Kann man vielleicht mal wieder brauchen: Constructor via Reflection kopieren
//copy constructor
public ClassName(Testclass testclass)
{
FieldInfo[] lFields = this.GetType().GetFields(BindingFlags.NonPublic
| BindingFlags.Public | BindingFlags.Instance);
foreach (FieldInfo fi in lFields)
fi.SetValue(this, fi.GetValue(testclass));
}