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
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();
}
}
其他回答
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());
}
}
}
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);
}
}
}
}
序列化和反序列化XML/JSON (SerializationHelper.cs):
using Newtonsoft.Json;
using System.IO;
using System.Xml.Serialization;
namespace MyProject.Helpers
{
public static class SerializationHelper
{
public static T DeserializeXml<T>(this string toDeserialize)
{
XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
using (StringReader textReader = new StringReader(toDeserialize))
{
return (T)xmlSerializer.Deserialize(textReader);
}
}
public static string SerializeXml<T>(this T toSerialize)
{
XmlSerializer xmlSerializer = new XmlSerializer(typeof(T));
using (StringWriter textWriter = new StringWriter())
{
xmlSerializer.Serialize(textWriter, toSerialize);
return textWriter.ToString();
}
}
public static T DeserializeJson<T>(this string toDeserialize)
{
return JsonConvert.DeserializeObject<T>(toDeserialize);
}
public static string SerializeJson<T>(this T toSerialize)
{
return JsonConvert.SerializeObject(toSerialize);
}
}
}
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}
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;
}
