无法从动态生成的程序集访问CodeBase

Question

我正在尝试在.Net中动态创建一个程序集。但是，我似乎不知道如何让CodeBase属性返回值。下面是一个例子：

var assemblyName = new AssemblyName
                        {
                            Name = "Whatever",
                            CodeBase = Directory.GetCurrentDirectory()
                        };
var assemblyBuilder = AppDomain.CurrentDomain
    .DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.RunAndSave);
var moduleBuilder = assemblyBuilder.DefineDynamicModule("WhateverModule", "Whatever.dll");
var typeBuilder = moduleBuilder.DefineType("WhateverType", TypeAttributes.Public);
var type = typeBuilder.CreateType();
assemblyBuilder.Save("Whatever.dll");
var codeBase = type.Assembly.CodeBase; // throws the below exception

System.NotSupportedException was unhandled
  Message=The invoked member is not supported in a dynamic assembly.
  Source=mscorlib
  StackTrace:
       at System.Reflection.Emit.InternalAssemblyBuilder.get_CodeBase()
       at Stupid.Program.Main(String[] args) in C:\Users\Walking Disaster\Documents\Visual Studio 10\Projects\Lingual.Proxy\Stupid\Program.cs:line 25
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()

有没有人看到我做错了什么？

说明:我正在尝试用一个在运行时生成测试方法的插件来扩展NUnit。它通过接受一组Action委托来实现这一点。不幸的是，反射已经深入到框架中了，所以我必须使用每个Action委托的方法来发出类。当我只使用NUnitTestMethod类时，它工作得很好，但是当我使用NUnitTestFixture时，它失败了，因为它试图从程序集中读取CodeBase。我不想创建一个物理程序集，但这个项目已经是一个接一个的妥协。

Answer 1

我认为异常的原因是CodeBase在动态程序集上没有意义。来自MSDN：

最初指定的程序集的位置

如果你要重新加载程序集，它不会抛出异常：

var assemblyName = new AssemblyName
                       {
                           Name = "Whatever",
                           CodeBase = Directory.GetCurrentDirectory()
                       };
var assemblyBuilder = AppDomain.CurrentDomain
    .DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.RunAndSave);
var moduleBuilder = assemblyBuilder.DefineDynamicModule(
    "WhateverModule", "Whatever.dll");
var typeBuilder = 
                 moduleBuilder.DefineType("WhateverType", TypeAttributes.Public);
var type = typeBuilder.CreateType();
assemblyBuilder.Save("Whatever.dll");

var assembly = Assembly.LoadFrom("Whatever.dll");
var codeBase = assembly.CodeBase; // this won't throw exception

Answer 2

程序集的Location是否有效？您可以派生NUnit并使用它，而不是给定您的参考损坏:P

我花了几个小时听NUnit的“可扩展性”的故事，我无法想象会选择它而不是xUnit.net --但我猜最终的决定者将是你有多少测试……