运行时编译代码，加载到当前应用程序域，但Type.GetType看不到它

Question

我在运行时编译一些代码，然后将程序集加载到当前的应用程序域中，但是当我尝试执行 Type.GetType 时，它找不到类型...

这是我编译代码的方法...

public static Assembly CompileCode(string code)
    {
        Microsoft.CSharp.CSharpCodeProvider provider = new CSharpCodeProvider();
        ICodeCompiler compiler = provider.CreateCompiler();
        CompilerParameters compilerparams = new CompilerParameters();
        compilerparams.GenerateExecutable = false;
        compilerparams.GenerateInMemory = false;

        foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
        {
            try
            {
                string location = assembly.Location;
                if (!String.IsNullOrEmpty(location))
                {
                    compilerparams.ReferencedAssemblies.Add(location);
                }
            }
            catch (NotSupportedException)
            {
                // this happens for dynamic assemblies, so just ignore it. 
            }
        } 
        CompilerResults results =
           compiler.CompileAssemblyFromSource(compilerparams, code);
        if (results.Errors.HasErrors)
        {
            StringBuilder errors = new StringBuilder("Compiler Errors :\r\n");
            foreach (CompilerError error in results.Errors)
            {
                errors.AppendFormat("Line {0},{1}\t: {2}\n",
                       error.Line, error.Column, error.ErrorText);
            }
            throw new Exception(errors.ToString());
        }
        else
        {
            AppDomain.CurrentDomain.Load(results.CompiledAssembly.GetName());
            return results.CompiledAssembly;
        }
    }

从编译的程序集中获取类型后，此位失败了，它似乎无法使用 Type.GetType 找到它....

Assembly assem = RuntimeCodeCompiler.CompileCode(code);
string typeName = 
      String.Format("Peverel.AppFramework.Web.GenCode.ObjectDataSourceProxy_{0}",
        safeTypeName);



Type t = assem.GetType(typeName); //This works just fine..
Type doesntWork = Type.GetType(t.AssemblyQualifiedName);
Type doesntWork2 = Type.GetType(t.Name);



....

Answer 1

发现this一段不错的代码，可以确保无论您如何加载程序集，它始终可以从 Type.GetType 获得。

我的用于将代码编译到当前应用程序域的类现在看起来像：

public static class RuntimeCodeCompiler
{
    private static volatile Dictionary<string, Assembly> cache = new Dictionary<string, Assembly>();
    private static object syncRoot = new object();
    static Dictionary<string, Assembly> assemblies = new Dictionary<string, Assembly>();
    static RuntimeCodeCompiler()
    {
        AppDomain.CurrentDomain.AssemblyLoad += (sender, e) =>
        {
            assemblies[e.LoadedAssembly.FullName] = e.LoadedAssembly;
        };
        AppDomain.CurrentDomain.AssemblyResolve += (sender, e) =>
        {
            Assembly assembly = null;
            assemblies.TryGetValue(e.Name, out assembly);
            return assembly;
        };

    }


    public static Assembly CompileCode(string code)
    {

        Microsoft.CSharp.CSharpCodeProvider provider = new CSharpCodeProvider();
        ICodeCompiler compiler = provider.CreateCompiler();
        CompilerParameters compilerparams = new CompilerParameters();
        compilerparams.GenerateExecutable = false;
        compilerparams.GenerateInMemory = false;



        foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
        {
            try
            {
                string location = assembly.Location;
                if (!String.IsNullOrEmpty(location))
                {
                    compilerparams.ReferencedAssemblies.Add(location);
                }
            }
            catch (NotSupportedException)
            {
                // this happens for dynamic assemblies, so just ignore it. 
            }
        } 


        CompilerResults results =
           compiler.CompileAssemblyFromSource(compilerparams, code);
        if (results.Errors.HasErrors)
        {
            StringBuilder errors = new StringBuilder("Compiler Errors :\r\n");
            foreach (CompilerError error in results.Errors)
            {
                errors.AppendFormat("Line {0},{1}\t: {2}\n",
                       error.Line, error.Column, error.ErrorText);
            }
            throw new Exception(errors.ToString());
        }
        else
        {

            AppDomain.CurrentDomain.Load(results.CompiledAssembly.GetName());
            return results.CompiledAssembly;
        }

    }

    public static Assembly CompileCodeOrGetFromCache(string code,  string key)
    {
        bool exists = cache.ContainsKey(key);

        if (!exists)
        {

            lock (syncRoot)
            {
                exists = cache.ContainsKey(key);

                if (!exists)
                {
                    cache.Add(key, CompileCode(code));
                }
            }
        }

        return cache[key];
    }


}

Answer 2

您应该阅读更多有关程序集加载、类型解析等内容，...我根本不知道您的代码为何有效，但我猜您遇到以下问题：

编译程序集，然后调用 AppDomain.CurrentDomain.Load 加载程序集。但您不会返回刚刚加载的程序集。您从编译结果中返回程序集。现在，您有同一程序集的两个实例，并且该程序集中的每种类型都有两次。这些对具有相同的名称，但它们不是相同的类型！