从.net中的现有基础对象创建派生对象

Person person = new Employee(); // for some reason
...
Employee emp = (Employee)person;

如果这个人只是一个人:你不能;你可以让雇员 概括 这个人——或者你可以 字段:

class Employee { // encapsulation
  private readonly Person person;
  public Person {get {return person;}}
  public Employee(Person person) {this.person = person;}
  public Employee() : this(new Person()) {}
}

class Employee : Person { // inheritance
  public Employee(Person person) : base(person) {}
  public Employee() {}
}
class Person {
    public Person(Person template) {
        this.Name = template.Name; // etc
    }
    public Person() {}
}