C# 从基类继承实例值
假设您有这样的类关系：C# 从基类继承实例值,c#,oop,C#,Oop,假设您有这样的类关系： class Banana : Fruit { } public class Fruit { public int Price { get; set; } public string Origins { get; set; } } public class Banana : Fruit { public string peelDensity; public static Banana AsBanana(Fruit f) {
class Banana : Fruit { }
public class Fruit
{
public int Price { get; set; }
public string Origins { get; set; }
}
public class Banana : Fruit
{
public string peelDensity;
public static Banana AsBanana(Fruit f)
{
return f as Banana ?? new Banana { Price = f.Price, Origins = f.Origins };
}
}
Banana b = Banana.AsBanana( myFruit);
class Fruit
{
public int price;
public string origins;
}
class banana : fruit
{
public string peelDensity;
public Fruit (peelDensity p, int pr, string o)
{
peelDensity = p;
price = pr;
o = origins;
}
}
价格产地banana b = new banana(peel, price, origins);
public Banana(Fruit fruit)
{
Price = fruit.Price;
Origin = fruit.Origin;
}
Fruit apple = new Fruit(50, "some origin");
Banana banana = new Banana(apple);
公共香蕉（水果）{this=水果；}以上只是一些伪代码。在我的项目中，我的Fruit类已经分配了20多个值，Banana类应该继承所有这些值，但我想知道是否有更好的方法来编写更优雅的构造函数类。当我理解您的问题时，我认为您与此相关：
This is your base class
public class Fruit{
public double Price { get; set; }
public string Origins { get; set; }
//or you can create a constructor
//one default constructor
public virtual void GetPrice()
{
Price = 69;
}
}
public class Banana : Fruit{
public string peelDensity { get; set; }
//this is a sample of Default Constructor
public Banana()
:base()
{
Price = 0; //here you're setting default value to banana once it's initialized
}
public override void GetPrice()
{
//base.GetPrice(); //here you get the value from the Parent Class
Price = 100; // here you're setting a value for the price of Banana once you call this method;
}
}
只需添加一些提示，因为您的Fruit类非常通用，您可以将其设置为一个抽象类（可以与其子类一起继承的抽象方法的集合），但有许多方法可以抽象类，并且只要在需要时为构造函数设置默认值即可，通过使用复制构造函数和工厂方法 复制构造函数：
public Banana(Fruit fruit)
{
Price = fruit.Price;
Origin = fruit.Origin;
}
Fruit apple = new Fruit(50, "some origin");
Banana banana = new Banana(apple);
public static class FruitFactory
{
public static Banana BananaFromFruit(Fruit fruit)
{
return new Banana(fruit.Price, fruit.Origin);
}
}
Fruit apple = new Fruit(50, "some origin");
Banana banana = FruitFactory.BananaFromFruit(apple);
请注意，我修改了类及其属性的大小写，以遵循c#约定。正如@JC Borlagdan提到的另一种方法是创建一个香蕉工厂，该工厂反过来创建具有某些预设属性的香蕉对象。 然后，每个继承都有一个单独的工厂，负责默认属性 您可以简单地用谷歌搜索工厂模式。有很多例子和解释 工厂也可以是一种方法，不必存在于类中。 下面是一个小例子：
class BananaFactory {
public int price;
public string origins;
Banana CreateBanana() {
return new Banana(){
peelDensity = "SomeValue",
price = price,
origins = origins
};
}
}
var banana = bananaFactoryinstance.CreateBanana();
// banana has price and origins that are set in the factory
你可以这样做：
class Banana : Fruit { }
public class Fruit
{
public int Price { get; set; }
public string Origins { get; set; }
}
public class Banana : Fruit
{
public string peelDensity;
public static Banana AsBanana(Fruit f)
{
return f as Banana ?? new Banana { Price = f.Price, Origins = f.Origins };
}
}
Banana b = Banana.AsBanana( myFruit);
class Banana : Fruit { }
public class Fruit
{
public int Price { get; set; }
public string Origins { get; set; }
}
public class Banana : Fruit
{
public string peelDensity;
public static Banana AsBanana(Fruit f)
{
return f as Banana ?? new Banana { Price = f.Price, Origins = f.Origins };
}
}
Banana b = Banana.AsBanana( myFruit);
香蕉始终可以指定给声明为水果的变量，但反之亦然。这是面向对象开发的要点之一。它不能继承这一点。你需要把它们复制过来（也许是工厂方法？）我正努力理解你的问题。您能否提供一个说明如何填充这些值的示例？另外，请指定您期望的结果（但没有得到）。@nkosi您的意思是我应该在香蕉的构造函数中手动分配水果中的所有现有值吗？@DavidG我正在学习如何在我姑妈的计算机上编码。请不要吝啬。我们每天都在学习新的东西。@ina-C#没有“公共全球价值观”。听起来你还没有完全明白继承意味着什么。继承只是扩展类的定义，而不是扩展现有实例
bananafruitbananafruitpublicbanana（Fruit-Fruit）{this=Fruit；}