C#

public struct Struct1
{
    private string s;
    public Struct1(string d)
    {
        s = "";
    }
    public void SetS(string i) { s = i; }
    public string GetS() { return s; }
}

class myStr
{
    private string s;
    public myStr(){}
    public void SetS(string i) { s = i; }
    public string GetS() { return s; }
}

static void Main(string[] args)
{
    List<Struct1> ls = new List<Struct1>();
    Struct1 str = new Struct1("f");
    ls.Add(str);
    ls[0].SetS("hi");
    string mys = ls[0].GetS();
    Console.WriteLine("mys: " + mys);

    List<myStr> ls2 = new List<myStr>();
    myStr str2 = new myStr();
    ls2.Add(str2);
    ls2[0].SetS("hello");
    string mys2 = ls2[0].GetS();
    Console.WriteLine("mys2: " + mys2);
}

if (mChildNode.FirstChild.Value != string.Empty)
{
   byte[] byteData = System.Convert.FromBase64String(mChildNode.FirstChild.Value);
   MemoryStream stream = new MemoryStream(byteData);
   mImage = new Bitmap(stream);
   stream.Close();
   stream.Dispose();
   stream = null;
   Array.Clear(byteData, 0, byteData.Length);
   byteData = null;

   mChildNode.FirstChild.Value = "";
   mChildNode.FirstChild.Value = null;
}