C# 二进制序列化、静态和单例
在让我的类进行二进制序列化之后,对另一个类中断的静态实例的任何引用。 这个例子应该更好地解释我的意思:C# 二进制序列化、静态和单例,c#,serialization,static,singleton,binary-serialization,C#,Serialization,Static,Singleton,Binary Serialization,在让我的类进行二进制序列化之后,对另一个类中断的静态实例的任何引用。 这个例子应该更好地解释我的意思: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.IO; using System.Runtime.Serialization.Formatters.Binary; namespace staticorsingletontest { [
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
namespace staticorsingletontest
{
[System.Serializable]
public class weapon
{
public string name;
public weapon (string name)
{ this.name = name; }
}
class Program
{
public static weapon sword = new weapon("Sword");
public static weapon axe = new weapon("Axe");
static void Main(string[] args)
{
byte[] b;
Dictionary<weapon, int> WarriorSkills = new Dictionary<weapon,int>();
Dictionary<weapon, int> Des = new Dictionary<weapon,int>();
WarriorSkills.Add(sword, 10);
using (MemoryStream ms = new MemoryStream())
{
//Serialize
new BinaryFormatter().Serialize(ms, WarriorSkills);
b = ms.ToArray();
//Deserialize
ms.Flush();
ms.Write(b, 0, b.Length);
ms.Seek(0, SeekOrigin.Begin);
Des = (Dictionary<weapon, int>)new BinaryFormatter().Deserialize(ms);
}
Console.WriteLine(WarriorSkills.Keys.ToArray()[0].name + " is a " + Des.Keys.ToArray()[0].name + ", but are they equal? " + (WarriorSkills.Keys.ToArray()[0] == Des.Keys.ToArray()[0]).ToString());
Console.ReadLine();
Console.WriteLine("Warrior's Skill with Sword is ", Des[sword]); //wonderful "KeyNotFoundException" error
Console.ReadLine();
}
}
}
使用系统;
使用System.Collections.Generic;
使用System.Linq;
使用系统文本;
使用System.IO;
使用System.Runtime.Serialization.Formatters.Binary;
命名空间staticorSingleContest
{
[系统可序列化]
公营武器
{
公共字符串名称;
公共武器(字符串名称)
{this.name=name;}
}
班级计划
{
公共静态武器剑=新武器(“剑”);
公共静态武器斧头=新武器(“斧头”);
静态void Main(字符串[]参数)
{
字节[]b;
字典WarriorSkills=新字典();
字典Des=新字典();
战斗技能。增加(剑,10);
使用(MemoryStream ms=new MemoryStream())
{
//连载
新的BinaryFormatter().Serialize(ms、WarriorSkills);
b=托雷女士();
//反序列化
弗拉什女士();
ms.Write(b,0,b.长度);
Seek女士(0,SeekOrigin.Begin);
Des=(字典)新的BinaryFormatter()。反序列化(ms);
}
Console.WriteLine(WarriorSkills.Keys.ToArray()[0].name+“是一个“+Des.Keys.ToArray()[0].name+”,但它们相等吗?+(WarriorSkills.Keys.ToArray()[0]==Des.Keys.ToArray()[0]).ToString();
Console.ReadLine();
Console.WriteLine(“战士的剑术是”,Des[剑]);//奇妙的“KeyNotFoundException”错误
Console.ReadLine();
}
}
}
程序抛出错误,因为反序列化的“剑”不是同一个“剑”(它的静态,这是怎么发生的?)
制造武器
a级单体武器
不起作用,因为这样剑和斧头就成了一回事
有没有办法指出这两把剑是同一件事,或者我没有得到一些静态类的核心逻辑?也许解决这个问题的最好办法是根本避免序列化武器
相反,您可以序列化武器密钥,并使用类型安全枚举来查找武器
但是,在使用.NET二进制序列化作为持久机制之前,应该考虑其他所有选项——它执行得很差,并且有大量的GOTCHA会真正伤害您——特别是如果您试图保持版本向后兼容性。
[Serializable]
public sealed class Warrior
{
private readonly Dictionary<int, int> weaponSkills = new Dictionary<int, int>();
public void SetWeaponSkill(Weapon weapon, int skill)
{
weaponSkills[weapon.Key] = skill;
}
public int GetWeaponSkill(Weapon weapon)
{
int skill;
if (!weaponSkills.TryGetValue(weapon.Key, out skill))
{
throw new ArgumentException("Warrior doesn't have weapon");
}
return skill;
}
}
public static class Weapons
{
public static readonly Weapon Sword = new Weapon(1, "Sword");
public static readonly Weapon Dagger = new Weapon(2, "Dagger");
}
public sealed class Weapon
{
public Weapon(int key, string text)
{
Key = key;
Text = text;
}
public int Key { get; }
public string Text { get; }
}
[可序列化]
公印级战士
{
私有只读字典weaponSkills=新字典();
公共无效设置武器技能(武器武器,智力技能)
{
武器技能[武器.钥匙]=技能;
}
公共智力获取武器技能(武器)
{
智力技能;
if(!weaponSkills.TryGetValue(weapon.Key,out skill))
{
抛出新的异常(“战士没有武器”);
}
回击技术;
}
}
公共静态类武器
{
公共静态只读武器剑=新武器(1,“剑”);
公共静态只读武器匕首=新武器(2,“匕首”);
}
公共密封类武器
{
公共武器(int键,字符串文本)
{
钥匙=钥匙;
文本=文本;
}
公共int密钥{get;}
公共字符串文本{get;}
}
也许解决这个问题的最好办法是根本避免序列化武器
相反,您可以序列化武器密钥,并使用类型安全枚举来查找武器
但是,在使用.NET二进制序列化作为持久机制之前,应该考虑其他所有选项——它执行得很差,并且有大量的GOTCHA会真正伤害您——特别是如果您试图保持版本向后兼容性。
[Serializable]
public sealed class Warrior
{
private readonly Dictionary<int, int> weaponSkills = new Dictionary<int, int>();
public void SetWeaponSkill(Weapon weapon, int skill)
{
weaponSkills[weapon.Key] = skill;
}
public int GetWeaponSkill(Weapon weapon)
{
int skill;
if (!weaponSkills.TryGetValue(weapon.Key, out skill))
{
throw new ArgumentException("Warrior doesn't have weapon");
}
return skill;
}
}
public static class Weapons
{
public static readonly Weapon Sword = new Weapon(1, "Sword");
