Dynamic Service Registration In ASP.NET Core Dependency Injection Container

Tanvir Ahmad Arjel

2 Comments

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Emundo Trivelli5y ago
This was super helpful for almost everything I've tried using it on, but I (may) have found a scenario that can cause it to break involving service inheritance: I've got two services, QueryableStatisticService and CensusStatisticService. CensusStatisticService inherits from QueryableStatisticService. Each of them has their own interface(IQueryableStatisticService and ICensusStatisticService), and ICensusStatisticService also inherits from IQueryableStatisticService. I've got the inheritance of IScopedService happening in IQueryableStatisticService. It seems like the service registration can be arbitrary in this scenario. I didn't touch this set-up at all from one changeset to another, but the registration of both service interfaces was mapped to CensusStatisticService instead of the prior case where each mapped neatly to their respective class. It's not really a solution, but manually adding service registration for each of these services to their respective interface in Startup.cs helped me get around this
ejaz mirza6y ago
getting run time errorCould not load type 'Microsoft.EntityFrameworkCore.Metadata.RelationalModelAnnotations' from assembly 'Microsoft.EntityFrameworkCore.Relational, Version=3.1.9.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'.

Introduction

In ASP.NET Core, whenever we inject a service as a dependency, we must register this service to ASP.NET Core Dependency Injection container. However, registering services one by one is not only tedious and time-consuming, but it is also error-prone. So here, we will discuss how we can register all the services at once dynamically.

Let's get started!

To register all of the services dynamically, we will use TanvirArjel.Extensions.Microsoft.DependencyInjection library. This is a small but extremely useful library that enables you to register all your services into ASP.NET Core Dependency Injection container at once without exposing the service implementation.

First, install the latest version of TanvirArjel.Extensions.Microsoft.DependencyInjection NuGet package into your project as follows,

Install-Package TanvirArjel.Extensions.Microsoft.DependencyInjection

Using Marker Interface

Now let your services inherit any of the ITransientService, IScoperService, and ISingletonService marker interfaces as follows,

using TanvirArjel.Extensions.Microsoft.DependencyInjection
// Inherit `IScopedService` interface if you want to register `IEmployeeService` as scoped service.
public class IEmployeeService : IScopedService
{
Task CreateEmployeeAsync(Employee employee);
}
internal class EmployeeService : IEmployeeService
{
public async Task CreateEmployeeAsync(Employee employee)
{
// Implementation here
};
}

ITransientService, IScoperService, and ISingletonService are available in TanvirArjel.Extensions.Microsoft.DependencyInjection namespace.

Using Attribute

Now mark your services with any of the ScopedServiceAttribute, TransientServiceAttribute, and SingletonServiceAttribute attributes as follows,

using TanvirArjel.Extensions.Microsoft.DependencyInjection
// Mark with ScopedServiceAttribute if you want to register `IEmployeeService` as scoped service.
[ScopedService]
public class IEmployeeService
{
Task CreateEmployeeAsync(Employee employee);
}
internal class EmployeeService : IEmployeeService
{
public async Task CreateEmployeeAsync(Employee employee)
{
// Implementation here
};
}

ScopedServiceAttribute, TransientServiceAttribute, and SingletonServiceAttribute are available in TanvirArjel.Extensions.Microsoft.DependencyInjection namespace.

Now in your ConfigureServices method of the Startup class,

public void ConfigureServices(IServiceCollection services)
{
services.AddServicesOfType<IScopedService>();
services.AddServicesWithAttributeOfType<ScopedServiceAttribute>();
}

AddServicesOfType<T> is available in TanvirArjel.Extensions.Microsoft.DependencyInjection namespace.

Moreover, if you want only specific assemblies to be scanned during type scanning,

public static void ConfigureServices(IServiceCollection services)
{
// Assemblies start with "TanvirArjel.Web", "TanvirArjel.Application" will only be scanned.
string[] assembliesToBeScanned = new string[] { "TanvirArjel.Web", "TanvirArjel.Application" };
services.AddServicesOfType<IScopedService>(assembliesToBeScanned);
services.AddServicesWithAttributeOfType<ScopedServiceAttribute>(assembliesToBeScanned);
}

Conclusion

That's it! The job is done! It is as simple as above to dynamically register all your services into ASP.NET Core Dependency Injection container at once. If you have any issues, you can submit it to the Github Repository of this library. You will be helped as soon as possible.

Thank you for reading!