C#无法将我的字典序列化为XML

时间:2017-01-04 19:05:23

标签: c# xml dictionary serialization

我正在开发一个小项目来学习如何在C#.NET中序列化对象我创建了以下类,这是我尝试序列化的类:

public class Object
{
    private Dictionary<string, int> dictionaryStringInt;

    public Object()
    {
        this.dictionaryStringInt = new Dictionary<string, int>();
    }

    public void AddToDictionary(string s, int i)
    {
        this.dictionaryStringInt.Add(s, i);
    }

    public List<DictionaryEntry> DictionaryStringInt
    {
        get
        {
            List<DictionaryEntry> list = new List<DictionaryEntry>();
            foreach (KeyValuePair<string, int> element in dictionaryStringInt)
            {
                list.Add(new DictionaryEntry(element.Key, element.Value));
            }
            return list;
        }

        set
        {
            Dictionary<string, int> dictionary = new Dictionary<string, int>();
            foreach (DictionaryEntry entry in value)
            {
                dictionary.Add(entry.Key, entry.Value);
            }

            dictionaryStringInt = dictionary;
        }
    }

    public class DictionaryEntry
    {
        private string key;
        private int value;

        public DictionaryEntry()
        {
            this.key = string.Empty;
            this.value = 0;
        }

        public DictionaryEntry(string key, int value)
        {
            this.key = key;
            this.value = value;
        }

        [XmlAttribute("Key")]
        public string Key
        {
            get
            {
                return key;
            }

            set
            {
                key = value;
            }
        }

        [XmlText]
        public int Value
        {
            get
            {
                return value;
            }

            set
            {
                this.value = value;
            }
        }
    }
}

我在这里有这个代码可以完成工作:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        this.ClearTextBox();
        SerialisationTest.Object @object = this.SetUpObject();
        this.Serialize(@object);
        @object = null;
        @object = this.Deserialise(@"C:\Sources\SerialisationTest\test.xml");
        this.textBox1.Text = @object.ToString();
        this.DisplayXML(@object);
    }

    public void Serialize(SerialisationTest.Object @object)
    {
        XmlSerializer serializer = new XmlSerializer(typeof(SerialisationTest.Object));
        using (TextWriter writer = new StreamWriter(@"C:\Sources\SerialisationTest\test.xml"))
        {
            serializer.Serialize(writer, @object);
        }
    }

    public SerialisationTest.Object Deserialise(string path)
    {
        XmlSerializer serializer = new XmlSerializer(typeof(SerialisationTest.Object));
        using (TextReader reader = new StreamReader(path))
        {
            return (SerialisationTest.Object)serializer.Deserialize(reader);
        }
    }

    public void DisplayXML(SerialisationTest.Object @object)
    {
        XmlSerializer serializer = new XmlSerializer(typeof(SerialisationTest.Object));
        using (StringWriter writer = new StringWriter())
        {
            serializer.Serialize(writer, @object);
            this.textBox1.Text = writer.ToString();
        }
    }

    public SerialisationTest.Object SetUpObject()
    {
        SerialisationTest.Object @object = new SerialisationTest.Object();

        @object.AddToDictionary("1", 1);
        @object.AddToDictionary("2", 2);
        @object.AddToDictionary("3", 3);

        return @object;
    }

    public void ClearTextBox()
    {
        this.textBox1.Text = "";
    }
}

现在这是我在文本框中看到的结果:

<?xml version="1.0" encoding="utf-16"?>
<Object xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <DictionaryStringInt />
</Object>

现在大多数代码都是我在试图序列化事物。但后来我尝试序列化DictionaryStringInt并在MSDN上看到Dictionary无法序列化。因此,我尝试通过让属性返回DictionaryEntry列表并将此列表转换为setter中的字典来欺骗序列化程序。但正如您所看到的,DictionaryStringInt的数据未被序列化。我希望得到类似的东西:

<?xml version="1.0" encoding="utf-16"?>
<Object xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
    <DictionaryStringInt>
        <DictionaryEntry Key="1">1</DictionaryEntry>
        <DictionaryEntry Key="2">2</DictionaryEntry>
        <DictionaryEntry Key="3">3</DictionaryEntry>
    </DictionaryStringInt>
</Object> 

有谁知道如何实现这一目标? (顺便说一句,我知道如果在反序列化字典时我在XML中有多个相同的键,我会得到某种类型的KeyAlreadyPresentException,这是一种行为需要)

谢谢!

修改

我刚发现"C:\Sources\SerialisationTest\test.xml"包含正确的结果。

因此,反序列化或使用StringWriter显示序列化似乎存在问题。

我做错了吗?

EDIT2

简化代码

EDIT3

我查看了评论中链接的答案,我认为我得到了正在发生的事情......在其中一个答案中有一条评论指出,不会调用setter,而是应该使用数组。我正在研究这个问题。

1 个答案:

答案 0 :(得分:2)

问题是您在反序列化期间丢失了代理List<DictionaryEntry> DictionaryStringInt属性的内容。解决方法是将其更改为数组:

        DictionaryEntry [] DictionaryStringInt
        {
            get
            {
                if (dictionaryStringInt == null)
                    return null;
                List<DictionaryEntry> list = new List<DictionaryEntry>();
                foreach (KeyValuePair<string, int> element in dictionaryStringInt)
                {
                    list.Add(new DictionaryEntry(element.Key, element.Value));
                }
                return list.ToArray();
            }

            set
            {
                if (value == null)
                    return;
                Dictionary<string, int> dictionary = new Dictionary<string, int>();
                foreach (DictionaryEntry entry in value)
                {
                    dictionary.Add(entry.Key, entry.Value);
                }

                dictionaryStringInt = dictionary;
            }
        }

有关反序列化期间List<DictionaryEntry>代理属性失败的原因的解释,请参阅Cannot deserialize XML into a list using XML Deserializer。正如那里所解释的那样:

  1. XmlSerializer调用getter获取列表。如果为null,则分配一个列表并通过setter设置它。它在阅读时保留在一些局部变量的列表中。

  2. 它反序列化每个列表元素,并将其添加到它所持有的列表中。

  3. 就是这样。之后它永远不会调用包含类的 list属性setter 。因此,列表的内容永远不会填充到您的字典中。

  4. 但是,由于数组在分配后无法调整大小,因此必须在读取和反序列化其内容后对其进行分配和设置。因此,在反序列化期间,数组属性可以作为代理。