博问 / 全部问题 / .NET技术 / C#

先看段可行的代码:

using System;

class Singleton
{
 private int use = 0;
 private int x;
 private int y;
 private static Singleton []instance;
 private static object lockHelp = new Object();
 private static int size;
 private Singleton()
 {}
 public static void Init(int x)
 {
  size = x;
  instance = new Singleton[size];
 }

 public static Singleton getInstance()
 {
  if(instance == null)
  {
   lock(lockHelp)
   {
    if(instance == null)
    {
     instance = new Singleton[10];
    }
   }
   
  }
  for(int i = 0; i < size; i++)
  {
   lock(lockHelp)
   {
    if(instance[i] == null)
    {
     instance[i] = new Singleton();
     instance[i].use = 1;
     return instance[i];
    }
    else
    {
     if(instance[i].use == 0)
     {
      instance[i].use = 1;
      return instance[i];
     }
    }
   }
  }
  return null;
 }
 public int X
 {
  get
  { return x; }
  set
  { x = value; }
 }
 public int Y
 {
  get
  { return y; }
  set
  {  y = value; }
 }
 public void dayin()
 {
  Console.WriteLine("这个实例的X为{0},Y为{1},使用计数为{2}", x, y, use);
  
 }
 public static void del(Singleton s)
 {
  for(int i = 0; i < size; i++)
  {
   if(instance[i] == s)
   {
    s = instance[i] = null;
    break;
   }
  }
 }
}

class Test
{
 public static void Main()
 {
  Singleton.Init(10);
  Sin

问题补充：class Test
{
public static void Main()
{
Singleton.Init(10);
Singleton s1 = Singleton.getInstance();
s1.X = 3;
s1.dayin();
Singleton s2 = Singleton.getInstance();
s2.dayin();
Singleton s3 = Singleton.getInstance();
s3.dayin();
Singleton s4 = Singleton.getInstance();
s4.dayin();
Singleton s5 = Singleton.getInstance();
s5.dayin();
Singleton s6 = Singleton.getInstance();
s6.dayin();
Singleton s7 = Singleton.getInstance();
s7.dayin();
Singleton s8 = Singleton.getInstance();
s8.dayin();
Singleton s9 = Singleton.getInstance();
s9.dayin();
Singleton s10 = Singleton.getInstance();
s10.dayin();
Singleton.del(s4);
Singleton s11 = Singleton.getInstance();
s11.dayin();
Console.ReadLine();
}
}
这样删除一个对象池中的对象有点麻烦,我希望直接设置 s1 = null;这一句话就OK
所以将函数改为:public static void getInstance(ref Singleton s)
外面:
public static void Main()
{
Singleton.Init(10);
Singleton s = null;
Singleton.getInstance(ref s);
s.dayin();
}
但出现未将对象的引用设置到对象的实例的错误
修改后的方法:
public static void getInstance(ref Singleton s)
{
if(instance == null)
{
lock(lockHelp)
{
if(instance == null)
{
instance = new Singleton[10];
}
}

}
for(int i = 0; i < size; i++)
{
lock(lockHelp)
{
if(instance[i] == null)
{
instance[i] = new Singleton();
instance[i].use = 1;
s = instance[i];
}
else
{
if(instance[i].use == 0)
{
instance[i].use = 1;
s = instance[i];
}
}
}
}
s = null;
}