在程序启动时实例化一个随机类 [英] Instantiate a random class on program start

问题描述

我现在正忙着继承和其他一些概念。

I'm just having a play around with inheritance and a few other concepts at the moment.

我创建了一个控制台应用程序，其中包含以下类：

I have created a console app that amongst other things, holds the following classes:

Public abstract Organism

Public abstract Animal : Organism

Public Bird : Animal
Public Mammal : Animal
Public Reptile : Animal
Public Fish : Animal
Public Amphibian : Animal

Public Human : Organism

当控制台应用程序启动时，我想从Human，Fish，Mammal，Reptile，Bird或Amphibian类创建一个新对象。要实例化这些类中的哪一个是随机选择的。

When the console app starts, I want to create a new object from either the Human, Fish, Mammal, Reptile, Bird or Amphibian class. Which one of these classes to instantiate is to be randomly chosen.

一旦随机选择了一个类，我就使用console.writeline来询问用户关键问题，以便为给定的对象属性赋值。

Once a class has been randomly chosen, I've used console.writeline to ask the user key questions to assign values to the given objects properties.

如何从这些类中的一个创建随机对象？

How do I create a random object from one of these classes?

推荐答案

// use the DLL of the project which is currently running
var runningAssembly = Assembly.GetExecutingAssemby();

// all classes have a "Type" which exposes information about the class
var organismType = typeof(Organism);

// to keep track of all organism classes that we've found.
var allOrganismTypes = new List<Type>();

// go through all types in our project and locate those who inherit our 
// organism class
foreach (var type in runningAssembly.GetTypes())
{
    if (organismType.IsAssignableFrom(type))
        allOrganismTypes.Add(type);
}

// Find a random index here (do it yourself)
var theRandomIndex = 10;


var selectedType = allOrganismTypes[theRandomIndex];

// activator is a class in .NET which can create new objects 
// with the help of a type
var selected = (Organism)Activator.CreateInstance(selectedType);

代码中有一些错误，你必须自己纠正。

There are some "mistakes" in the code that you have to correct yourself.

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