Csharp/CSharp Tutorial/Class/base — различия между версиями

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Текущая версия на 12:16, 26 мая 2010

a subclass uses the keyword base to invoke a particular subclass constructor

using System;
public class Class1 {
    public static void Main(string[] args) {
        SubClass sc1 = new SubClass();
        SubClass sc2 = new SubClass(1, 2);
    }
}
public class BaseClass {
    public BaseClass() {
        Console.WriteLine("Constructing BaseClass (default)");
    }
    public BaseClass(int i) {
        Console.WriteLine("Constructing BaseClass({0})", i);
    }
}
public class SubClass : BaseClass {
    public SubClass() {
        Console.WriteLine("Constructing SubClass (default)");
    }
    public SubClass(int i1, int i2)
        : base(i1) {
        Console.WriteLine("Constructing SubClass({0}, {1})",
                                                  i1, i2);
    }
}

Use base keyword to access field in the base class

using System;
class BaseClass                                      
{
   public string Field1 = "In the base class";
}
class DerivedClass : BaseClass                        
{
   new public string Field1 = "In the derived class";
   public void Display()
   {
      Console.WriteLine("{0}", Field1);              // Access the derived class.
      Console.WriteLine("{0}", base.Field1);         // Access the base class.
   }
}
class Program
{
   static void Main()
   {
      DerivedClass oc = new DerivedClass();
      oc.Display();
   }
}
In the derived class
In the base class

Using base to Access a Hidden Name

"base" refers to the base class of the derived class in which it is used.

This usage has the following general form:


base.member