C# Object Initialization[完整版]

C# Object Initialization[完整版]2011-05-23原文地址:http://www.csharp411.com/c-object-initialization/

当构造一个C#对象时,理解对象的作用域和构造器被初始化的序列是很重要的

Derived static fields

Derived static constructor

Derived instance fields

Base static fields

Base static constructor

Base instance fields

Base instance constructor

Derived instance constructor

示例

下面的是一个C#控制台程序的例子，这个例子演示了对象初始化的次序

这个程序创建基对象的派生对象,包含了静态化和实例化构造器以及作用域,两个作用域"Field1"和"Field2"在他们的定义里被初始化,然而 "Field3"在构造器里被初始化.同时也包含了一个证明为什么不能从构造器里调用虚方法的虚方法.当每个作用域和构造器被初始化时就会写入控制台,因此你可以看到初始化的序列

using System;

namespace ObjectInit
{
  class Program
  {
    static void Main（ string[] args ）
    {
      Derived d = new Derived（）;
      Console.ReadLine（）;
    }
  }
  class Base
  {
    public Base（）
    {
      Console.WriteLine（ "Base.Instance.Constructor" ）;
      this.m_Field3 = new Tracker（ "Base.Instance.Field3″ ）;
      this.Virtual（）;
    }
    static Base（）
    {
      Console.WriteLine（ "Base.Static.Constructor" ）;
    }
    private Tracker m_Field1 = new Tracker（ "Base.Instance.Field1″ ）;
    private Tracker m_Field2 = new Tracker（ "Base.Instance.Field2″ ）;
    private Tracker m_Field3;
    static private Tracker s_Field1 = new Tracker（ "Base.Static.Field1″ ）;
    static private Tracker s_Field2 = new Tracker（ "Base.Static.Field2″ ）;
    virtual public void Virtual（）
    {
      Console.WriteLine（ "Base.Instance.Virtual" ）;
    }
  }
  class Derived : Base
  {
    public Derived（）
    {
      Console.WriteLine（ "Derived.Instance.Constructor" ）;
      this.m_Field3 = new Tracker（ "Derived.Instance.Field3″ ）;
    }
    static Derived（）
    {
      Console.WriteLine（ "Derived.Static.Constructor" ）;
    }
    private Tracker m_Field1 = new Tracker（ "Derived.Instance.Field1″ ）;
    private Tracker m_Field2 = new Tracker（ "Derived.Instance.Field2″ ）;
    private Tracker m_Field3;
    static private Tracker s_Field1 = new Tracker（ "Derived.Static.Field1″ ）;
    static private Tracker s_Field2 = new Tracker（ "Derived.Static.Field2″ ）;
    override public void Virtual（）
    {
      Console.WriteLine（ "Derived.Instance.Virtual" ）;
    }
  }
  class Tracker
  {
    public Tracker（ string text ）
    {
      Console.WriteLine（ text ）;
    }
  }
}