What is the primary purpose of Dependency Injection (DI) in ASP.NET Core?
a. To manage the dependencies between objects and promote loose coupling
b. To handle HTTP requests and responses
c. To configure middleware components
d. To define routes for HTTP requests
Answer: a. To manage the dependencies between objects and promote loose coupling
Which method is used to register services in the ASP.NET Core dependency injection container?
a. AddScoped(), AddTransient(), and AddSingleton() in the ConfigureServices() method
b. ConfigureServices() method in the Startup class
c. RegisterServices() method in the Startup class
d. Define services in web.config
Answer: a. AddScoped(), AddTransient(), and AddSingleton() in the ConfigureServices() method
What is the difference between AddTransient() and AddScoped() in ASP.NET Core DI?
a. AddTransient() creates a new instance of the service each time it is requested, while AddScoped() creates a new instance per request
b. AddTransient() creates a new instance per request, while AddScoped() creates a singleton instance
c. Both methods create singleton instances
d. Both methods create new instances for each request
Answer: a. AddTransient() creates a new instance of the service each time it is requested, while AddScoped() creates a new instance per request
What is the role of AddSingleton() in dependency injection?
a. To register a service as a singleton, meaning one instance is shared throughout the application’s lifetime
b. To create a new instance of the service for each request
c. To create a new instance of the service for each scope
d. To register a service that is only used within a specific controller
Answer: a. To register a service as a singleton, meaning one instance is shared throughout the application’s lifetime
How do you inject a service into a controller in ASP.NET Core?
a. By adding the service to the constructor of the controller
b. By using the [Inject] attribute on the controller class
c. By configuring the service in web.config
d. By using a service locator pattern
Answer: a. By adding the service to the constructor of the controller
What is constructor injection in the context of dependency injection?
a. Passing dependencies through the constructor of a class
b. Injecting dependencies via properties
c. Using method parameters to inject dependencies
d. Retrieving dependencies from a service locator
Answer: a. Passing dependencies through the constructor of a class
How can you register a service with a specific lifetime?
a. By using AddTransient(), AddScoped(), or AddSingleton() methods in the ConfigureServices() method
b. By defining the lifetime in web.config
c. By using the [ServiceLifetime] attribute on services
d. By setting the lifetime in the controller constructor
Answer: a. By using AddTransient(), AddScoped(), or AddSingleton() methods in the ConfigureServices() method
What is the scope of a service registered with AddScoped()?
a. The service is created once per request
b. The service is created once per application
c. The service is created every time it is requested
d. The service is created once per controller
Answer: a. The service is created once per request
What is the scope of a service registered with AddSingleton()?
a. The service is created once per application and shared across all requests
b. The service is created once per request
c. The service is created every time it is requested
d. The service is created once per scope
Answer: a. The service is created once per application and shared across all requests
How can you resolve a service from the dependency injection container?
a. By injecting the service into a constructor or method
b. By using the ServiceProvider.GetService() method
c. By using the [Inject] attribute on properties
d. By defining the service in web.config
Answer: a. By injecting the service into a constructor or method
What is method injection in dependency injection?
a. Providing dependencies through method parameters
b. Passing dependencies through the constructor
c. Injecting dependencies via properties
d. Using a service locator pattern
Answer: a. Providing dependencies through method parameters
What is property injection in the context of DI?
a. Assigning dependencies to properties of a class after construction
b. Passing dependencies through the constructor
c. Injecting dependencies via method parameters
d. Using a service locator pattern
Answer: a. Assigning dependencies to properties of a class after construction
What is the purpose of the IServiceCollection interface?
a. To register services and their lifetimes with the dependency injection container
b. To handle HTTP requests and responses
c. To configure middleware components
d. To define routes for HTTP requests
Answer: a. To register services and their lifetimes with the dependency injection container
How do you register a service that needs to be injected into other services?
