将对象序列化为字符串

时间:2010-03-12 17:24:39

标签: c# string serialization xml-serialization

我有以下方法将Object保存到文件中:

// Save an object out to the disk
public static void SerializeObject<T>(this T toSerialize, String filename)
{
    XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());
    TextWriter textWriter = new StreamWriter(filename);

    xmlSerializer.Serialize(textWriter, toSerialize);
    textWriter.Close();
}

我承认我没有写它(我只将其转换为带有类型参数的扩展方法)。

现在我需要它将xml作为字符串返回给我(而不是将其保存到文件中)。我正在研究它,但我还没想到它。

我认为对于熟悉这些对象的人来说这可能很容易。如果不是,我最终会弄明白。

10 个答案:

答案 0 :(得分:481)

使用StringWriter代替StreamWriter

public static string SerializeObject<T>(this T toSerialize)
{
    XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());

    using(StringWriter textWriter = new StringWriter())
    {
        xmlSerializer.Serialize(textWriter, toSerialize);
        return textWriter.ToString();
    }
}

注意,在XmlSerializer构造函数中使用toSerialize.GetType()而不是typeof(T)非常重要:如果使用第一个,则代码涵盖T的所有可能子类(对于T有效方法),当使用后者时,在传递从XmlSerializer派生的类型时会失败。 下面是一个链接,其中包含一些激励此语句的示例代码,Exception在使用typeof(T)时抛出Exception,因为您将派生类型的实例传递给调用SerializeObject的方法在派生类型的基类中定义:http://ideone.com/1Z5J1

此外,Ideone使用Mono执行代码;使用Microsoft .NET运行时获得的实际Message与Ideone上显示的{{1}}具有不同的{{1}},但它会失败。

答案 1 :(得分:67)

我知道这不是问题的答案,但根据问题的投票数和接受的答案,我怀疑人们实际上是在使用代码将对象序列化为字符串。

使用XML序列化会在输出中添加不必要的额外文本垃圾。

以下课程

public class UserData
{
    public int UserId { get; set; }
}

它会生成

<?xml version="1.0" encoding="utf-16"?>
<UserData xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <UserId>0</UserId>
</UserData>

更好的解决方案是使用JSON序列化(其中最好的是Json.NET)。 序列化对象:

var userData = new UserData {UserId = 0};
var userDataString = JsonConvert.SerializeObject(userData);

反序列化对象:

var userData = JsonConvert.DeserializeObject<UserData>(userDataString);

序列化的JSON字符串如下所示:

{"UserId":0}

答案 2 :(得分:52)

序列化和反序列化:

    public static T Deserialize<T>(this string toDeserialize)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
        using(StringReader textReader = new StringReader(toDeserialize))
        {      
            return (T)xmlSerializer.Deserialize(textReader);
        }
    }

    public static string Serialize<T>(this T toSerialize)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
        using(StringWriter textWriter = new StringWriter())
        {
            xmlSerializer.Serialize(textWriter, toSerialize);
            return textWriter.ToString();
        }
    }

答案 3 :(得分:37)

代码安全说明

关于accepted answer,在toSerialize.GetType()构造函数中使用typeof(T)代替XmlSerializer非常重要:如果您使用第一个代码,则代码涵盖所有可能的方案,而使用后者有时会失败。

这是一个链接,其中包含一些激励此语句的示例代码,XmlSerializer在使用typeof(T)时抛出异常,因为您将派生类型的实例传递给调用{{ 1}}在派生类型的基类中定义:http://ideone.com/1Z5J1请注意,Ideone使用Mono执行代码:使用Microsoft .NET运行时获得的实际异常消息与Ideone上显示的消息不同,但它的失败方式相同。

为了完整起见,我在此处发布完整的代码示例以供将来参考,以防万一 Ideone (我发布的代码)在将来变得不可用:

SerializeObject<T>()

答案 4 :(得分:10)

我的2p ......

