Serialize包含Dictionary成员的Class

时间：2009-01-30 14:23:46

标签： c# .net serialization dictionary

扩展我的earlier problem，我决定（de）序列化我的配置文件类，该类运行良好。

我现在想要存储一个驱动字母的关联数组来映射（键是驱动器号，值是网络路径）并尝试使用Dictionary，HybridDictionary和{{1}为此，但在调用Hashtable或ConfigFile.Load()时，我总是会收到以下错误：

  

有反映类型的错误   'App.ConfigFile'。 [剪断]   System.NotSupportedException：不能   序列化成员   App.Configfile.mappedDrives [snip]

从我读过的词典和HashTables可以被序列化，所以我做错了什么？

ConfigFile.Save()

10 个答案:

答案 0 :(得分：170)

Paul Welter's Weblog - XML Serializable Generic Dictionary

有一个解决方案
  

由于某种原因，.net 2.0中的通用词典不是XML可序列化的。以下代码段是xml可序列化的通用字典。通过实现IXmlSerializable接口，字典是可序列化的。 

using System;
using System.Collections.Generic;
using System.Text;
using System.Xml.Serialization;

[XmlRoot("dictionary")]
public class SerializableDictionary<TKey, TValue>
    : Dictionary<TKey, TValue>, IXmlSerializable
{
    public SerializableDictionary() { }
    public SerializableDictionary(IDictionary<TKey, TValue> dictionary) : base(dictionary) { }
    public SerializableDictionary(IDictionary<TKey, TValue> dictionary, IEqualityComparer<TKey> comparer) : base(dictionary, comparer) { }
    public SerializableDictionary(IEqualityComparer<TKey> comparer) : base(comparer) { }
    public SerializableDictionary(int capacity) : base(capacity) { }
    public SerializableDictionary(int capacity, IEqualityComparer<TKey> comparer) : base(capacity, comparer) { }

    #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
}

答案 1 :(得分：70)

您无法序列化实现IDictionary的类。看看这个link。

  

问：为什么我不能序列化哈希表？

     

答：XmlSerializer无法处理   实现IDictionary的类   接口。这部分是由于   安排约束和部分原因   事实上哈希表没有   有一个XSD类型的对应物   系统。唯一的解决方案是   实现一个自定义哈希表   没有实现IDictionary   接口

所以我认为你需要为此创建自己的字典版本。请检查此other question。

答案 2 :(得分：53)

您可以使用XmlSerializer而不是System.Runtime.Serialization.DataContractSerializer。这可以使字典和界面序列化，不会出汗。

以下是完整示例http://theburningmonk.com/2010/05/net-tips-xml-serialize-or-deserialize-dictionary-in-csharp/

的链接

答案 3 :(得分：12)

创建序列化代理。

示例，您有一个具有Dictionary类型的公共属性的类。

要支持此类型的Xml序列化，请创建一个通用键值类：

public class SerializeableKeyValue<T1,T2>
{
    public T1 Key { get; set; }
    public T2 Value { get; set; }
}

将XmlIgnore属性添加到原始属性：

    [XmlIgnore]
    public Dictionary<int, string> SearchCategories { get; set; }

公开数组类型的公共属性，它包含一个SerializableKeyValue实例数组，用于序列化和反序列化为SearchCategories属性：

    public SerializeableKeyValue<int, string>[] SearchCategoriesSerializable
    {
        get
        {
            var list = new List<SerializeableKeyValue<int, string>>();
            if (SearchCategories != null)
            {
                list.AddRange(SearchCategories.Keys.Select(key => new SerializeableKeyValue<int, string>() {Key = key, Value = SearchCategories[key]}));
            }
            return list.ToArray();
        }
        set
        {
            SearchCategories = new Dictionary<int, string>();
            foreach (var item in value)
            {
                SearchCategories.Add( item.Key, item.Value );
            }
        }
    }

答案 4 :(得分：9)