a. By registering the service in the ConfigureServices() method using AddTransient(), AddScoped(), or AddSingleton()
b. By defining the service in web.config
c. By using attributes on the service class
d. By configuring the service in the Startup constructor
Answer: a. By registering the service in the ConfigureServices() method using AddTransient(), AddScoped(), or AddSingleton()
What is the primary use of the IServiceProvider interface?
a. To resolve services from the dependency injection container
b. To register services with the dependency injection container
c. To manage request routing
d. To configure middleware components
Answer: a. To resolve services from the dependency injection container
How do you ensure that a service is resolved from the same instance within a request scope?
a. By registering the service with AddScoped()
b. By registering the service with AddSingleton()
c. By registering the service with AddTransient()
d. By using a service locator pattern
Answer: a. By registering the service with AddScoped()
How can you access the dependency injection container outside of a controller?
a. By using IServiceProvider and calling GetService() or GetRequiredService()
b. By configuring services in web.config
c. By using attributes on classes
d. By defining services in the Startup constructor
Answer: a. By using IServiceProvider and calling GetService() or GetRequiredService()
What is the purpose of the AddTransient() method in service registration?
a. To create a new instance of the service every time it is requested
b. To create a singleton instance shared across the application
c. To create a new instance per request
d. To configure service dependencies
Answer: a. To create a new instance of the service every time it is requested
How can you configure a service with a specific implementation in ASP.NET Core DI?
a. By specifying the implementation type when registering the service
b. By defining the implementation in web.config
c. By using attributes on the service class
d. By configuring services in the Startup constructor
Answer: a. By specifying the implementation type when registering the service
What method is used to register a service with a specific interface in ASP.NET Core?
a. AddTransient<TService, TImplementation>()
b. AddScoped<TImplementation, TService>()
c. AddSingleton<TService>(new TService())
d. RegisterService<TService>()
Answer: a. AddTransient<TService, TImplementation>()
How can you ensure that a specific implementation is used for a given interface?
a. By registering the implementation type with the interface type in the ConfigureServices() method
b. By defining implementations in web.config
c. By using attributes on the interface
d. By configuring implementations in the Startup constructor
Answer: a. By registering the implementation type with the interface type in the ConfigureServices() method
What is the role of the IServiceCollection.Configure() method?
a. To configure options or settings for a service
b. To register new services with the DI container
c. To resolve services from the container
d. To define middleware components
Answer: a. To configure options or settings for a service
How do you handle circular dependencies in ASP.NET Core DI?
a. By refactoring the code to eliminate circular references
b. By using the [Inject] attribute
c. By defining circular dependencies in web.config
d. By using a service locator pattern
Answer: a. By refactoring the code to eliminate circular references
What is the purpose of the GetRequiredService() method?
a. To retrieve a service from the container and throw an exception if the service is not found
b. To resolve a service from the container if it exists
c. To register a new service with the container
d. To configure services in the Startup class
Answer: a. To retrieve a service from the container and throw an exception if the service is not found
How can you use dependency injection to inject configuration settings?
a. By using the IConfiguration interface and injecting it into the constructor
b. By defining settings in web.config
c. By using the [Inject] attribute on properties
d. By configuring settings in the Startup constructor
Answer: a. By using the IConfiguration interface and injecting it into the constructor
What is the primary purpose of the IOptions<T> interface in ASP.NET Core?
a. To provide a way to access configuration settings in a strongly-typed manner
b. To register services with the DI container
c. To handle HTTP requests and responses
d. To configure middleware components
Answer: a. To provide a way to access configuration settings in a strongly-typed manner
How do you configure a service to be used as a singleton but only for a specific scope?
a. By using the AddSingleton() method and implementing custom scope logic within the service
b. By using the AddScoped() method
c. By using the AddTransient() method
d. By defining a custom lifetime in the Startup constructor
Answer: a. By using the AddSingleton() method and implementing custom scope logic within the service
What is the role of the ServiceLifetime enum in ASP.NET Core DI?
