AppDomain.Load() 因 FileNotFoundException 失败 [英] AppDomain.Load() fails with FileNotFoundException

问题描述

我正在尝试将我的插件 dll 加载到单独的 AppDomain，但 Load() 方法因 FileNotFoundException 而失败.此外，似乎设置 AppDomainSetup 的 PrivateBinPath 属性没有效果，因为在日志中我看到Initial PrivatePath = NULL".所有插件都有强名称.通常每个插件都存储在[应用程序启动路径]\postplugins\[plugindir].如果我将 plugins 子目录放在 [Application startp path] 目录下，则一切正常.我也尝试过手动更改 AppBase 属性，但它没有更改.
代码如下:

I'm trying to load my plugin dll into separate AppDomain, but Load() method fails with FileNotFoundException. Moreover, it seems like setting PrivateBinPath property of AppDomainSetup has no effect, because in log I see "Initial PrivatePath = NULL". All plugin have strong name. Normally each plugin is stored in [Application startp path]\postplugins\[plugindir]. If I put plugins subdirectories under [Application startp path] directory, everything works. I also have tried to change AppBase property manually but it does not change.
Here is the code:

public void LoadPostPlugins(IPluginsHost host, string pluginsDir)
    {
        _Host = host;
        var privatePath = "";
        var paths = new List<string>();
        //build PrivateBinPath
        var dirs = new DirectoryInfo(pluginsDir).GetDirectories();
        foreach (var d in dirs)
        {
            privatePath += d.FullName;
            privatePath += ";";
        }
        if (privatePath.Length > 1) privatePath = privatePath.Substring(0, privatePath.Length - 1);
        //create new domain
        var appDomainSetup = new AppDomainSetup { PrivateBinPath = privatePath };
        Evidence evidence = AppDomain.CurrentDomain.Evidence;
        var sandbox = AppDomain.CreateDomain("sandbox_" + Guid.NewGuid(), evidence, appDomainSetup);
        try
        {
            foreach (var d in dirs)
            {
                var files = d.GetFiles("*.dll");
                foreach (var f in files)
                {
                    try
                    {
                        //try to load dll - here I get FileNotFoundException
                        var ass = sandbox.Load(AssemblyName.GetAssemblyName(f.FullName));
                        var f1 = f;
                        paths.AddRange(from type in ass.GetTypes()
                                       select type.GetInterface("PluginsCore.IPostPlugin")
                                       into iface
                                       where iface != null
                                       select f1.FullName);
                    }
                    catch (FileNotFoundException ex)
                    {
                        Debug.WriteLine(ex);
                    }
                }
            }
        }
        finally
        {
            AppDomain.Unload(sandbox);
        }
        foreach (var plugin in from p in paths
                               select Assembly.LoadFrom(p)
                                   into ass
                                   select
                                       ass.GetTypes().FirstOrDefault(t => t.GetInterface("PluginsCore.IPostPlugin") != null)
                                       into type
                                       where type != null
                                       select (IPostPlugin)Activator.CreateInstance(type))
        {
            plugin.Init(host);
            plugin.GotPostsPartial += plugin_GotPostsPartial;
            plugin.GotPostsFull += plugin_GotPostsFull;
            plugin.PostPerformed += plugin_PostPerformed;
            _PostPlugins.Add(plugin);
        }
    }

这是日志:

'FBTest.vshost.exe' (Managed (v4.0.30319)): Loaded 'D:\VS2010Projects\PNotes - NET\pnfacebook\FBTest\bin\Debug\postplugins\pnfacebook\pnfacebook.dll', Symbols loaded.
A first chance exception of type 'System.IO.FileNotFoundException' occurred in FBTest.exe
System.IO.FileNotFoundException: Could not load file or assembly 'pnfacebook, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9e2a2192d22aadc7' or one of its dependencies. The system cannot find the file specified.
File name: 'pnfacebook, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9e2a2192d22aadc7'
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks)
   at System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean forIntrospection)
   at System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)
   at System.Reflection.Assembly.Load(String assemblyString)
   at System.UnitySerializationHolder.GetRealObject(StreamingContext context)

   at System.AppDomain.Load(AssemblyName assemblyRef)
   at PNotes.NET.PNPlugins.LoadPostPlugins(IPluginsHost host, String pluginsDir) in D:\VS2010Projects\PNotes - NET\pnfacebook\FBTest\PNPlugins.cs:line 71


=== Pre-bind state information ===
LOG: User = ANDREYHP\Andrey
LOG: DisplayName = pnfacebook, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9e2a2192d22aadc7
 (Fully-specified)
LOG: Appbase = file:///D:/VS2010Projects/PNotes - NET/pnfacebook/FBTest/bin/Debug/
LOG: Initial PrivatePath = NULL
Calling assembly : (Unknown).
===
LOG: This bind starts in default load context.
LOG: No application configuration file found.
LOG: Using host configuration file: 
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
LOG: Post-policy reference: pnfacebook, Version=1.0.0.0, Culture=neutral, PublicKeyToken=9e2a2192d22aadc7
LOG: Attempting download of new URL file:///D:/VS2010Projects/PNotes - NET/pnfacebook/FBTest/bin/Debug/pnfacebook.DLL.
LOG: Attempting download of new URL file:///D:/VS2010Projects/PNotes - NET/pnfacebook/FBTest/bin/Debug/pnfacebook/pnfacebook.DLL.
LOG: Attempting download of new URL file:///D:/VS2010Projects/PNotes - NET/pnfacebook/FBTest/bin/Debug/pnfacebook.EXE.
LOG: Attempting download of new URL file:///D:/VS2010Projects/PNotes - NET/pnfacebook/FBTest/bin/Debug/pnfacebook/pnfacebook.EXE.

推荐答案

当您以这种方式将程序集加载到 AppDomain 中时，当前 AppDomain 的 PrivateBinPath 将用于查找程序集.

when you load an assembly into the AppDomain in that way, it is the current AppDomain's PrivateBinPath that is used to find the assembly.

例如，当我将以下内容添加到我的 App.config 时，它运行良好:

For your example, when I added the following to my App.config it ran fine:

<runtime>
  <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
    <probing privatePath="[PATH_TO_PLUGIN]"/>
  </assemblyBinding>
</runtime>

不过这对你来说不是很有用.

This is not very useful to you though.

我所做的是创建一个包含 IPostPlugin 和 IPluginsHost 接口的新程序集，以及一个名为 Loader 的类，如下所示:

What I did instead was to create a new assembly that contained the IPostPlugin and IPluginsHost interfaces, and also a class called Loader that looked like this:

public class Loader : MarshalByRefObject
{
    public IPostPlugin[] LoadPlugins(string assemblyName)
    {
        var assemb = Assembly.Load(assemblyName);

        var types = from type in assemb.GetTypes()
                where typeof(IPostPlugin).IsAssignableFrom(type)
                select type;

        var instances = types.Select(
            v => (IPostPlugin)Activator.CreateInstance(v)).ToArray();

        return instances;
    }
}

我将这个新程序集保存在应用程序根目录中，它不需要存在于插件目录中(它可以但不会被使用，因为将首先搜索应用程序根目录).

I keep that new assembly in the application root, and it doesn't need to exist in the plugin directories (it can but won't be used as the application root will be searched first).

然后在主 AppDomain 中，我改为这样做:

Then in the main AppDomain I did this instead:

sandbox.Load(typeof(Loader).Assembly.FullName);

Loader loader = (Loader)Activator.CreateInstance(
    sandbox,
    typeof(Loader).Assembly.FullName,
    typeof(Loader).FullName,
    false,
    BindingFlags.Public | BindingFlags.Instance,
    null,
    null,
    null,
    null).Unwrap();

var plugins = loader.LoadPlugins(AssemblyName.GetAssemblyName(f.FullName).FullName);

foreach (var p in plugins)
{
    p.Init(this);
}

_PostPlugins.AddRange(plugins);

所以我创建了一个已知 Loader 类型的实例，然后获取它以从插件 AppDomain 内创建插件实例.这样 PrivateBinPath 就会按照您的意愿使用.

So I create an instance of the known Loader type, and then get that to create the plugin instances from within the plug-in AppDomain. That way the PrivateBinPaths are used as you want them to be.

另一件事，私有 bin 路径可以是相对的，因此您可以添加 pluginsDir + Path.DirectorySeparatorChar + d.Name 来保持最终路径列表很短.不过这只是我个人的喜好！希望这会有所帮助.

One other thing, the private bin paths can be relative so rather than adding d.FullName you could add pluginsDir + Path.DirectorySeparatorChar + d.Name to keep the final path list short. That's just my personal preference though! Hope this helps.

这篇关于AppDomain.Load() 因 FileNotFoundException 失败的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！