一直以来，开发MVC3应用，在部署的时候为了方便，并不在用户环境安装MVC3，只是把用到的几个assembly直接部署到bin里，包括：

Microsoft.Web.Infrastructure.dll

System.Web.Helpers.dll

System.Web.MVC.dll

System.Web.WebPages.Deployment.dll

System.Web.WebPages.dll

System.Web.WebPages.Razor.dll


最近系统升级，再这么部署网站时，发现不好用了，报错：

Compiler Error Message: CS1705: Assembly 'TestUnsafe, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' uses 'System.Web.Mvc, Version=3.0.0.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'


发现没？System.Web.MVC的版本要求是3.0.0.1，而bin里放的仍然是3.0.0.0，肯定跑不起来。OK，换个新的程序集上去，把System.Web.MVC.dll 3.0.0.1版放上去，仍然跑不起来，报错：

Parser Error Message: Could not load file or assembly 'System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)


这是由于Web.config未更新导致的，找到下面的几行：

<runtime><assemblyBindingxmlns="urn:schemas-microsoft-com:asm.v1"><dependentAssembly><assemblyIdentityname="System.Web.Mvc"publicKeyToken="31bf3856ad364e35"/><bindingRedirectoldVersion="1.0.0.0-2.0.0.0"newVersion="3.0.0.0"/></dependentAssembly></assemblyBinding></runtime>


调整oldVersion和newVersion，改成：

<runtime><assemblyBindingxmlns="urn:schemas-microsoft-com:asm.v1"><dependentAssembly><assemblyIdentityname="System.Web.Mvc"publicKeyToken="31bf3856ad364e35"/><bindingRedirectoldVersion="1.0.0.0-3.0.0.0"newVersion="3.0.0.1"/></dependentAssembly></assemblyBinding></runtime>


看到没？把旧版本的MVC统一映射到3.0.0.1版去。再访问站点，一切正常了。