Xamarin: System.Nullreferenceexception when try to deserialize object

Question

I try to deserialize object and get System.NullReferenceException. I can't find where exception is fired and what is the cause of exception.

I try to deserialize like this:

public static List<T> Get<T>()
{
    string path = GetFilePath (typeof(T));
    List<T> list;
    using (StreamReader stream = new StreamReader (path)) 
    {
        XmlSerializer serializer = new XmlSerializer (typeof(List<T>));                     
        list = (List<T>)serializer.Deserialize (stream);                        
    }
    return list;
}

StackTrace

at System.Xml.Serialization.XmlSerializationReader.OnUnknownNode (System.Xml.XmlNode node, System.Object o, System.String qnames) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReader.UnknownNode (System.Object o, System.String qnames) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReader.UnknownNode (System.Object o) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadListElement (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, System.Object list, Boolean canCreateInstance) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadObject (System.Xml.Serialization.XmlTypeMapping typeMap, Boolean isNullable, Boolean checkType) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadRoot (System.Xml.Serialization.XmlTypeMapping rootMap) [0x00000] in :0 at System.Xml.Serialization.XmlSerializationReaderInterpreter.ReadRoot () [0x00000] in :0 at System.Xml.Serialization.XmlSerializer.Deserialize (System.Xml.Serialization.XmlSerializationReader reader) [0x00000] in :0

GetFilePath returns path of the file. In file is Xml document. Content is: <?xml version="1.0" encoding="utf-8"?> <ArrayOfBusinessOffer xmlns:xsi="w3.org/2001/XMLSchema-instance" xmlns:xsd="w3.org/2001/XMLSchema"> <BusinessOffer> </BusinessOffer> </ArrayOfBusinessOffer> — MasterMedia
– MasterMedia, Commented Dec 16, 2013 at 13:53
And are you sure that GetFilePath itself is doing the right thing? Have you debugged through to check that? — Jon Skeet
– Jon Skeet, Commented Dec 16, 2013 at 14:00
Yes, I have debugged GetFilePath. I can get the content of xml file like this string text = File.ReadAllText (path). The correct content of xml file without semicolons is <?xml version="1.0" encoding="utf-8"?> <ArrayOfBusinessOffer xmlns:xsi="w3.org/2001/XMLSchema-instance" xmlns:xsd="w3.org/2001/XMLSchema"> <BusinessOffer> </BusinessOffer> </ArrayOfBusinessOffer> — MasterMedia
– MasterMedia, Commented Dec 16, 2013 at 14:21

Dave · Accepted Answer · 2013-12-16 14:02:19Z

1

The XML you've pasted is invalid. I tried pasting it into Notepad, saving as test.xml and opening in Chrome. It looks like it doesn't like the semicolons. I took them out to leave me with the following which opened fine:

<?xml version="1.0" encoding="utf-8"?>
<ArrayOfBusinessOffer xmlns:xsi="w3.org/2001/XMLSchema-instance" xmlns:xsd="w3.org/2001/XMLSchema">
<BusinessOffer>
</BusinessOffer>
</ArrayOfBusinessOffer>

answered Dec 16, 2013 at 14:02

Dave

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MasterMedia Over a year ago

I continue get System.NullReferenceException. What can be the cause?

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