天气应用（Swift）如何判断当天是否会下雨，同时获得下一小时的天气预报？

该问题可以通过调用苹果提供的天气API实现。首先需要获取用户的位置信息，即CLLocation，然后使用该信息调用天气API获取当前位置的天气情况。接着，可以使用“hourly”字段获取下一小时的天气预报。最后，检查“Rain”字段是否为真以确定当天是否会下雨。具体示例如下：

import CoreLocation

class WeatherManager {

    static let shared = WeatherManager()

    private let apiKey = "your_api_key"

    private init() {}

    func getWeatherData(for location: CLLocation, completion: @escaping (WeatherData?, Error?) -> Void) {
        let urlString = "https://api.openweathermap.org/data/2.5/onecall?lat=\(location.coordinate.latitude)&lon=\(location.coordinate.longitude)&appid=\(apiKey)&units=metric"
        guard let url = URL(string: urlString) else { return }

        URLSession.shared.dataTask(with: url) { data, _, error in
            if let error = error {
                completion(nil, error)
                return
            }

            guard let data = data else { return }

            do {
                let weatherData = try JSONDecoder().decode(WeatherData.self, from: data)
                completion(weatherData, nil)
            } catch {
                completion(nil, error)
            }
        }.resume()
    }
}

struct WeatherData: Codable {
    let current: Current
    let hourly: [Hourly]
}

struct Current: Codable {
    let rain: Rain?
}

struct Hourly: Codable {
    let dt: Double
    let rain: Rain?
}

struct Rain: Codable {
    let `1h`: Double
}

// Usage:
let locationManager = CLLocationManager()
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()

locationManager.delegate = self

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    guard let location = locations.last else { return }

    WeatherManager.shared.getWeatherData(for: location) { weatherData, error in
        if let error = error {
            print(error.localizedDescription)
            return
        }

        guard let weatherData = weatherData else { return }

        // Check if it will rain today
        if let rain = weatherData.current.rain {
            print("It will rain today! \(rain)")
        } else {
            print("It won't rain today.")
        }

        // Get next hour forecast
        if let nextHour = weatherData.hourly.first,
           let rain = nextHour.rain {
            print("Next hour: \(nextHour.dt). Rain: \(rain)")
        }
    }
}