session.dataTask 调用错误中的 Swift5 额外参数 'completionHandler'

Question

我正在尝试制作一个天气应用程序但有一些问题错误是“调用中的额外参数 'completionHandler'” 我应该怎么做才能解决它？？ enter image description here

    import Foundation
    
    struct WeatherManager {
        let weatherURL = "http://api.openweathermap.org/data/2.5/weather?APPID=sdfkjskfjsfjskflskflsjklfjf&units=metric"
        
        func fetchWeather(cityName: String) {
           let urlStirng = "\(weatherURL)&q=\(cityName)"
            performRequest(urlString: urlStirng)
        }
        
        func performRequest(urlString: String) {
            //1. Create a URL
            if let url = URL(string: urlString) {
                
                //2. Create a URL Session
                let session = URLSession(configuration: .default)
                
                //3. Give the session a task
                let task = session.dataTask(with: url, completionHandler: handle(data:response:error:))
                
                //4. Start the task
                task.resume()
                
            }
        }
        
        func handle(data: Data?, response: URLSession?, error: Error?) {
            
        }
        
    }

Answer 1

检查以下代码：

func performRequest(urlString: String) {

    //1. Create a URL
    if let url = URL(string: urlString) {
        
        //2. Create a URL Session
        let session = URLSession(configuration: .default)
        
        //3. Give the session a task
        let task = session.dataTask(with: url, completionHandler: handle)
        
        //4. Start the task
        task.resume()
    }
}

func handle(data: Data?, response: URLResponse?, error: Error?) {

}

对于 response 你需要传递一个 URLResponse 而不是 URLSession 到 handle 并且你不必写参数名称，因为你是将您的 handle 函数作为参数传递给 dataTask.

session.dataTask 调用错误中的 Swift5 额外参数 'completionHandler'

Swift5 Extra argument 'completionHandler' in call error with session.dataTask

swift

swift5

completionhandler

urlsession