a. To define the lifetime of a service (Transient, Scoped, Singleton)
b. To specify the version of a service
c. To configure the service in web.config
d. To register the service with the DI container
Answer: a. To define the lifetime of a service (Transient, Scoped, Singleton)
How do you register multiple implementations for the same service type?
a. By using AddTransient(), AddScoped(), or AddSingleton() methods and resolving them via IEnumerable<T>
b. By defining multiple implementations in web.config
c. By using attributes on the service class
d. By configuring services in the Startup constructor
Answer: a. By using AddTransient(), AddScoped(), or AddSingleton() methods and resolving them via IEnumerable<T>
What is the purpose of the IServiceScopeFactory interface?
a. To create and manage service scopes for dependency resolution
b. To configure services with specific settings
c. To handle HTTP requests and responses
d. To define middleware components
Answer: a. To create and manage service scopes for dependency resolution
How do you resolve a scoped service from a singleton service?
a. By using IServiceScopeFactory to create a scope and resolve the scoped service
b. By injecting the scoped service directly into the singleton
c. By configuring the service in web.config
d. By using the [Inject] attribute
Answer: a. By using IServiceScopeFactory to create a scope and resolve the scoped service
How can you implement a custom service provider in ASP.NET Core?
a. By creating a class that implements IServiceProvider and configuring it in the Startup class
b. By defining a custom service provider in web.config
c. By using attributes on services
d. By implementing a custom service locator
Answer: a. By creating a class that implements IServiceProvider and configuring it in the Startup class
What is the role of the IHostBuilder interface in ASP.NET Core?
a. To configure and build the host for the application, including dependency injection
b. To register services with the DI container
c. To handle HTTP requests and responses
d. To configure middleware components
Answer: a. To configure and build the host for the application, including dependency injection
How do you inject a service into a Razor Page?
a. By adding the service to the constructor of the Razor Page
b. By using the [Inject] attribute on the page
c. By configuring services in web.config
d. By using attributes on the Razor Page
Answer: a. By adding the service to the constructor of the Razor Page
What is the purpose of the AddHttpClient() method in ASP.NET Core?
a. To configure and register an HTTP client for dependency injection
b. To handle HTTP requests and responses
c. To configure middleware for HTTP requests
d. To define routing for HTTP requests
Answer: a. To configure and register an HTTP client for dependency injection
How can you inject services into middleware components?
a. By adding the service to the constructor of the middleware
b. By using the [Inject] attribute on the middleware class
c. By configuring services in web.config
d. By defining services in the Startup constructor
Answer: a. By adding the service to the constructor of the middleware
What is the purpose of the IServiceProvider.GetService() method?
a. To resolve a service from the dependency injection container
b. To register a new service with the container
c. To configure middleware components
d. To handle HTTP requests and responses
Answer: a. To resolve a service from the dependency injection container
How do you manage the lifecycle of a service that requires initialization before use?
a. By using the factory pattern in service registration to initialize the service
b. By configuring the service in web.config
c. By using the [Inject] attribute on the service class
d. By setting up initialization logic in the Startup constructor
Answer: a. By using the factory pattern in service registration to initialize the service
What is the purpose of the IServiceScope interface?
a. To manage a scope for service resolution, ensuring services are disposed correctly
b. To configure services with specific settings
c. To handle HTTP requests and responses
d. To define middleware components
Answer: a. To manage a scope for service resolution, ensuring services are disposed correctly
How can you override a service implementation at runtime?
a. By using a custom service provider or by modifying the service registration in the ConfigureServices() method
b. By configuring the service in web.config
c. By using attributes on the service class
d. By defining a service locator
Answer: a. By using a custom service provider or by modifying the service registration in the ConfigureServices() method
What is the purpose of the ServiceCollectionExtensions class?
a. To provide extension methods for configuring services in the IServiceCollection
b. To handle HTTP requests and responses
c. To configure middleware components
d. To define routing for HTTP requests
Answer: a. To provide extension methods for configuring services in the IServiceCollection