asp.net-core Dependency Injection Register dependencies
Example
Builtin container comes with a set of builtin features :
Lifetime control
public void ConfigureServices(IServiceCollection services)
{
// ...
services.AddTransient<ITestService, TestService>();
// or
services.AddScoped<ITestService, TestService>();
// or
services.AddSingleton<ITestService, TestService>();
// or
services.AddSingleton<ITestService>(new TestService());
}
- AddTransient: Created everytime it is resolved
- AddScoped: Created once per request
- AddSingleton: Lazily created once per application
- AddSingleton (instance): Provides a previously created instance per application
Enumerable dependencies
It is also possible to register enumerable dependencies :
services.TryAddEnumerable(ServiceDescriptor.Transient<ITestService, TestServiceImpl1>());
services.TryAddEnumerable(ServiceDescriptor.Transient<ITestService, TestServiceImpl2>());
You can then consume them as follows :
public class HomeController : Controller
{
public HomeController(IEnumerable<ITestService> services)
{
// do something with services.
}
}
Generic dependencies
You can also register generic dependencies :
services.Add(ServiceDescriptor.Singleton(typeof(IKeyValueStore<>), typeof(KeyValueStore<>)));
And then consume it as follows :
public class HomeController : Controller
{
public HomeController(IKeyValueStore<UserSettings> userSettings)
{
// do something with services.
}
}