        string Serialise<T>(T serialisableObject)
        {
            var xmlSerializer = new XmlSerializer(serialisableObject.GetType());

            using (var ms = new MemoryStream())
            {
                using (var xw = XmlWriter.Create(ms, 
                    new XmlWriterSettings()
                        {
                            Encoding = new UTF8Encoding(false),
                            Indent = true,
                            NewLineOnAttributes = true,
                        }))
                {
                    xmlSerializer.Serialize(xw,serialisableObject);
                    return Encoding.UTF8.GetString(ms.ToArray());
                }
            }
        }

答案 5 :(得分:4)

public static string SerializeObject<T>(T objectToSerialize)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            MemoryStream memStr = new MemoryStream();

            try
            {
                bf.Serialize(memStr, objectToSerialize);
                memStr.Position = 0;

                return Convert.ToBase64String(memStr.ToArray());
            }
            finally
            {
                memStr.Close();
            }
        }

        public static T DerializeObject<T>(string objectToDerialize)
        {
            System.Runtime.Serialization.Formatters.Binary.BinaryFormatter bf = new System.Runtime.Serialization.Formatters.Binary.BinaryFormatter();
            byte[] byteArray = Convert.FromBase64String(objectToDerialize);
            MemoryStream memStr = new MemoryStream(byteArray);

            try
            {
                return (T)bf.Deserialize(memStr);
            }
            finally
            {
                memStr.Close();
            }
        }

答案 6 :(得分:1)

我无法使用xhafan建议的JSONConvert方法

在.Net 4.5中,即使添加了&#34; System.Web.Extensions&#34;程序集引用我仍然无法访问JSONConvert。

但是,添加引用后,您可以使用以下命令打印出相同的字符串:

JavaScriptSerializer js = new JavaScriptSerializer();
string jsonstring = js.Serialize(yourClassObject);

答案 7 :(得分:0)

我觉得我需要将这个可操纵的代码分享给公认的答案-因为我没有声誉,所以无法发表评论。

using System;
using System.Xml.Serialization;
using System.IO;

namespace ObjectSerialization
{
    public static class ObjectSerialization
    {
        // THIS: (C): https://stackoverflow.com/questions/2434534/serialize-an-object-to-string
        /// <summary>
        /// A helper to serialize an object to a string containing XML data of the object.
        /// </summary>
        /// <typeparam name="T">An object to serialize to a XML data string.</typeparam>
        /// <param name="toSerialize">A helper method for any type of object to be serialized to a XML data string.</param>
        /// <returns>A string containing XML data of the object.</returns>
        public static string SerializeObject<T>(this T toSerialize)
        {
            // create an instance of a XmlSerializer class with the typeof(T)..
            XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());

            // using is necessary with classes which implement the IDisposable interface..
            using (StringWriter stringWriter = new StringWriter())
            {
                // serialize a class to a StringWriter class instance..
                xmlSerializer.Serialize(stringWriter, toSerialize); // a base class of the StringWriter instance is TextWriter..
                return stringWriter.ToString(); // return the value..
            }
        }

        // THIS: (C): VPKSoft, 2018, https://www.vpksoft.net
        /// <summary>
        /// Deserializes an object which is saved to an XML data string. If the object has no instance a new object will be constructed if possible.
        /// <note type="note">An exception will occur if a null reference is called an no valid constructor of the class is available.</note>
        /// </summary>
        /// <typeparam name="T">An object to deserialize from a XML data string.</typeparam>
        /// <param name="toDeserialize">An object of which XML data to deserialize. If the object is null a a default constructor is called.</param>
        /// <param name="xmlData">A string containing a serialized XML data do deserialize.</param>
        /// <returns>An object which is deserialized from the XML data string.</returns>
        public static T DeserializeObject<T>(this T toDeserialize, string xmlData)
        {
            // if a null instance of an object called this try to create a "default" instance for it with typeof(T),
            // this will throw an exception no useful constructor is found..
            object voidInstance = toDeserialize == null ? Activator.CreateInstance(typeof(T)) : toDeserialize;

            // create an instance of a XmlSerializer class with the typeof(T)..
            XmlSerializer xmlSerializer = new XmlSerializer(voidInstance.GetType());

            // construct a StringReader class instance of the given xmlData parameter to be deserialized by the XmlSerializer class instance..
            using (StringReader stringReader = new StringReader(xmlData))
            {
                // return the "new" object deserialized via the XmlSerializer class instance..
                return (T)xmlSerializer.Deserialize(stringReader);
            }
        }

