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在运行时编译代码,加载到当前AppDomain中,但type.getType看不到它

compiler-construction reflection asp.net .net c#

Richard Friend · 技术社区 · 15 年前

我在运行时编译了一些代码,然后将程序集加载到当前的AppDomain中,但是当我尝试执行type.getType时,它找不到类型…

下面是我如何编译代码…

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。很好,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);



....

2 回复 | 直到 15 年前

Richard Friend 15 年前

发现 this 一段很好的代码,可以确保无论如何加载程序集,它始终可以从type.gettype获得。

我的类用于将代码编译到当前AppDomain中,现在看起来如下:

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];
    }


}

-1

Achim 15 年前

您应该多读一些关于程序集加载、类型解析…我完全不知道您的代码为什么工作,但我想您有以下问题:

编译程序集,然后调用appdomain.currentdomain.load加载程序集。但不返回刚加载的程序集。从编译结果返回程序集。现在,您有了同一程序集的两个实例,并且该程序集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!