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名称空间系统中不存在Mvc。网状物

Be Kind To New Users · 技术社区 · 8 年前

我正在使用Visual Studio 2017,出现以下错误:

命名空间“系统”中不存在类型或命名空间名称“Mvc”。Web'(是否缺少装配参考?)

在这行代码中:

using System.Web.Mvc;

这是解决问题所需要的 SelectListItem 在这行代码中:

public static List<SelectListItem> VerificationMethod

我希望添加一个程序集引用可以很容易地解决这个问题。

这是我试过的。。。。

我试图通过右键单击项目并选择 Add -> Reference . System.Web.Mvc 不在要添加的引用列表中。

其他一些帖子引用了这个软件包 Microsoft.Aspnet.Mvc 解决这个问题。这个包裹也没有。

我在nuget控制台上试过:

PM> Install-Package System.Web.mvc
Install-Package : Unable to find package 'System.Web.mvc'
At line:1 char:1
+ Install-Package System.Web.mvc
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand

我也试过:

PM> Install-Package Microsoft.aspnet.mvc
Package 'Microsoft.aspnet.mvc.5.2.6' already exists in project 'MySite'
Time Elapsed: 00:00:00.0549251
PM>

我也试过:

update-package -reinstall Microsoft.AspNet.Mvc

得到了这个错误:

安装失败。后退。。。
项目“DataAccess”中不存在包“EntityFramework 6.1.0”

2 回复 | 直到 8 年前

Be Kind To New Users 8 年前

以下是我们所做的工作。。。。

已删除中的所有文件和文件夹 packages 解决方案中的文件夹。

跑:

Update-Package -safe -reinstall -IgnoreDependencies
Install-Package Microsoft.AspNet.Mvc -Version 5.2.3.0

Be Kind To New Users 8 年前

请你试试下面的方法好吗

在DataAccess项目中>参考资料>右键点击系统。网状物mvc和删除。

从package manager控制台将项目更改为DataAccess,请参见下图

然后在package manager控制台中键入:

Install-Package Microsoft.AspNet.Mvc -Version 5.2.3.0

[按OP编辑] 这是我尝试这个的时候得到的:

PM> Install-Package Microsoft.AspNet.Mvc -Version 5.2.3.0


Attempting to gather dependency information for package 'Microsoft.AspNet.Mvc.5.2.3' with respect to project 'DataAccess', targeting '.NETFramework,Version=v4.5'
Gathering dependency information took 2.37 sec
Attempting to resolve dependencies for package 'Microsoft.AspNet.Mvc.5.2.3' with DependencyBehavior 'Lowest'
One or more unresolved package dependency constraints detected in the existing packages.config file. All dependency constraints must be resolved to add or update packages. If these packages are being updated this message may be ignored, if not the following error(s) may be blocking the current package operation: 'Microsoft.AspNet.Identity.EntityFramework 2.2.1 constraint: Microsoft.AspNet.Identity.Core (>= 2.2.1)', 'Microsoft.AspNet.Identity.EntityFramework 2.2.1 constraint: EntityFramework (>= 6.1.0)'
Resolving dependency information took 0 ms
Resolving actions to install package 'Microsoft.AspNet.Mvc.5.2.3'
Resolved actions to install package 'Microsoft.AspNet.Mvc.5.2.3'
Found package 'Microsoft.AspNet.Mvc 5.2.3' in 'C:\ThePath\packages'.
Found package 'Microsoft.AspNet.Razor 3.2.3' in 'C:\ThePath\packages'.
Found package 'Microsoft.AspNet.WebPages 3.2.3' in 'C:\ThePath\packages'.
Found package 'Microsoft.Web.Infrastructure 1.0.0' in 'C:\ThePath\packages'.
Package 'Microsoft.AspNet.Razor.3.2.3' already exists in folder 'C:\THePath\packages'
Added package 'Microsoft.AspNet.Razor.3.2.3' to 'packages.config'
Successfully installed 'Microsoft.AspNet.Razor 3.2.3' to DataAccess
Package 'Microsoft.Web.Infrastructure.1.0.0' already exists in folder 'C:ThePath\packages'
Install failed. Rolling back...
Package 'Microsoft.Web.Infrastructure.1.0.0' does not exist in project 'DataAccess'
Removed package 'Microsoft.AspNet.Razor.3.2.3' from 'packages.config'
Executing nuget actions took 389.27 ms
Install-Package : Failed to add reference to 'Microsoft.Web.Infrastructure'.
  Reference unavailable.
At line:1 char:1
+ Install-Package Microsoft.AspNet.Mvc -Version 5.2.3.0
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Install-Package], Exception
    + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand