public class Test 
{ 
    private InnerTest innerTest; 
    private int testNumber; 


    public Test() 
    { 
        this.innerTest = new InnerTest(); 
        this.testNumber = 5; 
    } 


    public int TestNumber1 
    { 
        get { return this.testNumber; } 
        set { this.testNumber = value;} 
    } 


    public InnerTest InnerTest 
    { 
        get { return this.innerTest; } 
        set { this.innerTest = value;} 
    } 


} 


public struct InnerTest 
{ 
    private int number; 


    public InnerTest(int number) 
    { 
        this.number = number; 
    } 
    public int Number{get { return number; }} 
}
	
[DataMember]
public int TestNumber1 
{ 
    get { return this.testNumber; } 
    set { this.testNumber = value;} 
} 

// note **not** a data-member
public InnerTest InnerTest 
{ 
    get { return this.innerTest; } 
    set { this.innerTest = value;} 
} 

[DataMember]
private int InnerTestValue
{
    get {return innerTest.Number;}
    set {innerTest = new InnerTest(value);}
}
	
Test test = new Test { TestNumber1 = 5 };

XmlSerializer xmlSer = new XmlSerializer(typeof(Test));
MemoryStream memStm = new MemoryStream();

xmlSer.Serialize(memStm, test);
	
StreamReader stmR = new StreamReader(memStm);
memStm.Position = 0;
string output = stmR.ReadToEnd();