Lab02.md

Lab 02 - Using .NET Core Libraries

Dependency Injection

1. Create a console application
2. Create a service contract IHelloService with a Hello method
3. Create HelloController with constructor injection using the IHelloService, and a Greeting method using the IHelloService
4. Create a concrete imlpementation for the IHelloService
5. Use the HelloController from the Program class
6. Add the NuGet package Microsoft.Extensions.DependendyInjection
7. Register services IHelloService and HelloController with the container
8. Use the HelloController by getting a reference from the container

Questions:

1. How is the HelloController instantiated?
2. What happens if the IHelloService implementation cannot be found?

Configuration

1. Create a console application
2. Add NuGet packages for Microsoft.Extensions.Configuration.
3. Create a configuration builder
4. Create a JSON configuration file to store a connection string
5. Configure the application to invoke it using paramters, e.g. a=42
6. Read the configuration values from the application
7. Add User Secrets to the program, to read user secrets

Questions:

1. How can inner sections be retrieved?
2. Is it possible to get all configured values?
3. What happens if the same value is configured multiple times?
4. What are user secrets good for?

Logging

1. Create a console application
2. Add NuGet packages for "Microsoft.Extensions.Logging.*"
3. Create a logging factory to set up logging, write logs to the console
4. Write log messages from your Main program

Questions:

1. Why another logging framework?
2. Does the logging framework support severity levels?
3. Does the logging framework support scopes?
4. Can logging be configured to use NLog?