你应该探索Json.Net，非常容易使用，并允许直接在Dictionary中反序列化Json对象。

james_newtonking

示例：

string json = @"{""key1"":""value1"",""key2"":""value2""}";
Dictionary<string, string> values = JsonConvert.DeserializeObject<Dictionary<string, string>>(json); 
Console.WriteLine(values.Count);
// 2
Console.WriteLine(values["key1"]);
// value1

答案 5 :(得分：6)

字典和哈希表不能与XmlSerializer序列化。因此，您无法直接使用它们。解决方法是使用XmlIgnore属性隐藏序列化程序中的这些属性，并通过可序列化的键值对列表公开它们。

PS：构建XmlSerializer非常昂贵，所以如果有可能重新使用它，请始终将其缓存。

答案 6 :(得分：4)

我想要一个使用xml属性作为键/值的SerializableDictionary类，所以我已经改编了Paul Welter的课程。

这会生成xml，如：

<Dictionary>
  <Item Key="Grass" Value="Green" />
  <Item Key="Snow" Value="White" />
  <Item Key="Sky" Value="Blue" />
</Dictionary>"

代码：

using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;

namespace DataTypes {
    [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(XmlReader reader) {
            XDocument doc = null;
            using (XmlReader subtreeReader = reader.ReadSubtree()) {
                doc = XDocument.Load(subtreeReader);
            }
            XmlSerializer serializer = new XmlSerializer(typeof(SerializableKeyValuePair<TKey, TValue>));
            foreach (XElement item in doc.Descendants(XName.Get("Item"))) {
                using(XmlReader itemReader =  item.CreateReader()) {
                    var kvp = serializer.Deserialize(itemReader) as SerializableKeyValuePair<TKey, TValue>;
                    this.Add(kvp.Key, kvp.Value);
                }
            }
            reader.ReadEndElement();
        }

        public void WriteXml(System.Xml.XmlWriter writer) {
            XmlSerializer serializer = new XmlSerializer(typeof(SerializableKeyValuePair<TKey, TValue>));
            XmlSerializerNamespaces ns = new XmlSerializerNamespaces();
            ns.Add("", "");
            foreach (TKey key in this.Keys) {
                TValue value = this[key];
                var kvp = new SerializableKeyValuePair<TKey, TValue>(key, value);
                serializer.Serialize(writer, kvp, ns);
            }
        }
        #endregion

        [XmlRoot("Item")]
        public class SerializableKeyValuePair<TKey, TValue> {
            [XmlAttribute("Key")]
            public TKey Key;

            [XmlAttribute("Value")]
            public TValue Value;

            /// <summary>
            /// Default constructor
            /// </summary>
            public SerializableKeyValuePair() { }
        public SerializableKeyValuePair (TKey key, TValue value) {
            Key = key;
            Value = value;
        }
    }
}
}

单元测试：

using System.IO;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace DataTypes {
    [TestClass]
    public class SerializableDictionaryTests {
        [TestMethod]
        public void TestStringStringDict() {
            var dict = new SerializableDictionary<string, string>();
            dict.Add("Grass", "Green");
            dict.Add("Snow", "White");
            dict.Add("Sky", "Blue");
            dict.Add("Tomato", "Red");
            dict.Add("Coal", "Black");
            dict.Add("Mud", "Brown");

            var serializer = new System.Xml.Serialization.XmlSerializer(dict.GetType());
            using (var stream = new MemoryStream()) {
                // Load memory stream with this objects xml representation
                XmlWriter xmlWriter = null;
                try {
                    xmlWriter = XmlWriter.Create(stream);
                    serializer.Serialize(xmlWriter, dict);
                } finally {
                    xmlWriter.Close();
                }

                // Rewind
                stream.Seek(0, SeekOrigin.Begin);

                XDocument doc = XDocument.Load(stream);
                Assert.AreEqual("Dictionary", doc.Root.Name);
                Assert.AreEqual(dict.Count, doc.Root.Descendants().Count());