public static readonly Weapon Dagger = new Weapon(2, "Dagger");
}
public sealed class Weapon
{
public Weapon(int key, string text)
{
Key = key;
Text = text;
}
public int Key { get; }
public string Text { get; }
}
[可序列化]
公印级战士
{
私有只读字典weaponSkills=新字典();
公共无效设置武器技能(武器武器,智力技能)
{
武器技能[武器.钥匙]=技能;
}
公共智力获取武器技能(武器)
{
智力技能;
if(!weaponSkills.TryGetValue(weapon.Key,out skill))
{
抛出新的异常(“战士没有武器”);
}
回击技术;
}
}
公共静态类武器
{
公共静态只读武器剑=新武器(1,“剑”);
公共静态只读武器匕首=新武器(2,“匕首”);
}
公共密封类武器
{
公共武器(int键,字符串文本)
{
钥匙=钥匙;
文本=文本;
}
公共int密钥{get;}
公共字符串文本{get;}
}
如果反序列化(最初是单例)对象,它无论如何都将是一个新实例,除非指定反序列化应返回“已知”实例。但您可以通过一些定制来实现:
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
public class Example
{
[Serializable]
public class Weapon: IObjectReference // here is the trick, see GetRealObject method
{
// unless you want to allow to create any kind of weapon I suggest to use an enum for the predefined types
private enum WeaponKind { Sword, Axe }
public static Weapon Sword { get; } = new Weapon(WeaponKind.Sword);
public static Weapon Axe { get; } = new Weapon(WeaponKind.Axe);
// this is the only instance field so this will be stored on serialization
private readonly WeaponKind kind;
public string Name => kind.ToString();
// make the constructor private so no one can create further weapons
private Weapon(WeaponKind kind)
{
this.kind = kind;
}
// on deserialization ALWAYS a new instance will be created
// but if you implement IObjectReference, this method will be called before returning the deserialized object
public object GetRealObject(StreamingContext context)
{
// map the temporarily created new deserialized instance to the well-known static member:
switch (kind)
{
case WeaponKind.Sword:
return Sword;
case WeaponKind.Axe:
return Axe;
default:
throw new InvalidOperationException("Unknown weapon type");
}
}
}
}
还有一些测试:
public static void Main()
{
var axe = Weapon.Axe;
var savedContent = new MemoryStream();
var formatter = new BinaryFormatter();
formatter.Serialize(savedContent, axe);
savedContent.Position = 0;
var deserializedAxe = (Weapon)formatter.Deserialize(savedContent);
Console.WriteLine(ReferenceEquals(axe, deserializedAxe)); // prints True
}
更新:
如果你所有的武器属性都是常量(如果有更多的实例应该被认为是相等的,这不是问题),那么只需覆盖等于:
public override bool Equals(object obj)
{
var other = obj as Weapon;
if (other == null)
return base.Equals(obj);
return other.kind == this.kind;
}
如果覆盖Equals
也必须覆盖GetHashCode
,否则,将无法在字典中找到同一对象的不同实例:
public override int GetHashCode()
{
return kind.GetHashCode();
}
请注意,==
运算符仍将返回引用相等。如果要覆盖此选项,则需要重载==
和=代码>操作员:
public static bool operator ==(Weapon w1, Weapon w2)
{
return Equals(w1, w2);
}
public static bool operator !=(Weapon w1, Weapon w2)
{
return !Equals(w1, w2);
}
如果反序列化一个(最初是单例的)对象,它无论如何都将是一个新实例,除非您指定反序列化应该返回一个“已知”实例。但您可以通过一些定制来实现:
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
public class Example
{
[Serializable]
public class Weapon: IObjectReference // here is the trick, see GetRealObject method
{
// unless you want to allow to create any kind of weapon I suggest to use an enum for the predefined types
private enum WeaponKind { Sword, Axe }
public static Weapon Sword { get; } = new Weapon(WeaponKind.Sword);
public static Weapon Axe { get; } = new Weapon(WeaponKind.Axe);
// this is the only instance field so this will be stored on serialization
private readonly WeaponKind kind;
public string Name => kind.ToString();
// make the constructor private so no one can create further weapons
private Weapon(WeaponKind kind)
{
this.kind = kind;
}
// on deserialization ALWAYS a new instance will be created
// but if you implement IObjectReference, this method will be called before returning the deserialized object
public object GetRealObject(StreamingContext context)
{
// map the temporarily created new deserialized instance to the well-known static member:
switch (kind)
{
case WeaponKind.Sword:
return Sword;
case WeaponKind.Axe:
return Axe;
default:
throw new InvalidOperationException("Unknown weapon type");
}
}
}
}
还有一些测试:
public static void Main()
{
var axe = Weapon.Axe;
var savedContent = new MemoryStream();
var formatter = new BinaryFormatter();
formatter.Serialize(savedContent, axe);
savedContent.Position = 0;
var deserializedAxe = (Weapon)formatter.Deserialize(savedContent);
Console.WriteLine(ReferenceEquals(axe, deserializedAxe)); // prints True
}
更新:
如果你所有的武器属性都是常量(这不是问题