Question

我想弄清楚为什么分配器（myC.myself）在编译行后变为null？提前谢谢。

namespace AequalsBequalsC
{
  class Program
  {
    static void Main(string[] args)
    {
        A myA = new A();
        A myB = new A();
        myB.a = 8;
        A myC = new A();
        myC.a = 9;

        myC.myself = myA;
        myC = myC.myself;

        Console.WriteLine("myA.a is {0}, myB.a is {1}, myC.a is {2}", myA.a,myB.a, myC.a);

        Console.ReadLine();
    }
  }
  public class A
  {
    public int a = 4;
    public A myself;
  }
}

Answer 1

永远不会成为null。 始终为空。当您创建A类的新实例时，我自己variable永远不会被分配，因此是null。

当您将myC.myself myA值分配给myA，然后将myC值分配给myC时，myself不再是您创建的第三个对象，但第一个，从来没有class Program { static void Main(string[] args) { A myA = new A(); A myB = new A(); myB.a = 8; A myC = new A(); myC.a = 9; myC.myself = myA; myC = myC.myself; Console.WriteLine("myA.a is {0}, myB.a is {1}, myC.a is {2}", myA.a, myB.a, myC.a); Console.ReadLine(); } } public class A { public int a = 4; public A myself; public A() { this.myself = this; } }设置在第一位。

现在，如果您做了类似的事情（我强烈建议不要这样做），那么它就不会为空：

/*You can replace theTextFieldYouAreTalkingAbout with the one you are talking about*/

theTextFieldYouAreTalkingAbout.text = ""

为什么内部实例变为null

1 个答案: