如何以递归方式将所有引用加载到AppDomain的程序集？

Question

我想加载到一个新的AppDomain一些具有复杂引用树的程序集(MyDll.dll - > Microsoft.Office.Interop.Excel.dll - > Microsoft.Vbe.Interop.dll - > Office.dll - > stdole.dll)

据我所知,当加载程序集时AppDomain,它的引用不会自动加载,我必须手动加载它们.所以当我这样做时:

string dir = @"SomePath"; // different from AppDomain.CurrentDomain.BaseDirectory
string path = System.IO.Path.Combine(dir, "MyDll.dll");

AppDomainSetup setup = AppDomain.CurrentDomain.SetupInformation;
setup.ApplicationBase = dir;
AppDomain domain = AppDomain.CreateDomain("SomeAppDomain", null, setup);

domain.Load(AssemblyName.GetAssemblyName(path));

得到了FileNotFoundException:

无法加载文件或程序集"MyDll,Version = 1.0.0.0,Culture = neutral,PublicKeyToken = null"或其依赖项之一.该系统找不到指定的文件.

我认为关键部分是其依赖性之一.

好的,我之前做过 domain.Load(AssemblyName.GetAssemblyName(path));

foreach (AssemblyName refAsmName in Assembly.ReflectionOnlyLoadFrom(path).GetReferencedAssemblies())
{
    domain.Load(refAsmName);
}

但FileNotFoundException又一次,在另一个(参考)集会上.

如何递归加载所有引用？

在加载根程序集之前是否必须创建引用树？如何在不加载程序集的情况下获取程序集的引用？

Answer 1

您需要CreateInstanceAndUnwrap在代理对象在外部应用程序域中执行之前调用.

 class Program
{
    static void Main(string[] args)
    {
        AppDomainSetup domaininfo = new AppDomainSetup();
        domaininfo.ApplicationBase = System.Environment.CurrentDirectory;
        Evidence adevidence = AppDomain.CurrentDomain.Evidence;
        AppDomain domain = AppDomain.CreateDomain("MyDomain", adevidence, domaininfo);

        Type type = typeof(Proxy);
        var value = (Proxy)domain.CreateInstanceAndUnwrap(
            type.Assembly.FullName,
            type.FullName);

        var assembly = value.GetAssembly(args[0]);
        // AppDomain.Unload(domain);
    }
}

public class Proxy : MarshalByRefObject
{
    public Assembly GetAssembly(string assemblyPath)
    {
        try
        {
            return Assembly.LoadFile(assemblyPath);
        }
        catch (Exception)
        {
            return null;
            // throw new InvalidOperationException(ex);
        }
    }
}

另请注意,如果您使用,LoadFrom您可能会遇到FileNotFound异常,因为程序集解析程序将尝试查找您在GAC或当前应用程序的bin文件夹中加载的程序集.使用LoadFile加载任意组件文件,而不是-但请注意,如果你这样做,你需要自己加载任何依赖关系.

Answer 2

http://support.microsoft.com/kb/837908/en-us

C#版本:

创建一个主持人类并从MarshalByRefObject以下位置继承它:

class ProxyDomain : MarshalByRefObject
{
    public Assembly GetAssembly(string assemblyPath)
    {
        try
        {
            return Assembly.LoadFrom(assemblyPath);
        }
        catch (Exception ex)
        {
            throw new InvalidOperationException(ex.Message);
        }
    }
}

来自客户站点的电话

ProxyDomain pd = new ProxyDomain();
Assembly assembly = pd.GetAssembly(assemblyFilePath);

Answer 3

在新的AppDomain上,尝试设置AssemblyResolve事件处理程序.缺少依赖项时会调用该事件.

Answer 4

一旦将程序集实例传递回调用者域,调用者域将尝试加载它!这就是你得到例外的原因.这发生在你的最后一行代码中:

domain.Load(AssemblyName.GetAssemblyName(path));

因此,无论你想对程序集做什么,都应该在代理类中完成 - 一个继承MarshalByRefObject的类.

记住调用者域和新创建的域应该都可以访问代理类程序集.如果您的问题不是太复杂,请考虑保持ApplicationBase文件夹不变,因此它将与调用者域文件夹相同(新域只会加载它需要的程序集).

在简单的代码中:

public void DoStuffInOtherDomain()
{
    const string assemblyPath = @"[AsmPath]";
    var newDomain = AppDomain.CreateDomain("newDomain");
    var asmLoaderProxy = (ProxyDomain)newDomain.CreateInstanceAndUnwrap(Assembly.GetExecutingAssembly().FullName, typeof(ProxyDomain).FullName);

    asmLoaderProxy.GetAssembly(assemblyPath);
}

class ProxyDomain : MarshalByRefObject
{
    public void GetAssembly(string AssemblyPath)
    {
        try
        {
            Assembly.LoadFrom(AssemblyPath);
            //If you want to do anything further to that assembly, you need to do it here.
        }
        catch (Exception ex)
        {
            throw new InvalidOperationException(ex.Message, ex);
        }
    }
}

如果确实需要从与当前应用程序域文件夹不同的文件夹加载程序集,请使用特定的dll搜索路径文件夹创建新的应用程序域.

例如,上面代码中的app域创建行应替换为:

var dllsSearchPath = @"[dlls search path for new app domain]";
AppDomain newDomain = AppDomain.CreateDomain("newDomain", new Evidence(), dllsSearchPath, "", true);

这样,所有dll都将自动从dllsSearchPath中解析出来.

Answer 5

如果引用的程序集不在GAC中或在CLR的探测路径上,则需要处理AppDomain.AssemblyResolve或AppDomain.ReflectionOnlyAssemblyResolve事件(取决于您正在执行的负载).

AppDomain.AssemblyResolve

AppDomain.ReflectionOnlyAssemblyResolve

Answer 6

关键是 AppDomain 引发的 AssemblyResolve 事件。

[STAThread]
static void Main(string[] args)
{
    fileDialog.ShowDialog();
    string fileName = fileDialog.FileName;
    if (string.IsNullOrEmpty(fileName) == false)
    {
        AppDomain.CurrentDomain.AssemblyResolve += CurrentDomain_AssemblyResolve;
        if (Directory.Exists(@"c:\Provisioning\") == false)
            Directory.CreateDirectory(@"c:\Provisioning\");

        assemblyDirectory = Path.GetDirectoryName(fileName);
        Assembly loadedAssembly = Assembly.LoadFile(fileName);

        List<Type> assemblyTypes = loadedAssembly.GetTypes().ToList<Type>();

        foreach (var type in assemblyTypes)
        {
            if (type.IsInterface == false)
            {
                StreamWriter jsonFile = File.CreateText(string.Format(@"c:\Provisioning\{0}.json", type.Name));
                JavaScriptSerializer serializer = new JavaScriptSerializer();
                jsonFile.WriteLine(serializer.Serialize(Activator.CreateInstance(type)));
                jsonFile.Close();
            }
        }
    }
}

static Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
    string[] tokens = args.Name.Split(",".ToCharArray());
    System.Diagnostics.Debug.WriteLine("Resolving : " + args.Name);
    return Assembly.LoadFile(Path.Combine(new string[]{assemblyDirectory,tokens[0]+ ".dll"}));
}

Answer 7

我花了一段时间才了解@ user1996230的答案，因此我决定提供一个更明确的示例。在下面的示例中，我为另一个AppDomain中加载的对象创建代理，并从另一个域对该对象调用方法。

class ProxyObject : MarshalByRefObject
{
    private Type _type;
    private Object _object;

    public void InstantiateObject(string AssemblyPath, string typeName, object[] args)
    {
        assembly = Assembly.LoadFrom(AppDomain.CurrentDomain.BaseDirectory + AssemblyPath); //LoadFrom loads dependent DLLs (assuming they are in the app domain's base directory
        _type = assembly.GetType(typeName);
        _object = Activator.CreateInstance(_type, args); ;
    }

    public void InvokeMethod(string methodName, object[] args)
    {
        var methodinfo = _type.GetMethod(methodName);
        methodinfo.Invoke(_object, args);
    }
}

static void Main(string[] args)
{
    AppDomainSetup setup = new AppDomainSetup();
    setup.ApplicationBase = @"SomePathWithDLLs";
    AppDomain domain = AppDomain.CreateDomain("MyDomain", null, setup);
    ProxyObject proxyObject = (ProxyObject)domain.CreateInstanceFromAndUnwrap(typeof(ProxyObject).Assembly.Location,"ProxyObject");
    proxyObject.InstantiateObject("SomeDLL","SomeType", new object[] { "someArgs});
    proxyObject.InvokeMethod("foo",new object[] { "bar"});
}