官方教學 : Lessons 01 - Inheritance(繼承)

官方教學網址 : http://unity3d.com/learn/tutorials/modules/intermediate/scripting/inheritance

Fruit Class

using UnityEngine;
using System.Collections;

//This is the base class which is
//also known as the Parent class.
public class Fruit
{
    public string color;
 
    //This is the first constructor for the Fruit class
    //and is not inherited by any derived classes.
    public Fruit()
    {
        color = "orange";
        Debug.Log("1st Fruit Constructor Called");
    }
 
    //This is the second constructor for the Fruit class
    //and is not inherited by any derived classes.
    public Fruit(string newColor)
    {
        color = newColor;
        Debug.Log("2nd Fruit Constructor Called");
    }
 
    public void Chop()
    {
        Debug.Log("The " + color + " fruit has been chopped.");  
    }
 
    public void SayHello()
    {
        Debug.Log("Hello, I am a fruit.");
    }
}

Apple Class

using UnityEngine;
using System.Collections;

//This is the derived class whis is
//also know as the Child class.
public class Apple : Fruit
{
    //This is the first constructor for the Apple class.
    //It calls the parent constructor immediately, even
    //before it runs.
    public Apple()
    {
        //Notice how Apple has access to the public variable
        //color, which is a part of the parent Fruit class.
        color = "red";
        Debug.Log("1st Apple Constructor Called");
    }
 
    //This is the second constructor for the Apple class.
    //It specifies which parent constructor will be called
    //using the "base" keyword.
    public Apple(string newColor) : base(newColor)
    {
        //Notice how this constructor doesn't set the color
        //since the base constructor sets the color that
        //is passed as an argument.
        Debug.Log("2nd Apple Constructor Called");
    }
}

FruitSalad Class

using UnityEngine;

using System.Collections;

public class FruitSalad : MonoBehaviour 

{

    void Start () 

    {

        //Let's illustrate inheritance with the 

        //default constructors.

        Debug.Log("Creating the fruit");

        Fruit myFruit = new Fruit();

        Debug.Log("Creating the apple");

        Apple myApple = new Apple();

        

        //Call the methods of the Fruit class.

        myFruit.SayHello();

        myFruit.Chop();

        

        //Call the methods of the Apple class.

        //Notice how class Apple has access to all

        //of the public methods of class Fruit.

        myApple.SayHello();

        myApple.Chop();

        

        //Now let's illustrate inheritance with the 

        //constructors that read in a string.

        Debug.Log("Creating the fruit");

        myFruit = new Fruit("yellow");

        Debug.Log("Creating the apple");

        myApple = new Apple("green");

        

        //Call the methods of the Fruit class.

        myFruit.SayHello();

        myFruit.Chop();

        

        //Call the methods of the Apple class.

        //Notice how class Apple has access to all

        //of the public methods of class Fruit.

        myApple.SayHello();

        myApple.Chop();

    }

}