c# - 从 AppDomain 获取静态列表

Question

我想访问将在 Class1 中创建的 Class2 的静态列表。

Class1 在一个 AppDomain 中加载，Class2 在另一个 AppDomain 中加载。但是如果我想访问 Class2 中的静态列表，我会得到两个不同的列表。

我认为我必须访问 Class1 中的同一个 AppDomain 才能获得 Class2，但是如果 Class1 的对象位于不同的 AppDomain 中，我该如何实现呢？

顺便说一下:没必要将 Class2 放在另一个 AppDomain 中，但我认为如果我这样做的话我可以得到相同的对象。

这是我的代码:

public class Class1 : MarshalByRefObject
{
    Class2 class2;

    public Class2 Class2
    {
        get { return class2; }
        set { class2 = value; }
    }
    public Class1()
    {
        AppDomain adc2 = AppDomain.CreateDomain("adc2");
        class2 = (Class2)adc2.CreateInstanceAndUnwrap(typeof(Class2).Assembly.FullName, typeof(Class2).FullName);
    }
}
public class Class2 : MarshalByRefObject
{
    static List<int> myIntegers = new List<int>();

    public static List<int> MyIntegers
    {
        get { return Class2.myIntegers; }
        set { Class2.myIntegers = value; }
    }
    public void AddInteger(int integer)
    {
        myIntegers.Add(integer);
    }
    public override string ToString()
    {
        StringBuilder sb = new StringBuilder();
        foreach (int integer in myIntegers)
        {
            sb.AppendLine(integer.ToString());
        }
        return sb.ToString();
    }
}

class Program
{
    static void Main(string[] args)
    {
        Type type1 = typeof(Class1);
        AppDomain ad1 = AppDomain.CreateDomain("ad1");
        Class1 ad1t1 = (Class1)ad1.CreateInstanceFromAndUnwrap(type1.Assembly.Location, type1.FullName);

        AppDomain ad2 = AppDomain.CreateDomain("ad2");
        Class1 ad2t1 = (Class1)ad2.CreateInstanceFromAndUnwrap(type1.Assembly.Location, type1.FullName);

        ad1t1.Class2.AddInteger(0);
        ad2t1.Class2.AddInteger(1);
        Console.WriteLine(ad1t1.Class2.ToString()); //Output: 0
        Console.WriteLine(ad2t1.Class2.ToString()); //Output: 1
        //
        Console.ReadKey();
    }
}

编辑

好吧，我发现我的插件加载器是罪魁祸首。如果您将使用不同的插件加载器(或至少一个加载器)，有人可以说为什么不能跨应用域工作吗？

如果所有文件都在一个程序集中，它将起作用(增量为 3)。在我的场景中(许多不同的程序集)我只得到 1,1,1

如果有人需要更多信息来帮助我，请随时提出要求。

示例 1(每个实例自己计算):

程序集:主要

PluginLoader.PluginLoader<IPlugin> pluginLoader1 = new PluginLoader.PluginLoader<IPlugin>(new DirectoryInfo(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location)));
IPlugin cl1 = pluginLoader1.Activate("MyLibrary.dll", "MyLibrary.Class1");
PluginLoader.PluginLoader<IPlugin> pluginLoader2 = new PluginLoader.PluginLoader<IPlugin>(new DirectoryInfo(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location)));
IPlugin cl3 = pluginLoader2.Activate("MyLibrary2.dll", "MyLibrary2.Class3");
//Increment() increases a static variable starting by 0
cl1.Increment();
Console.WriteLine(cl1.ToString()); //Output: 1
cl3.Increment();
Console.WriteLine(cl3.ToString()); //Output: 1

ClassLibrary2.Class2 class2 = new ClassLibrary2.Class2();
class2.Increment();
Console.WriteLine(class2.ToString()); //Output: 1

