无法从动态生成的程序集访问CodeBase

时间:2010-04-10 20:46:41

标签: c# .net reflection reflection.emit

我正在尝试在.Net中动态创建程序集。但是,我似乎无法弄清楚如何让CodeBase属性返回一个值。这是一个例子:

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()

谁能看到我做错了什么?

说明:我正在尝试使用在运行时生成测试方法的插件来扩展NUnit。它通过获取一系列Action代理来实现此目的。不幸的是,Reflection深入到框架中,所以我不得不为每个Action委托发出一个带有方法的类。当我只使用NUnitTestMethod类时,这很好用,但是当我使用NUnitTestFixture时,它会失败,因为它试图从程序集中读取CodeBase。我不想创建一个物理组件,但这个项目是一个接一个的妥协。

2 个答案:

答案 0 :(得分:3)

我认为异常原因是CodeBase在动态组装上毫无意义。来自MSDN:

  

最初指定的程序集的位置

如果您要重新加载程序集,它将不会抛出异常:

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

答案 1 :(得分:1)

大会的Location有效吗?您可以分叉NUnit并使用它来代替您提到损坏:P

我花了几个小时接受NUnit的'可扩展性'故事,并且无法想象它会在xUnit.net上选择它 - 但我想这决定了你会有多少测试......