1:利用反射实现
public static T DeepCopy<T>(T obj)
{
//如果是字符串或值类型则直接返回
if (obj is string || obj.GetType().IsValueType) return obj;
object retval = Activator.CreateInstance(obj.GetType());
FieldInfo[] fields = obj.GetType().GetFields(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Insta