VS2017 中的 .NET Core 1.1：DbContextOptionsBuilder 不包含“UseSqlServer”的定义

Question

在 VS2017 中处理一个新项目，但是当我为我的 dbContext 输入服务时，我收到此错误：

Error   CS1061  'DbContextOptionsBuilder' does not contain a definition for 
'UseSqlServer' and no extension method 'UseSqlServer' accepting a first 
argument of type 'DbContextOptionsBuilder' could be found (are you missing a 
using directive or an assembly reference?)  

Microsoft.EntityFrameworkCore.SqlServer v1.1.1 不再包含此功能还是我遗漏了什么？

.csproj

<PropertyGroup>
<TargetFramework>netcoreapp1.1</TargetFramework>
</PropertyGroup>

<PropertyGroup>
<PackageTargetFallback>$(PackageTargetFallback);portable- 
net45+win8+wp8+wpa81;</PackageTargetFallback>
<ApplicationIcon />
<OutputTypeEx>exe</OutputTypeEx>
<StartupObject />
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" 
Version="2.0.0" />
<PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" 
/>
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" 
Version="1.1.1" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" 
Version="1.1.1" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" 
Version="1.1.1" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" 
Version="1.1.0" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" 
Version="1.1.1" />
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" 
Version="1.1.0" />
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" 
Version="1.1.0" />
<PackageReference Include="Novell.Directory.ldap.netstandard" 
Version="2.3.6" />
</ItemGroup>
<ItemGroup>
<DotNetCliToolReference 
Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
</ItemGroup>
<ItemGroup>
<WCFMetadata Include="Connected Services" />
</ItemGroup>

</Project>

Answer 1

我必须从 NuGet 安装“Microsoft.EntityFrameworkCore.SqlServer”。

在我运行的包管理器控制台中：Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 1.1.2

我还必须确保在 Startup.cs 文件中使用 using 语句引用了 Microsoft.EntityFrameworkCore：using Microsoft.EntityFrameworkCore;。

Answer 2

正如错误所说，

...（您是否缺少 using 指令或程序集引用？）

这是一种扩展方法，所以你需要using Microsoft.EntityFrameworkCore;