Creating a service to fetch the weather data

To make it easier to change the external weather service and to make the code more testable, we will create an interface for the service. Here's how we go about it:

1. In the Weather project, create a new folder called Services.
2. Create a new public interface called IWeatherService.
3. Add a method for fetching data based on the location of the user, as shown in the following code. Name the method GetForecast:

 public interface IWeatherService
 {
      Task<Forecast> GetForecast(double latitude, double longitude);
 }

When we have an interface, we can create an implementation for it, as follows:

1. In the Services folder, create a new class called OpenWeatherMapWeatherService.
2. Implement the interface and add the async keyword to the GetForecast method.
3. The code should look as follows:

using System;
using System.Globalization;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
using Newtonsoft.Json;
using...