Exception Field not found: 'System.Runtime.Serialization.XmlObjectSerializerContext.serializerKnownDataContracts'.

Question

Hi All, 

    I am calling a business layer method call as below: 

List<UsageCategorySummary> prodUsageCategorySummary = ProductDomain.Instance.GetUsageCategories();

hidUsageCategory.Value = this.JsonSerializerHelper(prodUsageCategorySummary);


Helper function code 

private string JsonSerializerHelper(System.Object objRef)

{

string result = string.Empty;

using (MemoryStream memoryStream = new MemoryStream())

{

DataContractJsonSerializer serializer = new DataContractJsonSerializer(objRef.GetType());

// Resulting to an exception...

// //  Exception Field not found: 'System.Runtime.Serialization.XmlObjectSerializerContext.serializerKnownDataContracts'.
serializer.WriteObject(memoryStream, objRef);
memoryStream.Position = 0;

using (StreamReader streamReader = new StreamReader(memoryStream))

{

result = streamReader.ReadToEnd();

}

}

return result;

}

Exception occurring at the above colored line... any thoughts?!

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HydPhani

Answer 1

Sorry, but what exactly is the execption (namespace.type) and what is the exact exception message?

/Calle

Answer 2

 Seems like your object cannot be serialized. This can happen if you have a child List collection.
See http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=302308&SiteID=1

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Please remember to mark as answered. -- With Regards Shailen Sukul (Shane) Software Architect/Developer/Consultant/Trainer (BSc | Mct | Mcpd | Mcts (Sharepoint (IP), Biztalk, Web, Win, Dist Apps) | Mcsd.NET | Mcsd | Mcad) Ashlen Consulting Services Pty Ltd (http://www.ashlen.com.au) MSN | Skype | GTalk Id: shailensukul Ph: [phone] Fax: [phone] Blog: http://shailensukul.blogspot.com