2.反射

反射：System.Reflection .Net框架提供帮助类库 ，可以动态读取并使用metadata

Assembly assembly = Assembly.Load("Test");//dll名称 从当前目录加载
Assembly assembly1 = Assembly.LoadFrom("Test.dll");//带后缀或完整名称
Assembly assembly2 = Assembly.LoadFile(@"D:Test.dll");//完整路径的加载

Assembly assembly = Assembly.Load("");//加载dll
Type type = assembly.GetType("");//获取类型信息
object ob = Activator.CreateInstance(type);//创建对象

People people = new People();
Type typePeople = typeof(People);
Type typePeopleDTO = typeof(PeopleDTO);
people.ID = Guid.NewGuid();
people.Name = "测试";
people.Age = 3;
object peopleDTO = Activator.CreateInstance(typePeopleDTO);
foreach (var prop in typePeopleDTO.GetProperties())
{
      object value = typePeople.GetProperty(prop.Name).GetValue(people);
      prop.SetValue(peopleDTO, value);
}
foreach (var field in typePeopleDTO.GetFields())
{
      object value = typePeople.GetField(field.Name).GetValue(people);
      field.SetValue(peopleDTO, value);
}    

反射可以破坏单例，调用私有方法

典型：MVC就是通过反射调用方法

反射的优缺点：

优点：动态

缺点：1.写起来复杂；

　　　2.避开编译器的检查

　　　3.性能问题