加载DLL到一个单独的AppDomain已知唯一通用接口 [英] Loading DLLs into a separate AppDomain with known only common interface

问题描述

我需要在另一个域中加载.DLL（插件）。在主应用程序，我不知道插件类型的东西，只是他们实现共同的接口ICommonInterface用一些方法。所以这个代码将不会帮助，因为我不能创建接口类型的实例。

I need to load .dll(plugins) in another domain. In main app I don't know anything about plugins types, only that they implement common interface ICommonInterface with some methods. So this code wouldn't help, because I can't create an instance with interface type.

AppDomain domain = AppDomain.CreateDomain("New domain name");
//Do other things to the domain like set the security policy

string pathToDll = @"C:\myDll.dll"; //Full path to dll you want to load
Type t = typeof(TypeIWantToLoad);
TypeIWantToLoad myObject = (TypeIWantToLoad)domain.CreateInstanceFromAndUnwrap(pathToDll, t.FullName);

我的问题是如何在新的域加载程序集，并得到举例来说，如果我知道的唯一接口。名称，它实现键入我想创建一个

My question is how I can load assembly in new domain and get the instance, if I know only interface name which implements type I want to create.

更新：
这里是我的代码：
MainLib.dll

UPDATE: Here is my code: MainLib.dll

namespace MainLib
{
public interface ICommonInterface
{
    void ShowDllName();
}
}

PluginWithOutException.dll

PluginWithOutException.dll

namespace PluginWithOutException
{
public class WithOutException : MarshalByRefObject, ICommonInterface
{
    public void ShowDllName()
    {
        Console.WriteLine("PluginWithOutException");
    }
}
}

PluginWithException.dll

PluginWithException.dll

namespace PluginWithException
{
public class WithException : MarshalByRefObject, ICommonInterface
{
    public void ShowDllName()
    {
        Console.WriteLine("WithException");
        throw new NotImplementedException();
    }
}
}

和主要应用程序：

        static void Main(string[] args)
    {
        string path = @"E:\Plugins\";
        string[] assemblies = Directory.GetFiles(path);

        List<string> plugins = SearchPlugins(assemblies);

        foreach (string item in plugins)
        {
            CreateDomainAndLoadAssebly(item);
        }

        Console.ReadKey();
    }

    public static List<string> SearchPlugins(string[] names)
    {
        AppDomain domain = AppDomain.CreateDomain("tmpDomain");
        domain.Load(Assembly.LoadFrom(@"E:\Plugins\MainLib.dll").FullName);
        List<string> plugins = new List<string>();

        foreach (string asm in names)
        {
            Assembly loadedAssembly = domain.Load(Assembly.LoadFrom(asm).FullName);

            var theClassTypes = from t in loadedAssembly.GetTypes()
                                where t.IsClass &&
                                      (t.GetInterface("ICommonInterface") != null)
                                select t;
            if (theClassTypes.Count() > 0)
            {
                plugins.Add(asm);
            }
        }
        AppDomain.Unload(domain);
        return plugins;
    }

插件和应用程序主要有参考MainLib.dll。其主要目的是不加载在默认域组件，但它们加载到其他领域，所以当我不需要他们，我只是卸载（）域，从申请卸载所有插件。

Plugins and main app have reference to MainLib.dll. The main aim is to not to load assemblies in default domain, but load them to another domains, so when I don't need them, I just Unload() domain and unload all plugins from application.

对于现在的例外是 FileNotFoundException异常，无法加载文件或程序'PluginWithException，版本= 1.0.0.0，文化=中立，公钥=空或它的一个依赖。该系统找不到指定的文件）的字符串大会loadedAssembly = domain.Load（Assembly.LoadFrom（ASM）.FullName）; （我试图加载一个名为PluginWithException插件），我已经删除插件的所有依赖，exept系统，我在这个领域加载System.dll中（它加载正确的，它是在域），但仍然无法加载插件到域。 。此外，我选中，PluginWithException有2个依赖 - mscorlib程序和MainLib，他们都装到这个域的

For now the exception is FileNotFoundException, Could not load file or assembly 'PluginWithException, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.) on string Assembly loadedAssembly = domain.Load(Assembly.LoadFrom(asm).FullName);(I trying to load plugin with name PluginWithException), I've delete all the dependencies in plugins, exept System, I loaded System.dll in this domain(it loaded correct and it is in domain), but still cant load plugins into domain. Also I checked, that PluginWithException has 2 dependencies - mscorlib and MainLib, and all of them loaded to this domain.

