我有一个ASP。NET MVC5应用程序，昨天工作，现在我得到这个错误时，我试图构建:
该项目引用了这台计算机上缺少的NuGet包。
我已经检查了两个选项，允许nuget自动下载和安装丢失的包检查/打开。我还尝试删除packages文件夹中的所有文件，然后让nuget重新下载它们。另外，当我打开nuget并寻找更新时，它说没有需要安装的。我想不出还能做些什么来解决这个恼人的问题。
我还通过右键单击项目并选择该选项启用了nuget恢复。然后，它添加了一个nuget文件夹和该文件夹中的三个项目，但没有采取任何措施来解决问题。我已经尝试重新构建，但仍然得到相同的错误。
当前回答
首先要尝试的是右键单击解决方案并选择“Restore Nuget Packages”。
在我的情况下，这并不管用，所以我遵循了一些删除项目文件上的“导入”和“目标”的建议，这适用于我的3个项目中的2个，但在最后一个项目上得到了不同的错误。
工作的是打开包管理器控制台并运行:
Update-Package -reinstall -ProjectName MyProjectName
这需要一些时间，但由于它重新安装所有的包，你的项目将编译没有问题
其他回答
我有同样的问题，当我引用类库到我的MVC web应用程序，
问题是两个项目之间的nuget包版本号不匹配。
例如:我的类库有1.2.3的log4net，但我的webapp有1.2.6
修正:只要确保两个项目有相同的版本号引用。
在.csproj文件中删除以下行
<Import Project="$(SolutionDir)\.nuget\NuGet.targets"
Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
<Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
<PropertyGroup>
<ErrorText>This project references NuGet package(s) that are missing on this computer.
Enable NuGet Package Restore to download them. For more information, see
http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
</PropertyGroup>
<Error Condition="!Exists('$(SolutionDir)\.nuget\NuGet.targets')"
Text="$([System.String]::Format('$(ErrorText)',
'$(SolutionDir)\.nuget\NuGet.targets'))" />
</Target>
经过一段时间解决这个问题。 只需添加一个包源https://api.nuget.org/v3/index.json解决我这边的错误
是否有可能包已经恢复到错误的文件夹?检查csproj文件中的路径是否正确。
如果它们不同，则可能是由于包现在被恢复到不同的位置造成的。这可能是由NuGet引起的。在指定节点时检查配置文件，如下所示:
<add key="repositoryPath" value="..\..\Packages" />
这些包正在被修复，项目仍然在寻找旧的位置。
我创建了一个名为'的文件夹。解决方案根文件夹中的Nuget 然后添加文件'NuGet。配置'在此文件夹中的以下内容
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<solution>
<add key="disableSourceControlIntegration" value="true" />
</solution>
</configuration>
然后创建文件'. nuget。目标如下 $ (MSBuildProjectDirectory) . . \
<!-- Enable the restore command to run before builds -->
<RestorePackages Condition=" '$(RestorePackages)' == '' ">false</RestorePackages>
<!-- Property that enables building a package from a project -->
<BuildPackage Condition=" '$(BuildPackage)' == '' ">false</BuildPackage>
<!-- Determines if package restore consent is required to restore packages -->
<RequireRestoreConsent Condition=" '$(RequireRestoreConsent)' != 'false' ">true</RequireRestoreConsent>
<!-- Download NuGet.exe if it does not already exist -->
<DownloadNuGetExe Condition=" '$(DownloadNuGetExe)' == '' ">false</DownloadNuGetExe>
</PropertyGroup>
<ItemGroup Condition=" '$(PackageSources)' == '' ">
<!-- Package sources used to restore packages. By default will used the registered sources under %APPDATA%\NuGet\NuGet.Config -->
<!--
<PackageSource Include="https://nuget.org/api/v2/" />
<PackageSource Include="https://my-nuget-source/nuget/" />
-->
</ItemGroup>
<PropertyGroup Condition=" '$(OS)' == 'Windows_NT'">
<!-- Windows specific commands -->
<NuGetToolsPath>$([System.IO.Path]::Combine($(SolutionDir), ".nuget"))</NuGetToolsPath>
<PackagesConfig>$([System.IO.Path]::Combine($(ProjectDir), "packages.config"))</PackagesConfig>
<PackagesDir>$([System.IO.Path]::Combine($(SolutionDir), "packages"))</PackagesDir>
</PropertyGroup>
<PropertyGroup Condition=" '$(OS)' != 'Windows_NT'">
<!-- We need to launch nuget.exe with the mono command if we're not on windows -->
<NuGetToolsPath>$(SolutionDir).nuget</NuGetToolsPath>
<PackagesConfig>packages.config</PackagesConfig>
<PackagesDir>$(SolutionDir)packages</PackagesDir>
</PropertyGroup>
<PropertyGroup>
<!-- NuGet command -->
<NuGetExePath Condition=" '$(NuGetExePath)' == '' ">$(NuGetToolsPath)\nuget.exe</NuGetExePath>
