.Net平台下实例类型无法转换成接口类型?
首先这种情况出现在应用程序启动前的方法里面。
本想通过发射来实现一些功能。谁知道被这个坑了。
碰到这种问题。已经相当无语了。同时也不知道该如何解决。望有能之士帮忙解答
using System; using System.IO; using System.Linq; using System.Reflection; using System.Web; using System.Web.Compilation; using System.Web.Hosting; using Infrastructure; [assembly: PreApplicationStartMethod(typeof(PreApplicationInit), "InitializePlugins")] namespace Infrastructure { public class PreApplicationInit { static PreApplicationInit() { var pluginsPath = HostingEnvironment.MapPath("~/plugins"); var pluginsTempPath = HostingEnvironment.MapPath("~/plugins/temp"); if (pluginsPath == null || pluginsTempPath == null) throw new DirectoryNotFoundException("plugins"); PluginFolder = new DirectoryInfo(pluginsPath); TempPluginFolder = new DirectoryInfo(pluginsTempPath); } /// <summary> /// The source plugin folder from which to copy from /// </summary> /// <remarks> /// This folder can contain sub folders to organize plugin types /// </remarks> private static readonly DirectoryInfo PluginFolder; /// <summary> /// The folder to copy the plugin DLLs to use for running the app /// </summary> private static readonly DirectoryInfo TempPluginFolder; /// <summary> /// Initialize method that registers all plugins /// </summary> public static void InitializePlugins() { var assemblies = PluginFolder.GetFiles("*.dll", SearchOption.AllDirectories) .Select(x => Assembly.LoadFrom(x.FullName)); foreach (var assembly in assemblies) { var type = assembly.GetTypes().FirstOrDefault(t => t.GetInterface(typeof(IModule).Name) != null); if (type == null) continue; //Add the plugin as a reference to the application if (AppDomain.CurrentDomain.GetAssemblies().All(a => a.FullName != assembly.FullName)) { BuildManager.AddReferencedAssembly(assembly); } //Add the modules to the PluginManager to manage them later var module = (IModule)Activator.CreateInstance(type); PluginManager.Current.Modules.Add(module, assembly); } } } }
上面是代码。
如果通过Type.IsAssignableFrom方法来查找接口的实现,根本查不到。
这是目录结构
这是Module的实现
using System; using Infrastructure; namespace NewsPlugin { public class Module:IModule { public string Name { get { return "NewsPlugin"; } set { if (value == null) throw new ArgumentNullException("value"); this.Name = value; } } } }