c# - 从应用程序域卸载程序集

Question

代码应该创建域，将 dll 加载到域中，卸载 dll

但是在新域上调用 unload 后 dll 仍然存在吗？

 private void Method1()
 {
        //create new domain
        AppDomain domain = AppDomain.CreateDomain("MyDomain");
        AppDomain.CurrentDomain.AssemblyResolve += CurrentDomain_AssemblyResolve;

        //load dll into new domain
        AssemblyName assemblyName = new AssemblyName();
        assemblyName.CodeBase = "c:\\mycode.dll";
        Assembly assembly = domain.Load(assemblyName);         

        //do work with dll
        //...

        //unload dll
        AppDomain.Unload(domain); 

        //still showing dll below ?????
        Assembly[] aAssemblies = AppDomain.CurrentDomain.GetAssemblies(); 
}
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[] { "c:\\", tokens[0] + ".dll" }));
}

有什么想法为什么 dll 没有卸载吗？

编辑(让它按如下方式工作)

正如 Jean 指出的那样，domain.Load 是问题所在，在同一项目中使用带有代理类的 CreateInstanceAndUnwrap 是可行的。)

而不是

    //load dll into new domain *** this does not work
    AssemblyName assemblyName = new AssemblyName();
    assemblyName.CodeBase = "c:\\mycode.dll";
    Assembly assembly = domain.Load(assemblyName); 

到此

    // loads proxy class into new domain               
    Type myType = typeof(Proxy);
    var value = (Proxy)domain.CreateInstanceAndUnwrap(
             myType.Assembly.FullName,
             myType.FullName);   
    //DoWork:- loads assembly into domain
    // calls methods, returns result                 
    Int32 result = value.DoWork(pathToDll);
    //Unload domain and thus assembly
    AppDomain.Unload(domain);
    //Assembly not present in current domain
    Assembly[] list = AppDomain.CurrentDomain.GetAssemblies();

将以下类添加到当前命名空间

    public class Proxy : MarshalByRefObject
    {
        public Int32 DoWork(string assemblyPath)
        {
            try
            {
            Assembly assembly = Assembly.LoadFile(assemblyPath);
            Int32 response = 0;

            Type tObject = assembly.GetType("namespace.class");
            MethodInfo Method = tObject.GetMethod("method");

            Type myType = typeof(Proxy);
            object myInstance = Activator.CreateInstance(myType);                
            response =  (Int32) Method.Invoke(myInstance, null);

            return response;
            }
            catch (Exception ex)
            {
            throw ex;
            }
        }
    }

Answer 1

根据经验，一旦有了 Assembly 实例，就意味着相关程序集已加载到当前域中。

这意味着，当您调用AppDomain.Load时方法，您可以在当前域和新域中加载程序集。 (正如您在 MSDN 上对该方法的注释中看到的那样，“此方法只能用于将程序集加载到当前应用程序域中。”)

编辑:之前发布的“解决方案”已被删除，因为它并没有真正解决问题。作者将可行的解决方案编辑到问题中。