Serialization bugs in .NET?

Question

I'm reading up on serialization, and have so far been messing with BinaryFormatter and SoapFormatter. So far, so good - and everything have both Serialized and Deserialized perfectly.

However, when I try the code below, I would expect my datafile to NOT contains the info for Name - and it does. Why would it contain that, when I specify SoapIgnore on the field?

I also tried with SoapAttribute("SomeAttribute") on the Age-field, and that didn't make any difference either. The framework version is set to 2.0, but the same thing happens in 3.5 and 4.0.

using System;
using System.Runtime.Serialization.Formatters.Soap;
using System.IO;
using System.Xml.Serialization;

class Program
{
    static void Main(string[] args)
    {
        Person p = new Person();
        p.Age = 42;
        p.Name = "Mr Smith";

        SoapFormatter formatter = new SoapFormatter();
        FileStream fs = new FileStream(@"c:\test\data.txt", FileMode.Create);

        formatter.Serialize(fs, p);
    }
}

[Serializable]
class Person
{
    public int Age;
    [SoapIgnore]
    public string Name;
}

H H · Answer 1 · 2010-09-03T11:49:14.317

10

Use [NonSerialized] instead of [SoapIgnore]

Furthermore, this is an older (and aging) API. Not directly wrong but be sure to read up on XmlSerialization and ProtoBuf as well.

And be careful not to mix the API's up. Serialization is part of SOAP communication but not the same. SoapAttribute is not involved in bare Serialization.

edited Sep 03 '10 at 11:49

answered Sep 03 '10 at 11:37

H H

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Nope. Not correct. [NonSerialized] is for the BinaryFormatter. [SoapIgnore] is for the SoapFormatter. [XmlIgnore] is for the XmlSerializer. – Peter Olsen Sep 03 '10 at 11:40
@Peter: Are you sure? From MSDN: When using the BinaryFormatter or SoapFormatter classes to serialize an object, use the NonSerializedAttribute attribute ...., http://msdn.microsoft.com/en-us/library/system.nonserializedattribute.aspx – H H Sep 03 '10 at 11:42
1

@Peter: According to the docs http://msdn.microsoft.com/en-us/library/system.xml.serialization.soapattributes.soapignore.aspx [SoapIgnore] is for the XMLSerializer, not the SoapFormatter – Iain Ward Sep 03 '10 at 11:42
Actually, I'd stay away from the XML Serializer as well, unless you require control over the exact format of the XML. It's in the process of being dropped, along with ASMX web services. – John Saunders Sep 03 '10 at 11:50
So how would I go about serializing an object either through BinaryFormatter, SoapFormatter or XmlSerializer, where I have control over which fields is serialized? The only way seems to be implemented ISerializable - and that might be a TAD overkill. – Peter Olsen Sep 03 '10 at 11:53
OK @John, thanks for the tip. Do you have a link for the ASMX state of affairs? – H H Sep 03 '10 at 11:53
I found a solution - I answered it below. It seems that the SoapFormatter uses NonSerialized just like the BinaryFormatter does. – Peter Olsen Sep 03 '10 at 12:01
And it seems that the MS Press book I'm reading is wrong, in listing SoapIgnore and SoapAttribute alongside SoapFormatters. – Peter Olsen Sep 03 '10 at 12:02
@Henk: no single link, unfortunately. The strongest hint is in Ed Pinto's reply to https://connect.microsoft.com/VisualStudio/feedback/details/362727/xsd-exe-incorrect-class-generated-for-abstract-type-with-derived-types. That and the fact that ASMX web services are replaced by WCF, and XML Serialization has only limited applicability to WCF. – John Saunders Sep 03 '10 at 12:06

score 1 · Answer 2 · answered Sep 03 '10 at 11:36

1

Because serialization and SOAP aren't the same. You have Name marked as public, so the serializer will serialize/deserialize it. If you want it not to appear in a serialization you should change its protection level to protected.

answered Sep 03 '10 at 11:36

Joel Etherton

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This isn't only way to ignore some fields during serialization. – Bart Sep 03 '10 at 11:45
There is a SoapFormatter which is designed to serialized data. I'm not talking about a webservice soap envelope. The MSDN it self states the following about SoapFormatters: "Serializes and deserializes an object, or an entire graph of connected objects, in SOAP format." – Peter Olsen Sep 03 '10 at 11:49
@Bart, @Peter Olsen - I read a little more into your question and some of the responses, and my "answer" isn't complete or accurate. I was tempted to delete it, but that would deprive potential downvoters of a clear and present opportunity. – Joel Etherton Sep 03 '10 at 12:26

score 1 · Answer 3 · answered Sep 03 '10 at 11:40

1

From the docs it states that the [SoapIgnore] attribute tells the XMLSerializer not to serialize this property, and it doesn't mention the SoapFormatter so I assume it doesn't apply to it, even though the name suggests it does

