简述ASP.NET MVC引擎开发插件系统的图文解释与代码实例

usingSystem;

usingSystem.Collections.Generic;

usingSystem.IO;

usingSystem.Linq;

usingSystem.Reflection;

usingSystem.Text;

usingSystem.Threading.Tasks;

usingSystem.Web;

usingSystem.Web.Compilation;

usingSystem.Web.Hosting;

[assembly: PreApplicationStartMethod(typeof(Plugins.Core.PreApplicationInit),"Initialize")]

namespacePlugins.Core

{

 publicclassPreApplicationInit

 {

  staticPreApplicationInit()

  {

   PluginFolder =newDirectoryInfo(HostingEnvironment.MapPath("~/plugins"));

   ShadowCopyFolder =newDirectoryInfo(HostingEnvironment.MapPath("~/plugins/temp"));

  }

  ///

  /// 插件所在目录信息

  ///

  privatestaticreadonlyDirectoryInfo PluginFolder;

  ///

  /// 程序应行时指定的dll目录

  ///

  privatestaticreadonlyDirectoryInfo ShadowCopyFolder;

  publicstaticvoidInitialize()

  {

   Directory.CreateDirectory(ShadowCopyFolder.FullName);

   //清空插件dll运行目录中的文件

   foreach(var finShadowCopyFolder.GetFiles("*.dll", SearchOption.AllDirectories))

   {

    f.Delete();

   }

   foreach(var pluginPluginFolder.GetFiles("*.dll", SearchOption.AllDirectories).Where(i=>i.Directory.Parent.Name=="plugins"))

   {

    File.Copy(plug.FullName, Path.Combine(ShadowCopyFolder.FullName, plug.Name),true);

   }

   foreach(var ain

    ShadowCopyFolder

    .GetFiles("*.dll", SearchOption.AllDirectories)

    .Select(x => AssemblyName.GetAssemblyName(x.FullName))

    .Select(x => Assembly.Load(x.FullName)))

   {

    BuildManager.AddReferencedAssembly(a);

   }

  }

 }

}

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Linq;

usingSystem.Threading.Tasks;

usingSystem.Web;

usingSystem.Web.Mvc;

usingSystem.Web.WebPages.Razor;

namespacePlugins.Web

{

 publicclassCustomerViewEngine : RazorViewEngine

 {

  ///

  /// 定义视图页所在地址。

  ///

  privatestring[] _viewLocationFormats =new[]

  {

   "~/Views/Parts/{0}.cshtml",

   "~/Plugins/{pluginFolder}/Views/{1}/{0}.cshtml",

   "~/Plugins/{pluginFolder}/Views/Shared/{0}.cshtml",

   "~/Views/{1}/{0}.cshtml",

   "~/Views/Shared/{0}.cshtml",

  };

  publicoverrideViewEngineResult FindView(ControllerContext controllerContext,stringviewName,stringmasterName,booluseCache)

  {

   stringns = controllerContext.Controller.GetType().Namespace;

   stringcontroller = controllerContext.Controller.GetType().Name.Replace("Controller","");

   //说明是插件中的控制器，View目录需要单独处理

   if(ns.ToLower().Contains("plugins"))

   {

    var pluginsFolder = ns.ToLower().Replace(".controllers","");

    ViewLocationFormats = ReplacePlaceholder(pluginsFolder);

   }

   returnbase.FindView(controllerContext, viewName, masterName, useCache);

  }

  ///

  /// 替换pluginFolder占位符

  ///

  ///

  privatestring[] ReplacePlaceholder(stringfolderName)

  {

   string[] tempArray =newstring[_viewLocationFormats.Length];

   if(_viewLocationFormats !=null)

   {

    for(inti = 0; i < _viewLocationFormats.Length; i++)

    {

     tempArray[i] = _viewLocationFormats[i].Replace("{pluginFolder}", folderName);

    }

   }

   returntempArray;

  }

 }

}