<runtime>
 <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <probing privatePath="Plugins/temp/" />
 </assemblyBinding>
 </runtime>

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Web.Compilation;
using System.Web.Hosting;
[assembly: PreApplicationStartMethod(typeof(Plugins.Core.PreApplicationInit), "Initialize")]
namespace Plugins.Core
{
 public class PreApplicationInit
 {

  static PreApplicationInit()
  {
   PluginFolder = new DirectoryInfo(HostingEnvironment.MapPath("~/plugins"));
   ShadowCopyFolder = new DirectoryInfo(HostingEnvironment.MapPath("~/plugins/temp"));
  }

  /// <summary>
  /// 插件所在目录信息
  /// </summary>
  private static readonly DirectoryInfo PluginFolder;

  /// <summary>
  /// 程序应行时指定的dll目录
  /// </summary>
  private static readonly DirectoryInfo ShadowCopyFolder;

  public static void Initialize()
  {
   Directory.CreateDirectory(ShadowCopyFolder.FullName);
   //清空插件dll运行目录中的文件
   foreach (var f in ShadowCopyFolder.GetFiles("*.dll", SearchOption.AllDirectories))
   {
    f.Delete();
   }
   foreach (var plug in PluginFolder.GetFiles("*.dll", SearchOption.AllDirectories).Where(i=>i.Directory.Parent.Name== "plugins"))
   {
    File.Copy(plug.FullName, Path.Combine(ShadowCopyFolder.FullName, plug.Name), true);
   }
   foreach (var a in
    ShadowCopyFolder
    .GetFiles("*.dll", SearchOption.AllDirectories)
    .Select(x => AssemblyName.GetAssemblyName(x.FullName))
    .Select(x => Assembly.Load(x.FullName)))
   {
    BuildManager.AddReferencedAssembly(a);
   }

  }
 }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Web;
using System.Web.Mvc;
using System.Web.WebPages.Razor;

namespace Plugins.Web
{
 public class CustomerViewEngine : RazorViewEngine
 {

  /// <summary>
  /// 定义视图页所在地址。
  /// </summary>
  private string[] _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",
  };
  public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
  {
   string ns = controllerContext.Controller.GetType().Namespace;
   string controller = 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);
   }
   return base.FindView(controllerContext, viewName, masterName, useCache);
  }
  /// <summary>
  /// 替换pluginFolder占位符
  /// </summary>
  /// <param name="folderName"></param>
  private string[] ReplacePlaceholder(string folderName)
  {
   string[] tempArray = new string[_viewLocationFormats.Length];
   if (_viewLocationFormats != null)
   {
    for (int i = 0; i < _viewLocationFormats.Length; i++)
    {
     tempArray[i] = _viewLocationFormats[i].Replace("{pluginFolder}", folderName);
    }
   }
   return tempArray;
  }
 }
}