我有以下方法来保存一个对象到一个文件:

// 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();
}

我承认这不是我写的(我只是把它转换成一个接受类型参数的扩展方法)。

现在我需要它把xml作为字符串返回给我(而不是保存到文件中)。我正在调查这件事,但我还没有弄清楚。

我想对于熟悉这些物体的人来说,这可能很简单。如果没有,我最终会弄清楚的。


当前回答

我知道这不是问题的真正答案,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序列化会给输出增加不必要的额外文本垃圾。

对于下面的类

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

它生成

<?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(最好的方法之一是Json.NET)。 序列化一个对象:

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

反序列化一个对象:

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

序列化的JSON字符串看起来像这样:

{"UserId":0}

其他回答

我觉得我需要分享这个被操纵的代码到公认的答案-因为我没有声誉,我无法评论。

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);
            }
        }
    }
}

我的2 p…

        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());
                }
            }
        }

代码安全说明

关于接受的答案,在XmlSerializer构造函数中使用toSerialize.GetType()而不是typeof(T)是很重要的:如果使用第一种方法,代码将覆盖所有可能的场景,而使用后一种方法有时会失败。

下面是一些示例代码的链接,其中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SerializeObject<T>()的方法,该方法是在派生类型的基类中定义的:http://ideone.com/1Z5J1。注意,Ideone使用Mono来执行代码:使用Microsoft . net运行时获得的实际异常有一个与Ideone上显示的不同的消息,但它同样失败。

为了完整起见,我在这里发布了完整的代码示例,以供将来参考,以防Ideone(我发布代码的地方)将来不可用:

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

public class Test
{
    public static void Main()
    {
        Sub subInstance = new Sub();
        Console.WriteLine(subInstance.TestMethod());
    }

    public class Super
    {
        public string TestMethod() {
            return this.SerializeObject();
        }
    }

    public class Sub : Super
    {
    }
}

public static class TestExt {
    public static string SerializeObject<T>(this T toSerialize)
    {
        Console.WriteLine(typeof(T).Name);             // PRINTS: "Super", the base/superclass -- Expected output is "Sub" instead
        Console.WriteLine(toSerialize.GetType().Name); // PRINTS: "Sub", the derived/subclass

        XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
        StringWriter textWriter = new StringWriter();

        // And now...this will throw and Exception!
        // Changing new XmlSerializer(typeof(T)) to new XmlSerializer(subInstance.GetType()); 
        // solves the problem
        xmlSerializer.Serialize(textWriter, toSerialize);
        return textWriter.ToString();
    }
}

我无法使用xhafan建议的JSONConvert方法

在。net 4.5中,即使添加了“System.Web.”扩展程序集引用我仍然无法访问JSONConvert。

然而,一旦你添加了引用,你可以使用以下方法打印出相同的字符串:

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

在极少数情况下,您可能希望实现自己的String序列化。

但这可能是个坏主意,除非你知道自己在做什么。(例如用批处理文件序列化I/O)

类似这样的方法就可以达到目的(而且手动/批处理编辑也很容易),但是要注意应该做更多的检查,比如名称不包含换行符。

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;
}