程序集:类库2

[Serializable]
public class Class2 : IPlugin
{
    public Class2() { }

    public override string ToString()
    {
        return incrementer.ToString();
    }
    static int incrementer = 0;
    public void Increment()
    {
        incrementer++;
    }
}

程序集:我的图书馆

public class Class1 : MarshalByRefObject, IPlugin
{
    Class2 class2;

    public Class2 Class2
    {
        get { return class2; }
        set { class2 = value; }
    }
    public Class1()
    {
        PluginLoader.PluginLoader<Class2> pluginLoader = new PluginLoader.PluginLoader<Class2>(new DirectoryInfo(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location)));
        class2 = pluginLoader.Activate("ClassLibrary2.dll", "ClassLibrary2.Class2");
        //AppDomain adc2 = AppDomain.CreateDomain("adc2");
        //class2 = (Class2)adc2.CreateInstanceAndUnwrap(typeof(Class2).Assembly.FullName, typeof(Class2).FullName);
    }
    public void Increment()
    {
        this.class2.Increment();
    }
    public override string ToString()
    {
        return AppDomain.CurrentDomain.FriendlyName+": "+ this.class2.ToString();
    }
}

程序集:MyLibrary2

public class Class3 : MarshalByRefObject, IPlugin
{
    Class2 class2;

    public Class2 Class2
    {
        get { return class2; }
        set { class2 = value; }
    }
    public Class3()
    {
        PluginLoader.PluginLoader<Class2> pluginLoader = new PluginLoader.PluginLoader<Class2>(new DirectoryInfo(Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location)));
        class2 = pluginLoader.Activate("ClassLibrary2.dll", "ClassLibrary2.Class2");
        //AppDomain adc2 = AppDomain.CreateDomain("adc2");
        //class2 = (Class2)adc2.CreateInstanceAndUnwrap(typeof(Class2).Assembly.FullName, typeof(Class2).FullName);
    }
    public void Increment()
    {
        this.class2.Increment();
    }
    public override string ToString()
    {
        return AppDomain.CurrentDomain.FriendlyName + ": " + this.class2.ToString();
    }
}

程序集:插件接口(interface)

public interface IPlugin
{
    void Increment();
}

程序集:PluginLoader

public class PluginLoader<T> where T : IPlugin
{
    //Here are placed all Fields
    #region Fields
    string path;
    System.AppDomain appDomain;
    #endregion

    //Here are placed all Properties
    #region Properties
    public List<KeyValuePair<String, String>> Plugins
    {
        get { return (List<KeyValuePair<String, String>>)appDomain.GetData("Plugins"); }
    }
    #endregion

    //Here are placed all Constructors
    #region Constructors
    public PluginLoader(DirectoryInfo path)
    {
        this.path = path.FullName;
        if (!path.Exists)
            path.Create();
        AppDomainSetup appDomainSetup = new AppDomainSetup();
        appDomainSetup.AppDomainInitializer = new AppDomainInitializer(GetInterfaceTypes);
        appDomainSetup.AppDomainInitializerArguments = new string[] { this.path };
        appDomain = AppDomain.CreateDomain(typeof(T).Name, null, appDomainSetup);
    }
    #endregion

    #region Methods
    private static void GetInterfaceTypes(string[] args)
    {
        AppDomain appDomain = System.AppDomain.CurrentDomain;
        string[] files = Directory.GetFiles(args[0], "*.dll", SearchOption.AllDirectories);
        List<KeyValuePair<String, String>> infos = new List<KeyValuePair<String, String>>();
        foreach (string file in files)
        {
            try
            {
                Assembly asm = Assembly.LoadFrom(file);
                foreach (Type type in asm.GetTypes())
                {
                    if (typeof(T).IsAssignableFrom(type))
                        infos.Add(new KeyValuePair<string, string>(file, type.FullName));
                }
            }
            catch (Exception ex)
            {
            }
        }
        appDomain.SetData("Plugins", infos);
    }
    public virtual T Activate(String assemblyFile, String type, params object[] args)
    {
        try
        {
            T instance = (T)this.appDomain.CreateInstanceFromAndUnwrap(Path.Combine(this.path, Path.GetFileName(assemblyFile)), type, args);
            return instance;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    #endregion
}

