CustomAIFunctions.cs

using System.ComponentModel;
using Microsoft.Extensions.AI;

namespace DXBlazorChatFunctionCalling.Services;
public class CustomAIFunctions
{
    public static AIFunction GetWeatherTool => AIFunctionFactory.Create(GetWeather); 
    [Description("Gets the current weather in the city")]
    public static string GetWeather([Description("The name of the city")] string city)
    {
        switch (city)
        {
            case "Los Angeles":
            case "LA":
                return GetTemperatureValue(20);
            case "London":
                return GetTemperatureValue(15);
            default:
                return $"The information about the weather in {city} is not available.";
        }
    }
    static string GetTemperatureValue(int value)
    {
        var valueInFahrenheits = value * 9 / 5 + 32;
        return $"{valueInFahrenheits}\u00b0F ({value}\u00b0C)";
    }
}