DataContract serialization of property of "Type"

Question

How can I effectively serialize a property of type "Type" in my DataContract attributed class? I'm assuming that Type is a non-serializable Type (wow that's getting silly sounding.) I'm sure that there is a way to do this that meets my needs. Basically I need to serialize the name of a type for a factory method to effectively construct, but I don't want to expose it as a string, I want a Type.

I know there are a number of ways to do this, I'm curious what other methods are known at this time.

EDIT: I just realized it may be something else causing it but here is the error, and below I have the class definition.

Type 'System.RuntimeType' with data contract name 'RuntimeType:http://schemas.datacontract.org/2004/07/System' is not expected. Consider using a DataContractResolver or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to DataContractSerializer.

[DataContract]
public class PlottingDeviceInfo : ObservableObject
{
    private string _deviceName;
    [DataMember]
    public string DeviceName
    {
        get
        {
            return _deviceName;
        }
        set
        {
            Set(() => DeviceName, ref _deviceName, value);
        }
    }

    private Type _deviceType;
    [DataMember]
    public Type DeviceType
    {
        get
        {
            return _deviceType;
        }
        set
        {
            Set(() => DeviceType, ref _deviceType, value);
        }
    }

    private DeviceSettingsInfo _settings;
    [DataMember]
    public DeviceSettingsInfo Settings
    {
        get
        {
            return _settings;
        }
        set
        {
            Set(() => Settings, ref _settings, value);
        }
    }

    private DeviceChannelInfo _channel;
    [DataMember]
    public DeviceChannelInfo Channel
    {
        get
        {
            return _channel;
        }
        set
        {
            Set(() => Channel, ref _channel, value);
        }
    }

    private DeviceCategory _deviceCategory;
    [IgnoreDataMember]
    public DeviceCategory DeviceCategory
    {
        get
        {
            return _deviceCategory;
        }
        set
        {
            Set(() => DeviceCategory, ref _deviceCategory, value);
        }
    }
}

Here is the base class, used to add observability for viewmodel consumption.

[DataContract]
public class ObservableObject : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    [IgnoreDataMember]
    protected PropertyChangedEventHandler PropertyChangedHandler
    {
        get
        {
            return PropertyChanged;
        }
    }

    [Conditional("DEBUG")]
    [DebuggerStepThrough]
    public void VerifyPropertyName(string propertyName)
    {
        var myType = this.GetType();
        if (!string.IsNullOrEmpty(propertyName)
            && myType.GetProperty(propertyName) == null)
        {
            throw new ArgumentException("Property not found", propertyName);
        }
    }

    protected virtual void RaisePropertyChanged(string propertyName)
    {
        VerifyPropertyName(propertyName);

        var handler = PropertyChanged;

        if (handler != null)
        {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    protected virtual void RaisePropertyChanged<T>(Expression<Func<T>> propertyExpression)
    {
        if (propertyExpression == null)
        {
            return;
        }

        var handler = PropertyChanged;

        if (handler != null)
        {
            var body = propertyExpression.Body as MemberExpression;
            handler(this, new PropertyChangedEventArgs(body.Member.Name));
        }
    }

    protected void Set<T>(
        Expression<Func<T>> propertyExpression,
        ref T field,
        T newValue)
    {
        if (EqualityComparer<T>.Default.Equals(field, newValue))
        {
            return;
        }

        field = newValue;
        RaisePropertyChanged(propertyExpression);
    }

    protected void Set<T>(
        string propertyName,
        ref T field,
        T newValue)
    {
        if (EqualityComparer<T>.Default.Equals(field, newValue))
        {
            return;
        }

        field = newValue;
        RaisePropertyChanged(propertyName);
    }
}

Answer 1

Type cannot be expressed in a cross-platform way, so it has no inbuilt representation. Your best bet is to represent it as a string, i.e.

public Type DeviceType { get; set; }
[DataMember(Name="DeviceType")]
private string DeviceTypeName {
    get { return DeviceType == null ? null : DeviceType.AssemblyQualifiedName; }
    set { DeviceType = value == null ? null : Type.GetType(value); }
}