我是MVC 4和Entity Framework的新手,当我在包管理器控制台中运行此命令时:
Enable-Migrations -ContextTypeName MyFirstMvcApp.Models.InventoryDbContext
连接路径:无法绑定参数“Path”,因为它为空。
我遇到了以下错误:
Join-Path : Cannot bind argument to parameter 'Path' because it is null.
At D:\GitProjects\MyFirstMvcApp\trunk\packages\EntityFramework.6.0.0-alpha2\tools\EntityFramework.psm1:363 char:27
+ $toolsPath = Join-Path <<<< $installPath tools
+ CategoryInfo : InvalidData: (:) [Join-Path], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.JoinPathCommand
Join-Path : Cannot bind argument to parameter 'Path' because it is null.
At D:\GitProjects\MyFirstMvcApp\trunk\packages\EntityFramework.6.0.0-alpha2\tools\EntityFramework.psm1:392 char:73
+ $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-Path <<<< $toolsPath EntityFramework.PowerShell.Utility.dll))
+ CategoryInfo : InvalidData: (:) [Join-Path], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.JoinPathCommand
You cannot call a method on a null-valued expression.
At D:\GitProjects\MyFirstMvcApp\trunk\packages\EntityFramework.6.0.0-alpha2\tools\EntityFramework.psm1:393 char:50
+ $dispatcher = $utilityAssembly.CreateInstance <<<< (
+ CategoryInfo : InvalidOperation: (CreateInstance:String) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
Join-Path : Cannot bind argument to parameter 'Path' because it is null.
At D:\GitProjects\MyFirstMvcApp\trunk\packages\EntityFramework.6.0.0-alpha2\tools\EntityFramework.psm1:426 char:19
+ (Join-Path <<<< $runner.ToolsPath EntityFramework.PowerShell.dll),
+ CategoryInfo : InvalidData: (:) [Join-Path], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.JoinPathCommand
我该如何修复这个问题? 请注意,我正在使用已安装MVC4的Visual Studio 2010 Ultimate SP1版本,链接为此处。
PM> Install-Package EntityFramework -Pre -Version 5.0.0
- nicemd