自定義一個可以被序列化的泛型Dictionary<TKey,TValue>集合，tkeytvalue

自定義一個可以被序列化的泛型Dictionary<TKey,TValue>集合，tkeytvalue

Dictionary是一個鍵值類型的集合。它有點像數組，但Dictionary的鍵可以是任何類型，內部使用Hash Table存儲鍵和值。本篇自定義一個類型安全的泛型Dictionary<TKey, TValue>,並且可以被序列化。

為了使自定義的泛型Dictionary<TKey, TValue>可以被序列化成xml，需要實現泛型IXmlSerializable接口。

    public class MySerializableDictionary<TKey, TValue> : Dictionary<TKey, TValue>, IXmlSerializable
    {
        public System.Xml.Schema.XmlSchema GetSchema()
        {
            return null;
        }
        public void ReadXml(System.Xml.XmlReader reader)
        {
            //鍵的xml序列化器
            XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
            //值的xml序列化器
            XmlSerializer valueSerializer = new XmlSerializer(typeof(TValue));
            //判斷xml中當前節點是否為null
            bool wasEmpty = reader.IsEmptyElement;
            reader.Read();
            if (wasEmpty)
            {
                return;
            }
            while (reader.NodeType != System.Xml.XmlNodeType.EndElement)
            {
               //先讀鍵
                reader.ReadStartElement("item");
                reader.ReadStartElement("key");
                //反序列化成鍵的類型
                TKey key = (TKey) keySerializer.Deserialize(reader);
                reader.ReadEndElement();
                //再讀值
                reader.ReadStartElement("value");
                TValue value = (TValue)valueSerializer.Deserialize(reader);
                reader.ReadEndElement();
                this.Add(key, value);
                reader.ReadEndElement();
                //讀下一個節點
                reader.MoveToContent();
            }
            reader.ReadEndElement();
        }
        public void WriteXml(System.Xml.XmlWriter writer)
        {
            //鍵的xml序列化器
            XmlSerializer keySerializer = new XmlSerializer(typeof(TKey));
            //值的xml序列化器
            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();
            }
        }
    }

客戶端使用XmlWriter把Dictionary<TKey, TValue>這個泛型集合寫進xml中。

    class Program
    {
        static void Main(string[] args)
        {
            MySerializableDictionary<int, string> mySerializableDictionary = new MySerializableDictionary<int, string>();
            mySerializableDictionary.Add(1,"darren");
            mySerializableDictionary.Add(2, "jack");
            using (XmlWriter writer = XmlWriter.Create("infos.xml"))
            {
                writer.WriteStartDocument();
                writer.WriteStartElement("infos");
                foreach (var item in mySerializableDictionary)
                {
                    mySerializableDictionary.WriteXml(writer);
                }
                writer.WriteEndElement();
                writer.WriteEndDocument();
            }
            Console.WriteLine("寫入xml成功");
            Console.ReadKey();
        }
    }   

在Debug文件夾中可找到生成的infos.xml文件。