What's the easiest way to save an object to a file without serialization attributes?

Question

I have different kinds of objects in c# that I would like to save to a file (XML is preferred) but I can't use serialization since the class are not written by me but are from a DLL.

What is the best solution for this ?

Answer 1

I eventually used JavaScriptSerializer and it does exactly what I was looking for:

List<Person> persons = new List<Person>();
persons.Add(new Person(){Name = "aaa"});
persons.Add(new Person() { Name = "bbb" });

JavaScriptSerializer javaScriptSerializer  = new JavaScriptSerializer();
var strData = javaScriptSerializer.Serialize(persons);

var persons2 = javaScriptSerializer.Deserialize<List<Person>>(strData);

Answer 2

I've whipped up a quick little extension method that will "serialize" to XML, given a non-serializable object. It's pretty rough and doesn't do a heck of a lot of checking and the XML it generates you can easily tweak to meet your needs:

public static string SerializeObject<T>(this T source, bool serializeNonPublic = false)
{
    if (source == null)
    {
        return null;
    }

    var bindingFlags = BindingFlags.Instance | BindingFlags.Public;

    if (serializeNonPublic)
    {
        bindingFlags |= BindingFlags.NonPublic;
    }

    var properties = typeof(T).GetProperties(bindingFlags).Where(property => property.CanRead).ToList();
    var sb = new StringBuilder();

    using (var writer = XmlWriter.Create(sb))
    {
        writer.WriteStartElement(typeof(T).Name);
        if (properties.Any())
        {
            foreach (var property in properties)
            {
                var value = property.GetValue(source, null);

                writer.WriteStartElement(property.Name);
                writer.WriteAttributeString("Type", property.PropertyType.Name);
                writer.WriteAttributeString("Value", value.ToString());
                writer.WriteEndElement();
            }
        }
        else if (typeof(T).IsValueType)
        {
            writer.WriteValue(source.ToString());
        }

        writer.WriteEndElement();
    }

    return sb.ToString();
}

I tested it on this class:

private sealed class Test
{
    private readonly string name;

    private readonly int age;

    public Test(string name, int age)
    {
        this.name = name;
        this.age = age;
    }

    public string Name
    {
        get
        {
            return this.name;
        }
    }

    public int Age
    {
        get
        {
            return this.age;
        }
    }
}

as well as the number 3 and object . The resulting XML is as such:

<?xml version="1.0" encoding="utf-16"?>
<Test>
  <Name Type="String" Value="John Doe" />
  <Age Type="Int32" Value="35" />
</Test>

<?xml version="1.0" encoding="utf-16"?>
<Int32>3</Int32>

<?xml version="1.0" encoding="utf-16"?>
<Object />

respectively.

Answer 3

write your own serializable wrappers around the non-serializable classes of the DLL.

EDIT: AutoMapper was suggested in the comments and I hadn't heard of it yet, but now that I have I'd definitely use that instead of writing the wrappers myself. Unless there's some reflection required to capture some of the internal state of the non-serializable object (if possible), I don't know if AutoMapper has anything to offer there or you'd have to see if you could capture that in your wrapper.

Answer 4

I would write a POCO (Plain Old Class Object) class that mimics the object from the DLL returned. Generally if you are using, I believe, .NET 3.5 or higher you have the ability to use LINQ. I favor Linq to put objects into other classes or perform sorting or other operations on them.

Here is a simple example where you would be dummying in your return object for example. Keep in mind in a DLL of course you could have many differing objects and do this multiple times. I also would wrap my methods up in their own class for re usability instead of doing it in the main. But here is a simple proof of concept

using System;
using System.Linq;
using System.Windows.Forms;
using System.IO;
using System.Xml.Serialization;
using System.Collections.Generic;
using System.Xml.Linq;

namespace ExampleSerializer
{
    class Program
    {
        // example class to serialize
        [Serializable]
        public class SQLBit
        {
            [XmlElement("Name")]
            public string Name { get; set; }

            [XmlText]
            public string data { get; set; }
        }

        // example class to populate to get test data
        public class example
        {
            public string Name { get; set; }
            public string data { get; set; }
        }

        static void Main(string[] args)
        {
            string s = "";

            // make a generic and put some data in it from the test
            var ls = new List<example> { new example { Name = "thing", data = "data" }, new example { Name = "thing2", data = "data2" } };

            // make a second generic and put data from the first one in using a lambda
            // statement creation method.  If your object returned from DLL is a of a
            // type that implements IEnumerable it should be able to be used.
            var otherlist = ls.Select(n => new SQLBit
                {
                    Name = n.Name,
                    data = n.data
                });

            // start a new xml serialization with a type.
            XmlSerializer xmler = new XmlSerializer(typeof(List<SQLBit>));

            // I use a textwriter to start a new instance of a stream writer
            TextWriter twrtr = new StreamWriter(@"C:\Test\Filename.xml");

            // Serialize the stream to the location with the list
            xmler.Serialize(twrtr, otherlist);

            // Close
            twrtr.Close();

            // TODO: You may want to put this in a try catch wrapper and make up your 
            // own classes.  This is a simple example.
         }
    }
}

Answer 5

I think the term "without-serialization" in the question header is misleading.

If i understood you correctly you want to serialize objects that have no serilisation-attributes.

There are libraries like sharpserializer and protobuf-net that can do the job for you.