        // THIS: (C): VPKSoft, 2018, https://www.vpksoft.net
        /// <summary>
        /// Deserializes an object which is saved to an XML data string.
        /// </summary>
        /// <param name="toDeserialize">A type of an object of which XML data to deserialize.</param>
        /// <param name="xmlData">A string containing a serialized XML data do deserialize.</param>
        /// <returns>An object which is deserialized from the XML data string.</returns>
        public static object DeserializeObject(Type toDeserialize, string xmlData)
        {
            // create an instance of a XmlSerializer class with the given type toDeserialize..
            XmlSerializer xmlSerializer = new XmlSerializer(toDeserialize);

            // construct a StringReader class instance of the given xmlData parameter to be deserialized by the XmlSerializer class instance..
            using (StringReader stringReader = new StringReader(xmlData))
            {
                // return the "new" object deserialized via the XmlSerializer class instance..
                return xmlSerializer.Deserialize(stringReader);
            }
        }
    }
}

答案 8 :(得分:-1)

在极少数情况下,您可能希望实现自己的String序列化。

但这可能是一个糟糕的想法,除非你知道自己在做什么。 (例如,使用批处理文件对I / O进行序列化)

这样的东西可以解决问题(手动/批量编辑很容易),但要注意应该做更多的检查,比如这个名字不包含换行符。

public string name {get;set;}
public int age {get;set;}

Person(string serializedPerson) 
{
    string[] tmpArray = serializedPerson.Split('\n');
    if(tmpArray.Length>2 && tmpArray[0].Equals("#")){
        this.name=tmpArray[1];
        this.age=int.TryParse(tmpArray[2]);
    }else{
        throw new ArgumentException("Not a valid serialization of a person");
    }
}

public string SerializeToString()
{
    return "#\n" +
           name + "\n" + 
           age;
}

答案 9 :(得分:-1)

[VB]

Public Function XmlSerializeObject(ByVal obj As Object) As String

    Dim xmlStr As String = String.Empty

    Dim settings As New XmlWriterSettings()
    settings.Indent = False
    settings.OmitXmlDeclaration = True
    settings.NewLineChars = String.Empty
    settings.NewLineHandling = NewLineHandling.None

    Using stringWriter As New StringWriter()
        Using xmlWriter__1 As XmlWriter = XmlWriter.Create(stringWriter, settings)

            Dim serializer As New XmlSerializer(obj.[GetType]())
            serializer.Serialize(xmlWriter__1, obj)

            xmlStr = stringWriter.ToString()
            xmlWriter__1.Close()
        End Using

        stringWriter.Close()
    End Using

    Return xmlStr.ToString
End Function

Public Function XmlDeserializeObject(ByVal data As [String], ByVal objType As Type) As Object

    Dim xmlSer As New System.Xml.Serialization.XmlSerializer(objType)
    Dim reader As TextReader = New StringReader(data)

    Dim obj As New Object
    obj = DirectCast(xmlSer.Deserialize(reader), Object)
    Return obj
End Function

[C#]

public string XmlSerializeObject(object obj)
{
    string xmlStr = String.Empty;
    XmlWriterSettings settings = new XmlWriterSettings();
    settings.Indent = false;
    settings.OmitXmlDeclaration = true;
    settings.NewLineChars = String.Empty;
    settings.NewLineHandling = NewLineHandling.None;

    using (StringWriter stringWriter = new StringWriter())
    {
        using (XmlWriter xmlWriter = XmlWriter.Create(stringWriter, settings))
        {
            XmlSerializer serializer = new XmlSerializer( obj.GetType());
            serializer.Serialize(xmlWriter, obj);
            xmlStr = stringWriter.ToString();
            xmlWriter.Close();
        }
    }
    return xmlStr.ToString(); 
}

public object XmlDeserializeObject(string data, Type objType)
{
    XmlSerializer xmlSer = new XmlSerializer(objType);
    StringReader reader = new StringReader(data);

    object obj = new object();
    obj = (object)(xmlSer.Deserialize(reader));
    return obj;
}