在ASP.NET核心中使用时,如何从另一个项目访问EF核心的DbContext? [英] How to I access the DbContext of EF core from another project when used in ASP.NET core?
问题描述
我遵循了将EF Core与ASP.NET core结合使用的模式,一切都很好。但是最近我创建了一个计算项目,并希望从中进行数据库调用。
I followed the pattern to use EF Core with ASP.NET core and all is well. But recently I created a 'Calculation' project and want to make database calls from it.
问题是我不知道如何创建新的 DbContextOptions
。在我的代码中使用
The problem is I don't know how to create a new DbContextOptions
. In my code that is done with
services.AddDbContext<RetContext>(options => options
.UseLazyLoadingProxies()
.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
但是在新的.NET核心类中,我需要手动提供它。我该怎么做呢 ?我的代码是这样的:
But in a new .NET core class I need to provide it manually. How do I do this ? My code is like this:
public static class LoadData
{
public static IConfiguration Configuration { get; }
public static RefProgramProfileData Load_RefProgramProfileData(string code)
{
// var optionsBuilder = new DbContextOptionsBuilder<RetContext>();
// optionsBuilder.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"));
//How do I make an optionsbuilder and get the configuration from the WEB project?
UnitOfWork uow = new UnitOfWork(new RetContext(optionsBuilder));
var loadedRefProgramProfileData = uow.RefProgramProfileDataRepository
.Find(x => x.ProgramCode == code).FirstOrDefault();
return loadedRefProgramProfileData;
}
}
推荐答案
您可以像这样实例化您的 DbContext
:
You may instantiate your DbContext
like this:
var builder = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json");
var configuration = builder.Build();
var optionsBuilder = new DbContextOptionsBuilder<RetContext>();
optionsBuilder.UseSqlServer(configuration.GetConnection("DefaultConnection"));
_context = new RetContext(optionsBuilder.Options);
但是,理想的情况是使用依赖注入。假设您在其他项目中有一个 CalculationService
类。为此,您需要将该类注册为可以注入的服务:
However, the ideal is to use dependency injection. Let's say you have a class CalculationService
in your other project. For that, you need to register that class as a service that can be injected:
services.AddScoped<CalculationService>();
然后您的班级将收到 DbContext
(或任何其他服务)通过DI:
Then your class can receive DbContext
(or any other services) through DI:
public class CalculationService
{
private RetContext _context;
public CalculationService(RetContext context)
{
_context = context;
}
}
自然,您将无法实例化您的实例像这样的手动类:
Naturally, you won't be able to instantiate your class manually like this:
var service = new CalculationService();
相反,您需要使任何类都需要使用 CalculationService
也可以通过DI接收它,并使该类也可以注入。
Instead, you'd need to make whatever class needs to use your CalculationService
to also receive it through DI and make that class injectable as well.
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