更新：此处我问更多的细节这个问题。

UPDATE: Here I asked this question with more details.

推荐答案

我不知道这是否是你需要什么，我会尽力帮助你们。
这是我该怎么办加载插件程序集。我使用一个辅助类来管理新的AppDomain和该程序集类的实例。这是辅助类：

I'm not sure if it's what you need, i'd try to help you with this. This is how I do to load plugin assemblies. I use a helper class to manage new AppDomain and the instance of the class on that assembly. This is the helper class:

[Serializable, ClassInterface(ClassInterfaceType.AutoDual)]
class helperDomain<T>: MarshalByRefObject where T: class
{
    #region private
    private AppDomain _app_domain;
    private AppDomainSetup _app_domain_info;

    private string _assembly_class_name;
    private string _assembly_file;
    private string _assembly_file_name;
    private T _inner_class;
    private bool _load_ok;
    private string _loading_errors;
    private string _path;
    #endregion

    #region .ctor
    public helperDomain(string AssemblyFile, 
       string configFile = null, string domainName)
    {
        this._load_ok = false;
        try
        {
            this._assembly_file = AssemblyFile; //full path to assembly
            this._assembly_file_name = System.IO.Path.GetFileName(this._assembly_file); //assmbly file name
            this._path = System.IO.Path.GetDirectoryName(this._assembly_file); //get root directory from assembly path 
            this._assembly_class_name = typeof(T).ToString(); //the class name to instantiate in the domain from the assembly
            //start to configure domain
            this._app_domain_info = new AppDomainSetup();
            this._app_domain_info.ApplicationBase = this._path;
            this._app_domain_info.PrivateBinPath = this._path;
            this._app_domain_info.PrivateBinPathProbe = this._path;
            if (!string.IsNullOrEmpty(configFile))
            {
                this._app_domain_info.ConfigurationFile = configFile;
            }
            //lets create the domain
            this._app_domain = AppDomain.CreateDomain(domainName, null, this._app_domain_info);
            //instantiate the class
            this._inner_class = (T) this._app_domain.CreateInstanceFromAndUnwrap(this._assembly_file, this._assembly_class_name);
            this._load_ok = true;
        }
        catch (Exception exception)
        {
            //There was a problema setting up the new appDomain
            this._load_ok = false;
            this._loading_errors = exception.ToString();
        }
    }
    #endregion


    #region public properties
    public string AssemblyFile
    {
        get
        {
            return _assembly_file;
        }
    }

    public string AssemblyFileName
    {
        get
        {
            return _assembly_file_name;
        }
    }

    public AppDomain AtomicAppDomain
    {
        get
        {
            return _app_domain;
        }
    }

    public T InstancedObject
    {
        get
        {
            return _inner_class;
        }
    }

    public string LoadingErrors
    {
        get
        {
            return _loading_errors;
        }
    }

    public bool LoadOK
    {
        get
        {
            return _load_ok;
        }
    }

    public string Path
    {
        get
        {
            return _path;
        }
    }
    #endregion
}

然后加载插件（每一个diferent文件夹）。

and then load plugins (each in a diferent folder).

foreach(string pluginassemblypath in pluginspaths)
{ 
    //Each pluginassemblypath (as it says..) is the full path to the assembly
    helperDomain<IPluginClass> isoDomain = 
        helperDomain<IPluginClass>(pluginassemblypath, 
             pluginassemblypath + ".config", 
             System.IO.Path.GetFileName(pluginassemblypath) + ".domain");
    if (isoDomain.LoadOK)
    {
       //We can access instance of the class (.InstancedObject)
       Console.WriteLine("Plugin loaded..." + isoDomain.InstancedObject.GetType().Name);
    }
    else
    {
       //Something happened...
       Console.WriteLine("There was en error loading plugin " + 
            pluginassemblypath + " - " + helperDomain.LoadingErrors);
    }
}

希望它会帮助你...

Hope it will helps you...

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