当我尝试启用EF 4.3.1中的迁移时引发异常 [英] Exception raised when I'm trying enable migrations in EF 4.3.1

问题描述

我正在使用由.net 4.0类库项目中的nuget安装的Entity框架4.3.1。在这种情况下，当我在PM控制台中调用Enable-Migrations命令时，我收到以下异常：

I'm using Entity framework 4.3.1 installed by nuget in my .Net 4.0 class library project. In situation, when I call the "Enable-Migrations" command in PM console, I receive following exception:

异常调用LoadFrom 1参数：Nelzenačístsoubor nebosestavenífile：/// D：\
Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\ EntityFramework.4.3.1\to
ols\EntityFramework.PowerShell.Utility.dll nebo jeden z jejichzávislýchprvků。Systémnemůženalé
ztuvedenýsoubor。
在D：\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5。
0.0-rc\tools\EntityFramework.psm1：393 char：62
+ $ utilityAssembly = [System.Reflection.Assembly] :: LoadFrom<<<< （（Join-Path $ toolsPath Entity
Framework.PowerShell.Utility.dll））
+ CategoryInfo：NotSpecified：（:) []，MethodInvocationException
+ FullyQualifiedErrorId：DotNetMethodException

Exception calling "LoadFrom" with "1" argument(s): "Nelze načíst soubor nebo sestavení file:///D:\ Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.4.3.1\to ols\EntityFramework.PowerShell.Utility.dll nebo jeden z jejich závislých prvků. Systém nemůže nalé zt uvedený soubor." At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5. 0.0-rc\tools\EntityFramework.psm1:393 char:62 + $utilityAssembly = [System.Reflection.Assembly]::LoadFrom <<<< ((Join-Path $toolsPath Entity Framework.PowerShell.Utility.dll)) + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : DotNetMethodException

您无法在空值表达式上调用方法。
在D：\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5。
0.0-rc\tools\EntityFramework.psm1：394 char：50
+ $ dispatcher = $ utilityAssembly.CreateInstance<<<<< （
+ CategoryInfo：InvalidOperation：（CreateInstance：String）[]，RuntimeException
+ FullyQualifiedErrorId：InvokeMethodOnNull

You cannot call a method on a null-valued expression. At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5. 0.0-rc\tools\EntityFramework.psm1:394 char:50 + $dispatcher = $utilityAssembly.CreateInstance <<<< ( + CategoryInfo : InvalidOperation: (CreateInstance:String) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

异常调用CreateInstanceFrom 参数：Typ System.Data.Entity.Migrations.En
ableMigrationsCommand zesestaveníEntityFramework.PowerShell，Version = 4.3.1.0，Culture = neutral，P
ublicKeyToken = b77a5c561934e089 nelzenačíst。
在D：\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5。
0.0-rc\tools\EntityFramework。 psm1：418 char：31> + $ domain.CreateInstanceFrom<<<（
+ CategoryInfo：NotSpecified：（:) []，MethodInvocationException
+ FullyQualifiedErrorId：DotNetMethodException

Exception calling "CreateInstanceFrom" with "8" argument(s): "Typ System.Data.Entity.Migrations.En ableMigrationsCommand ze sestavení EntityFramework.PowerShell, Version=4.3.1.0, Culture=neutral, P ublicKeyToken=b77a5c561934e089 nelze načíst." At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5. 0.0-rc\tools\EntityFramework.psm1:418 char:31>+ $domain.CreateInstanceFrom <<<< ( + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : DotNetMethodException

推荐答案

我解决了上述问题。

1. 我卸载了Entity fra使用NuGet软件包管理器进行作业。


2. 我手动清除了在包
   目录中以Entity开头的子目录。


3. 我安装了Entity Framework 4.3 .1再次

现在迁移正确启用。

这篇关于当我尝试启用EF 4.3.1中的迁移时引发异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！