OWinStartup，未找到 OWinStartupAttribute 并且“Owin.IAppBuilder”不包含“地图”的定义答案

【问题标题】：OWinStartup, OWinStartupAttribute not found & 'Owin.IAppBuilder' does not contain a definition for 'Map'OWinStartup，未找到 OWinStartupAttribute 并且“Owin.IAppBuilder”不包含“地图”的定义
【发布时间】：2015-03-03 12:07:45
【问题描述】：

在将我的 asp.net webform 网站从 Owin 2.1.0 升级到 Owin 3.0.1 后，我遇到了前面提到的编译错误......我也在尝试使用 SignalR 2 和 CORS。这是我的 packages.config：

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="jQuery" version="2.1.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.Cors" version="5.2.3" targetFramework="net45" />
  <package id="Microsoft.AspNet.SignalR" version="2.2.0" targetFramework="net45" />
  <package id="Microsoft.AspNet.SignalR.Core" version="2.2.0" targetFramework="net45" />
  <package id="Microsoft.AspNet.SignalR.JS" version="2.2.0" targetFramework="net45" />
  <package id="Microsoft.AspNet.SignalR.SystemWeb" version="2.2.0" targetFramework="net45" />
  <package id="Microsoft.Owin" version="3.0.1" targetFramework="net45" />
  <package id="Microsoft.Owin.Cors" version="3.0.1" targetFramework="net45" />
  <package id="Microsoft.Owin.Host.SystemWeb" version="3.0.1" targetFramework="net45" />
  <package id="Microsoft.Owin.Security" version="3.0.1" targetFramework="net45" />
  <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net45" />
  <package id="Owin" version="1.0" targetFramework="net45" />
</packages>

我的 OwinStartup 类在 appsettings 的 web.config 中定义如下：

<add key="owin:AppStartup" value="SignalRStartup, App_Code" />

这就是类的样子：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Owin;
using Microsoft.Owin;
using Microsoft.AspNet.SignalR;
using Microsoft.Owin.Cors;
using System.IO;

[assembly: OwinStartup(typeof(SignalRStartup))]
public class SignalRStartup
{
    public void Configuration(IAppBuilder app)
    {

        // Enable detailed errors (remember to remove it
        var hubConfiguration = new HubConfiguration();
        hubConfiguration.EnableDetailedErrors = true;
        //hubConfiguration.EnableCrossDomain = true;
        app.UseCors(CorsOptions.AllowAll);
        app.MapSignalR(hubConfiguration);
    }
}

还要注意我不能使用app.Map("/signalr", map => { ... });...

编辑：我在 web.config 中找到了升级前没有的那些行：

<runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2.1.0.0" newVersion="3.0.1.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Cors" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

我要放弃了，如果你有任何想法，请...

【问题讨论】：

如果从配置文件中删除启动属性会发生什么。如果您还使用程序集属性，我认为您不需要这个
也是一样，编译的时候挂在'OWinStartup'上找不到（是不是少了一个using指令...

标签： asp.net webforms signalr owin

【解决方案1】：

耶！找到了！非常感谢这篇文章： The type or namespace IAppBuilder could not be found(missing using a directive pr an assembly reference).

通过重新安装 Microsoft.owin 解决了我的问题，如 Иво Недев 建议的：

PM> Update-Package Microsoft.Owin -Reinstall
Removing 'Microsoft.Owin 3.0.1' from ww.
Value does not fall within the expected range.
Successfully removed 'Microsoft.Owin 3.0.1' from ww.
Removing 'Owin 1.0' from ww.
Successfully removed 'Owin 1.0' from ww.
Uninstalling 'Microsoft.Owin 3.0.1'.
Successfully uninstalled 'Microsoft.Owin 3.0.1'.
Uninstalling 'Owin 1.0'.
Successfully uninstalled 'Owin 1.0'.
Attempting to resolve dependency 'Owin (≥ 1.0)'.
Installing 'Owin 1.0'.
Successfully installed 'Owin 1.0'.
Installing 'Microsoft.Owin 3.0.1'.
You are downloading Microsoft.Owin from Microsoft, the license agreement to which is available at http://www.microsoft.com/web/webpi/eula/net_library_eula_enu.htm. Check the package for additional dependencies, which may come with their own license agreement(s). Your use of the package and dependencies constitutes your acceptance of their license agreements. If you do not accept the license agreement(s), then delete the relevant components from your device.
Successfully installed 'Microsoft.Owin 3.0.1'.
Adding 'Owin 1.0' to ww.
Successfully added 'Owin 1.0' to ww.
Adding 'Microsoft.Owin 3.0.1' to ww.
Successfully added 'Microsoft.Owin 3.0.1' to ww.

我的头现在可以止血了：-P

【讨论】：