配置服务时出错 - 将 Entity Framework Core 添加到 ASP.NET Core

Question

I have created an ASP.NET Core web application. I am trying to add Entity Framework Core to my solution.

I have installed the below nugets to the project.

• "Microsoft.NETCore.App",
• "Microsoft.AspNetCore.App"
• "Microsoft.EntityFrameworkCore.SqlServer"

There is a DbSet defined in the Context.

In the startup class when i try to add the Db Context, I get the following error in the for "Configuration".

The Name Configuration does not exist in the current context.

My code is:

public void ConfigureServices(IServiceCollection services)
{
    services.AddDbContext<MyContext>(options => 
    options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
}

I am following this article which doesn't say much about the configuration

Answer 1

The code sample is incomplete. The Configuration actually is a property of the Startup class. It is populated via constructor dependency injection.

public class Startup
{
    public IConfiguration Configuration { get; }

    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddDbContext<MyContext>(options => 
        options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
    }

    //...
}

As mentioned on the last step of the article : the full code is available on https://github.com/aspnet/AspNetCore.Docs/tree/master/aspnetcore/data/ef-mvc/intro/samples/cu-final