<PackageSources Condition=" $(PackageSources) == '' ">@(PackageSource)</PackageSources>
<NuGetCommand Condition=" '$(OS)' == 'Windows_NT'">"$(NuGetExePath)"</NuGetCommand>
<NuGetCommand Condition=" '$(OS)' != 'Windows_NT' ">mono --runtime=v4.0.30319 $(NuGetExePath)</NuGetCommand>
<PackageOutputDir Condition="$(PackageOutputDir) == ''">$(TargetDir.Trim('\\'))</PackageOutputDir>
<RequireConsentSwitch Condition=" $(RequireRestoreConsent) == 'true' ">-RequireConsent</RequireConsentSwitch>
<!-- Commands -->
<RestoreCommand>$(NuGetCommand) install "$(PackagesConfig)" -source "$(PackageSources)" $(RequireConsentSwitch) -o "$(PackagesDir)"</RestoreCommand>
<BuildCommand>$(NuGetCommand) pack "$(ProjectPath)" -p Configuration=$(Configuration) -o "$(PackageOutputDir)" -symbols</BuildCommand>
<!-- Make the build depend on restore packages -->
<BuildDependsOn Condition="$(RestorePackages) == 'true'">
RestorePackages;
$(BuildDependsOn);
</BuildDependsOn>
<!-- Make the build depend on restore packages -->
<BuildDependsOn Condition="$(BuildPackage) == 'true'">
$(BuildDependsOn);
BuildPackage;
</BuildDependsOn>
</PropertyGroup>
<Target Name="CheckPrerequisites">
<!-- Raise an error if we're unable to locate nuget.exe -->
<Error Condition="'$(DownloadNuGetExe)' != 'true' AND !Exists('$(NuGetExePath)')" Text="Unable to locate '$(NuGetExePath)'" />
<SetEnvironmentVariable EnvKey="VisualStudioVersion" EnvValue="$(VisualStudioVersion)" Condition=" '$(VisualStudioVersion)' != '' AND '$(OS)' == 'Windows_NT' " />
<DownloadNuGet OutputFilename="$(NuGetExePath)" Condition=" '$(DownloadNuGetExe)' == 'true' AND !Exists('$(NuGetExePath)')" />
</Target>
<Target Name="RestorePackages" DependsOnTargets="CheckPrerequisites">
<Exec Command="$(RestoreCommand)"
Condition="'$(OS)' != 'Windows_NT' And Exists('$(PackagesConfig)')" />
<Exec Command="$(RestoreCommand)"
LogStandardErrorAsError="true"
Condition="'$(OS)' == 'Windows_NT' And Exists('$(PackagesConfig)')" />
</Target>
<Target Name="BuildPackage" DependsOnTargets="CheckPrerequisites">
<Exec Command="$(BuildCommand)"
Condition=" '$(OS)' != 'Windows_NT' " />
<Exec Command="$(BuildCommand)"
LogStandardErrorAsError="true"
Condition=" '$(OS)' == 'Windows_NT' " />
</Target>
<UsingTask TaskName="DownloadNuGet" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<OutputFilename ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Reference Include="System.Core" />
<Using Namespace="System" />
<Using Namespace="System.IO" />
<Using Namespace="System.Net" />
<Using Namespace="Microsoft.Build.Framework" />
<Using Namespace="Microsoft.Build.Utilities" />
<Code Type="Fragment" Language="cs">
<![CDATA[
try {
OutputFilename = Path.GetFullPath(OutputFilename);
Log.LogMessage("Downloading latest version of NuGet.exe...");
WebClient webClient = new WebClient();
webClient.DownloadFile("https://nuget.org/nuget.exe", OutputFilename);
return true;
}
catch (Exception ex) {
Log.LogErrorFromException(ex);
return false;
}
]]>
</Code>
</Task>
</UsingTask>
<UsingTask TaskName="SetEnvironmentVariable" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<EnvKey ParameterType="System.String" Required="true" />
<EnvValue ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Using Namespace="System" />
<Code Type="Fragment" Language="cs">
<![CDATA[
try {
Environment.SetEnvironmentVariable(EnvKey, EnvValue, System.EnvironmentVariableTarget.Process);
}
catch {
}
]]>
</Code>
</Task>
</UsingTask>
