal = value; }
    }     

    public String Sql
    {
        get { return sql; }
        set { sql = value; }
    }

    //public List<String> Controls
    //{
    //    get { return controls; }
    //    set { controls = value; }
    //}
}
}

CommonControl 类是 Controls 类的派生类。

我想要做的是将上述字典写入 XML 文件。

[Serializable]
public class ControlSerializer : ISerializable
{
    public ControlSerializer()
    {
    }


    private Dictionary<String, CommonControl> dicCtrl;

    public Dictionary<String, CommonControl> DicCtrl
    {
        get { return dicCtrl; }
        set { dicCtrl = value; }
    }


    public ControlSerializer(Dictionary<String, CommonControl> dic)
    {           
        this.DicCtrl = dic;
    }

    public void GetObjectData(SerializationInfo info, StreamingContext context)
    {
        throw new NotImplementedException();
    }

}

为此，我正在使用 ControlSerializer 类

这样称呼它

 try
        {
            XmlTextWriter xlw = new XmlTextWriter(@"D:\Test.xml", null);
            common.Serialize(xlw, common.dicControls);
        }
        catch (Exception exShow)
        {

问题是我得到一个例外说 “反映类型 'SharpFormEditorDemo.ControlSerializer' 时出现错误。”

但我使用 typeof 运算符获取类型。对为什么会发生这种情况感到困惑。对不起，如果我太长了，但想给出完整的图片。

谢谢

Answer 1

不能对通用字典进行 XmlSerialized。你得到的错误是由公共属性DicCtrl引起的。

• 序列化时使用[XmlIgnore] 属性跳过此属性（这可能不是您想要的）。
• 将属性的类型更改为可以序列化的类型，例如List<T>
• 查找或实现可序列化字典
• 或者实现IXmlSerializable

顺便说一句，[Serializable] 属性仅用于二进制序列化。 Xml 序列化不需要它。

Answer 2

伙计们..在网络上的一些帮助下，我找到了解决方案..

我不得不添加另一个类

[XmlRoot("dictionary")]
public class SerializableDictionary<TKey, TValue>: Dictionary<TKey, TValue>, IXmlSerializable
{      

    #region IXmlSerializable Members
    public System.Xml.Schema.XmlSchema GetSchema()
    {
        return null;
    }


    public void ReadXml(System.Xml.XmlReader reader)
    {
        XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
        XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); 

        bool wasEmpty = reader.IsEmptyElement;
        reader.Read(); 

        if (wasEmpty)
            return; 

        while (reader.NodeType != System.Xml.XmlNodeType.EndElement)
        {
            reader.ReadStartElement("item");
            reader.ReadStartElement("key");
            TKey key = (TKey)keySerializer.Deserialize(reader);
            reader.ReadEndElement();
            reader.ReadStartElement("value");
            TValue value = (TValue)valueSerializer.Deserialize(reader);
            reader.ReadEndElement();
            this.Add(key, value);
            reader.ReadEndElement();
            reader.MoveToContent();
        }

        reader.ReadEndElement();
    }



    public void WriteXml(System.Xml.XmlWriter writer)
    {
        XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
        XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue)); 

        foreach (TKey key in this.Keys)
        {
            writer.WriteStartElement("item");
            writer.WriteStartElement("key");
            keySerializer.Serialize(writer, key);
            writer.WriteEndElement();
            writer.WriteStartElement("value");
            TValue value = this[key];
            valueSerializer.Serialize(writer, value);
            writer.WriteEndElement();
            writer.WriteEndElement();
        }

    }

    #endregion

}

然后使用 SerializableDictionary 对象而不是普通的 Dictionary。同样在我的 CommonControls 类中，我必须使用以下方法实现“IXmlSerializable”。

 #region IXmlSerializable Members

    public System.Xml.Schema.XmlSchema GetSchema()
    {
        throw new NotImplementedException();
    }

    public void ReadXml(XmlReader reader)
    {
        throw new NotImplementedException();
    }

    public void WriteXml(XmlWriter writer)
    {
        throw new NotImplementedException();
    }

    #endregion

现在一切正常。谢谢大家。 ！！！

Answer 3

我想你会发现Dictionary不能用XmlSerializer序列化

Answer 4

我使用来自System.Runtime.Serialization.dll 的DataContractSerializer。使用两个 Dictionary 属性对我的类进行序列化/反序列化，没有任何问题。