Deserialize dictionary with datacontractserializer c#

I want to deserialize a dictionary with datacontractserializer, the xml schema is the following :


<General xmlns="http://schemas.datacontract.org/2004/07/MyProject" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<Mydictionary xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
    <a:KeyValueOfunsignedByteMyclass>
        <a:Key>1a:Key>
        <a:Value>
                     ....
        a:Value>
    a:KeyValueOfunsignedByteMyclass>
    <a:KeyValueOfunsignedByteMyclass>
        <a:Key>2a:Key>
        <a:Value>
                    ....
        a:Value>
    a:KeyValueOfunsignedByteMyclass>
Mydictionary>

But on deserializing, I get this error :

"An item with the same key has already been added."

(referencing KeyValueOfunsignedByteMyclass)

Can someone help me to resolve this problem please?

Thanks

Apart from the separate first line (which looks invalid to me), I was able to reproduce that XML document and then deserialize it back using the following code:

using System;

using System.Collections.Generic;

using System.Xml;

using System.Runtime.Serialization;

[DataContract(Namespace="")]

public class MyClass

{

}

[CollectionDataContract(ItemName="KeyValueOfunsignedByteMyclass", Namespace="http://schemas.microsoft.com/2003/10/Serialization/Arrays")]

public class Mydictionary : Dictionary

{

}

class Test

{

static void Main()

{

Mydictionary myDict = new Mydictionary();

myDict.Add(1, new MyClass());

myDict.Add(2, new MyClass());

XmlWriterSettings settings = new XmlWriterSettings();

settings.Indent = true;

settings.OmitXmlDeclaration = true;

string fileName = "MyDictionary.xml";

XmlWriter writer = XmlWriter.Create(fileName, settings);

DataContractSerializer serializer = new DataContractSerializer(typeof(Mydictionary));

serializer.WriteStartObject(writer, myDict);

writer.WriteAttributeString("xmlns", "a", null, "http://schemas.microsoft.com/2003/10/Serialization/Arrays");

serializer.WriteObjectContent(writer, myDict);

serializer.WriteEndObject(writer);

writer.Close();

XmlReader reader = XmlReader.Create(fileName);

Mydictionary result = (Mydictionary)serializer.ReadObject(reader);

reader.Close();

foreach(byte b in result.Keys) Console.WriteLine(b);

Console.ReadKey();

}

}

The resulting XML is:

The console output (as expected) is:

1
2

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Apart from the separate first line (which looks invalid to me), I was able to reproduce that XML document and then deserialize it back using the following code:

using System;
using System.Collections.Generic;
using System.Xml;
using System.Runtime.Serialization;

[DataContract(Namespace="")]
public class MyClass
{
}

[CollectionDataContract(ItemName="KeyValueOfunsignedByteMyclass", Namespace="http://schemas.microsoft.com/2003/10/Serialization/Arrays")]
public class Mydictionary : Dictionary
{
}

class Test
{
static void Main()
{
Mydictionary myDict = new Mydictionary();
myDict.Add(1, new MyClass());
myDict.Add(2, new MyClass());

XmlWriterSettings settings = new XmlWriterSettings();
settings.Indent = true;
settings.OmitXmlDeclaration = true;
string fileName = "MyDictionary.xml";
XmlWriter writer = XmlWriter.Create(fileName, settings);
DataContractSerializer serializer = new DataContractSerializer(typeof(Mydictionary));
serializer.WriteStartObject(writer, myDict);
writer.WriteAttributeString("xmlns", "a", null, "http://schemas.microsoft.com/2003/10/Serialization/Arrays");
serializer.WriteObjectContent(writer, myDict);
serializer.WriteEndObject(writer);
writer.Close();

XmlReader reader = XmlReader.Create(fileName);
Mydictionary result = (Mydictionary)serializer.ReadObject(reader);
reader.Close();
foreach(byte b in result.Keys) Console.WriteLine(b);
Console.ReadKey();
}
}

The resulting XML is:

1

2

The console output (as expected) is:

1
2