                // Rewind
                stream.Seek(0, SeekOrigin.Begin);
                var outDict = serializer.Deserialize(stream) as SerializableDictionary<string, string>;
                Assert.AreEqual(dict["Grass"], outDict["Grass"]);
                Assert.AreEqual(dict["Snow"], outDict["Snow"]);
                Assert.AreEqual(dict["Sky"], outDict["Sky"]);
            }
        }

        [TestMethod]
        public void TestIntIntDict() {
            var dict = new SerializableDictionary<int, int>();
            dict.Add(4, 7);
            dict.Add(5, 9);
            dict.Add(7, 8);

            var serializer = new System.Xml.Serialization.XmlSerializer(dict.GetType());
            using (var stream = new MemoryStream()) {
                // Load memory stream with this objects xml representation
                XmlWriter xmlWriter = null;
                try {
                    xmlWriter = XmlWriter.Create(stream);
                    serializer.Serialize(xmlWriter, dict);
                } finally {
                    xmlWriter.Close();
                }

                // Rewind
                stream.Seek(0, SeekOrigin.Begin);

                XDocument doc = XDocument.Load(stream);
                Assert.AreEqual("Dictionary", doc.Root.Name);
                Assert.AreEqual(3, doc.Root.Descendants().Count());

                // Rewind
                stream.Seek(0, SeekOrigin.Begin);
                var outDict = serializer.Deserialize(stream) as SerializableDictionary<int, int>;
                Assert.AreEqual(dict[4], outDict[4]);
                Assert.AreEqual(dict[5], outDict[5]);
                Assert.AreEqual(dict[7], outDict[7]);
            }
        }
    }
}

答案 7 :(得分：2)

Dictionary类实现了ISerializable。下面给出的类字典的定义。

[DebuggerTypeProxy(typeof(Mscorlib_DictionaryDebugView<,>))]
[DebuggerDisplay("Count = {Count}")]
[Serializable]
[System.Runtime.InteropServices.ComVisible(false)]
public class Dictionary<TKey,TValue>: IDictionary<TKey,TValue>, IDictionary, IReadOnlyDictionary<TKey, TValue>, ISerializable, IDeserializationCallback

我不认为这是问题所在。请参阅下面的链接，该链接表示如果您有任何其他不可序列化的数据类型，那么Dictionary将不会被序列化。 http://forums.asp.net/t/1734187.aspx?Is+Dictionary+serializable+

答案 8 :(得分：2)

您可以使用ExtendedXmlSerializer。 如果你有一个班级：

public class ConfigFile
{
    public String guiPath { get; set; }
    public string configPath { get; set; }
    public Dictionary<string, string> mappedDrives {get;set;} 

    public ConfigFile()
    {
        mappedDrives = new Dictionary<string, string>();
    }
}

并创建此类的实例：

ConfigFile config = new ConfigFile();
config.guiPath = "guiPath";
config.configPath = "configPath";
config.mappedDrives.Add("Mouse", "Logitech MX Master");
config.mappedDrives.Add("keyboard", "Microsoft Natural Ergonomic Keyboard 4000");

您可以使用ExtendedXmlSerializer序列化此对象：

ExtendedXmlSerializer serializer = new ExtendedXmlSerializer();
var xml = serializer.Serialize(config);

输出xml如下所示：

<?xml version="1.0" encoding="utf-8"?>
<ConfigFile type="Program+ConfigFile">
    <guiPath>guiPath</guiPath>
    <configPath>configPath</configPath>
    <mappedDrives>
        <Item>
            <Key>Mouse</Key>
            <Value>Logitech MX Master</Value>
        </Item>
        <Item>
            <Key>keyboard</Key>
            <Value>Microsoft Natural Ergonomic Keyboard 4000</Value>
        </Item>
    </mappedDrives>
</ConfigFile>

您可以从nuget安装ExtendedXmlSerializer或运行以下命令：

Install-Package ExtendedXmlSerializer

这是online example

答案 9 :(得分：0)

本文将详细说明如何处理此问题： How do I... Serialize a hash table in C# when the application requires it?

我希望这很有用

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