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c#serializationxml-serialization
Roland Deschain
Roland Deschain

Reputation: 2850

Xml Serialization - System.InvalidOperationException: Is it not possible to serialize 'this'?

Hopefully this question isn't too obvious, however I'm taking my first steps into the topic of serialization and couldn't find an explanation for the following behaviour:

I wanted to serialize a class to test if I set up everything correctly. For this I took the code from this tutorial and adapted it as follows:

    private void SerializePresets(string path)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(typeof(MyClass));
        using (TextWriter writer = new StreamWriter(path))
        {
            xmlSerializer.Serialize(writer, this);
        }
    }

This method lies within MyClass and is also called from there. This gives me the following exception:

An exception of type 'System.InvalidOperationException' occurred in System.Xml.dll but was not handled in user code

Additional information: There was an error reflecting type 'MyClass'.

Since MyClass holds other class object as properties first I thought I have to make those serializabel too, however the exception still persists. So, my guess is, that it is impossible serialize this, however I couldn't find a confirmation to this guess.

EDIT: This property causes the issue according to the inner exception:

[XmlArray("VolumePresetList"), XmlArrayItem(typeof(LinearAxisColorPresetsModel), ElementName = "VolumePresetList")]
public ObservableCollection<LinearAxisColorPresetsModel> VolumePresetList { get; set; }

Upvotes: 0

Views: 521

Answers (2)

Roland Deschain
Roland Deschain

Reputation: 2850

With the help of the inner exceptions (thanks for the tip again) I could find out the reason why the serialization failed.

The class LinearAxisColorPresetsModeldid not have a parameterless Constructor, which caused this issue.

Simply adding 

/// <summary>
/// Default Constructor
/// </summary>
private LinearAxisColorPresetsModel()
{

}

to this class solved the problem for me. What remains is to find out the reason, why we must have a parameterless Constructor.

EDIT: Found the reasoning behind this behaviour in this post.

Upvotes: 1

jdweng
jdweng

Reputation: 34421

You can use this. It must be one of the properties like a Dictionary that doesn't serialize. See my example below

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;
using System.IO;

namespace ConsoleApplication103
{
    class Program
    {

        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            MyClass myClass = new MyClass();
            myClass.Serialize(FILENAME);

        }
    }
    public class MyClass
    {
         public string test { get; set; }

         public void Serialize(string filename)
         {
             SerializePresets(filename);
         }
         private void SerializePresets(string path)
         {
             XmlSerializer xmlSerializer = new XmlSerializer(typeof(MyClass));
             using (TextWriter writer = new StreamWriter(path))
             {
                 xmlSerializer.Serialize(writer, this);
             }
        }
    }

}

Upvotes: 1

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