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POWhat's up with the [OptionalField] Attribute?
 

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  1. POWhat's up with the [OptionalField] Attribute?
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    <p>As I understand it I have to adorn a new member in a newer version of my class with the [OptionalField] Attribute when I deserialize an older version of my class that lacks this newer member.</p> <p>However, the code below throws no exception while the InnerTranslator property was added after serializing the class. I check for the property to be null in the onDeserialization method (which confirms that it was not serialized),but I would have expected the code to throw an exception because of that. Is the [OptionalField] Attribute itself optional?</p> <pre><code>class Program { static void Main(string[] args) { var listcol = new SortedList&lt;string,string&gt; { {"Estados Unidos", "United States"}, {"Canadá", "Canada"}, {"España", "Spain"} }; var translator = new CountryTranslator(listcol); using (var file_stream=new FileStream("translator.bin",FileMode.Open)) { var formatter = new BinaryFormatter(); translator = formatter.Deserialize(file_stream) as CountryTranslator; file_stream.Close(); } Console.ReadLine(); } } [Serializable] internal class CountryTranslator:IDeserializationCallback { public int Count { get; set; } public CountryTranslator(SortedList&lt;string,string&gt; sorted_list) { this.country_list = sorted_list; inner_translator = new List&lt;string&gt; {"one", "two"}; } //[OptionalField] private List&lt;string&gt; inner_translator; public List&lt;string&gt; InnerTranslator { get { return inner_translator; } set { inner_translator = value; } } private SortedList&lt;string, string&gt; country_list; public void OnDeserialization(object sender) { Debug.Assert(inner_translator == null); Count=country_list.Count; } } </code></pre>
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    1. USDabblernl
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    1. COI just found out that the SOAP formatter does throw an exception when the inner_translator is not adorned with the [OptionalField] Attribute
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      1. USDabblernl
 

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