示例2(每个实例计数相同的增量变量):

将所有类放在一个程序集中。

public interface IPlugin
{
    void Increment();
}
[Serializable]
public class Class1 : IPlugin
{
    public Class1() { }
    static int incrementer = 0;
    public void Increment()
    {
        incrementer++;
    }
    public override string ToString()
    {
        return incrementer.ToString();
    }
}
class PluginLoader<T> where T : IPlugin
{
    //Here are placed all Fields
    #region Fields
    string path;
    System.AppDomain appDomain;
    #endregion

    //Here are placed all Properties
    #region Properties
    public List<KeyValuePair<String, String>> Plugins
    {
        get { return (List<KeyValuePair<String, String>>)appDomain.GetData("Plugins"); }
    }
    #endregion

    //Here are placed all Constructors
    #region Constructors
    public PluginLoader(DirectoryInfo path)
    {
        this.path = path.FullName;
        if (!path.Exists)
            path.Create();
        AppDomainSetup appDomainSetup = new AppDomainSetup();
        appDomainSetup.AppDomainInitializer = new AppDomainInitializer(GetInterfaceTypes);
        appDomainSetup.AppDomainInitializerArguments = new string[] { this.path };
        appDomain = AppDomain.CreateDomain(typeof(T).Name, null, appDomainSetup);
    }
    #endregion

    #region Methods
    private static void GetInterfaceTypes(string[] args)
    {
        AppDomain appDomain = System.AppDomain.CurrentDomain;
        string[] files = Directory.GetFiles(args[0], "*.dll", SearchOption.AllDirectories);
        List<KeyValuePair<String, String>> infos = new List<KeyValuePair<String, String>>();
        foreach (string file in files)
        {
            try
            {
                Assembly asm = Assembly.LoadFrom(file);
                foreach (Type type in asm.GetTypes())
                {
                    if (typeof(T).IsAssignableFrom(type))
                        infos.Add(new KeyValuePair<string, string>(file, type.FullName));
                }
            }
            catch (Exception ex)
            {
            }
        }
        appDomain.SetData("Plugins", infos);
    }
    public virtual T Activate(String assemblyFile, String type, params object[] args)
    {
        try
        {
            T instance = (T)this.appDomain.CreateInstanceFromAndUnwrap(Path.Combine(this.path, Path.GetFileName(assemblyFile)), type, args);
            return instance;
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

    #endregion
}
class Program
{
    static void Main(string[] args)
    {
        string file = System.Reflection.Assembly.GetExecutingAssembly().Location;
        string path = Path.GetDirectoryName(file);

        PluginLoader<IPlugin> pluginLoader1 = new PluginLoader<IPlugin>(new DirectoryInfo(path));
        IPlugin cl1 = pluginLoader1.Activate(file, "AppDomainCheck.Class1");
        PluginLoader<IPlugin> pluginLoader2 = new PluginLoader<IPlugin>(new DirectoryInfo(path));
        IPlugin cl3 = pluginLoader1.Activate(file, "AppDomainCheck.Class1");

        cl1.Increment();
        Console.WriteLine(cl1.ToString()); //Output: 1
        cl3.Increment();
        Console.WriteLine(cl3.ToString()); //Output: 2

        Console.ReadKey();
    }
}

Answer 1

静态变量仅限于当前App域。如果您有 N 个不同的应用域，那么静态属性就有 N 个不同的值。

在C# Language Specification 5.0 :

10.5.1 A static field is not part of a specific instance; instead, it is shared amongst all instances of a closed type (§4.4.2). No matter how many instances of a closed class type are created, there is only ever one copy of a static field for the associated application domain.