answered Sep 03 '10 at 11:40

Iain Ward

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If I use an XmlSerializer, and use the [SoapIgnore] attribute, it serializes the field. If I change the attribute to [XmlIgnore] it correctly ignores the field. It just makes no sense, that there is no way to tell the serializer, that a given public field shouldn't be serialized. Lets say that I have string firstname, lastname, fullname, and fullname is in the ctor set to firstname +" "+ lastname. Why would I then want to serialize fullname? But I need fullname to be public. – Peter Olsen Sep 03 '10 at 11:45
[NonSerialized] seems to make the SoapFormatter ignore the field. – Peter Olsen Sep 03 '10 at 12:21

score 1 · Answer 4 · answered Sep 03 '10 at 12:00

1

The following code works. It seems that the SoapFormatter uses the same attributes as the BinaryFormatter does - the [NonSerialized] attribute. This however goes against what the MS Press book I'm reading states. It lists SoapIgnore, SoapAttribute and others as attributes that works with the SoapFormatter when serializing data.

This code creates two files, none of them having the Name-field.

using System;
using System.Runtime.Serialization.Formatters.Soap;
using System.IO;
using System.Xml.Serialization;

class Program
{
    static void Main(string[] args)
    {
        Person p = new Person();
        p.Age = 42;
        p.Name = "Mr Smith";

        FormatSoap(p);
        FormatXml(p);
    }

    private static void FormatXml(Person p)
    {
        XmlSerializer serializer = new XmlSerializer(typeof(Person));
        FileStream fs = new FileStream(@"c:\test\xmldata.txt", FileMode.Create);

        serializer.Serialize(fs, p);
    }

    private static void FormatSoap(Person p)
    {
        SoapFormatter formatter = new SoapFormatter();
        FileStream fs = new FileStream(@"c:\test\soapdata.txt", FileMode.Create);

        formatter.Serialize(fs, p);
    }
}

[Serializable]
public class Person
{
    public int Age;
    [XmlIgnore]
    [NonSerialized]
    public string Name;
}

answered Sep 03 '10 at 12:00

Peter Olsen

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Of course this doesn't mean I can alter how I want the resulting soapenvelope to be created - setting some values to soap-attributes and renaming other fields. – Peter Olsen Sep 03 '10 at 12:03
@Peter: which book, and when was it published? – John Saunders Sep 03 '10 at 12:07
1

@John: It's the Self Paced Training Kit for the 70-536 exam (.Net Application Development Foundation). It's even the second edition from 2009. – Peter Olsen Sep 03 '10 at 12:11
@Peter: which version of .NET is the exam for? – John Saunders Sep 03 '10 at 12:20
1

@Peter: BTW, just read the code and have to downvote you for not using `using` blocks around the FileStream's. – John Saunders Sep 03 '10 at 12:21
1

@John hehe, the code isn't productioncode or anything - it was just to make a simple example. The exam is for 2.0. – Peter Olsen Sep 03 '10 at 12:35
The way the code works directly goes against what the MS Press book says? Shocking... – Chris Conway Sep 03 '10 at 12:56
@Peter: non-production, example code is copied by those who don't know what production code looks like, and is actually used. Fix it and I'll remove the -1. – John Saunders Sep 03 '10 at 13:51
@John: should all SO answers be copy-pate ready or focus on the problem as clear as possible? – H H Sep 04 '10 at 09:00
@Henk: I compromise on that by downvoting lack of `using` blocks, missing any locking, and use of `new XmlTextReader()/XmlTextWriter()`These are cases that I've seen used in real code; when asked, the devs have said, "but I got it from an example". – John Saunders Sep 04 '10 at 15:33
@Henk: also, anyone who says, "use WSE". – John Saunders Sep 04 '10 at 15:43
@John, uhhh WSE in this context = ?? – H H Sep 04 '10 at 15:56
@Henk: i was enumerating my reasons for auto downvotes. WSE is a very obsolete web service technology replaced by WCF – John Saunders Sep 04 '10 at 16:43

score 0 · Answer 5 · edited May 23 '17 at 12:19

0

Have a look at this question: Applying SoapIgnore attribute doesn't take any effect to serialization result

edited May 23 '17 at 12:19

Community

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answered Sep 03 '10 at 11:38

Chris Conway

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The answer to that question states, that the SoapIgnore attribute is only for webservices. My question origins from reading the MS Press book for 70-536, where it clearly states that SoapIgnore and SoapAttribute works in union with SoapFormatter for serializing objects. – Peter Olsen Sep 03 '10 at 11:54
Right, but those books are notorious for having mistakes in them. Have you checked the book corrections page to see if it's listed? http://www.microsoft.com/learning/en/us/training/format-books-support.aspx#tab2 – Chris Conway Sep 03 '10 at 12:58

Serialization bugs in .NET?

5 Answers5