XmlSerializer throws an exception on enum

Question

With the following Code the XmlSerializer throws an expection because Foo contains two Properties with the same name of the enum EnumSameName .

Framework .NET 4.0

public class Bar1
{
    public enum EnumSameName
    {
        a
    }

    public EnumSameName MyBar1Enum { get; set; }
}

public class Bar2
{
    public enum EnumSameName
    {
        b
    }

    public EnumSameName MyBar2Enum { get; set; }
}

public class Foo
{
    public Foo()
    {
        MyEnum1 = new Bar1();
        MyEnum2 = new Bar2();
    }

    public Bar1 MyEnum1 { get; set; }

    public Bar2 MyEnum2 { get; set; }
}

Now try to serialize Foo

var parameter = new Foo();
var serializer = new XmlSerializer(parameter.GetType()); 
// ERROR System.InvalidOperationException: [...]

After rename one of the EnumSameName everything works as expected.

Where does this error come from?

Answer 1

The error message in question should read

Types 'Bar2.EnumSameName' and 'Bar1.EnumSameName' both use the XML type name, 'EnumSameName', from namespace ''. Use XML attributes to specify a unique XML name and/or namespace for the type.

Have a look at

XML Namespace Collisions, XmlNodeList and Deserialization, and More

You can try to change the code to

[XmlRoot("Bar1", Namespace = "http://example.com/schemas/Bar1")]
public class Bar1
{
    [XmlRoot("Bar1EnumSameName", Namespace = "http://example.com/schemas/Bar1")]
    public enum EnumSameName
    {
        a
    }

    public EnumSameName Mode { get; set; }
}

[XmlRoot("Bar2", Namespace = "http://example.com/schemas/Bar2")]
public class Bar2
{
    [XmlRoot("Bar2EnumSameName", Namespace = "http://example.com/schemas/Bar2")]
    public enum EnumSameName
    {
        b
    }

    public EnumSameName Mode { get; set; }
}

As an after thought, just adding the XmlRoot documentation

Controls XML serialization of the attribute target as an XML root element.