swift - 停止 urlRequest onViewDisappear

Question

我按如下方式从我的服务器加载我的 json 信息，但是当我过早地点击离开到另一个页面时，请求一直在后台尝试，并且有一条警告说再也找不到 viewController 了。如何取消所有 onViewDisappear 请求？

if let requestURL = URL(string: "https://www.example.com/file.php") {

        var urlRequest = URLRequest(url: requestURL)
        urlRequest.httpMethod = "POST"
        let postString = "email=\(loginUsername.text!)"
        urlRequest.httpBody = postString.data(using: .utf8)

        let session = URLSession.shared
        let task = session.dataTask(with: urlRequest as URLRequest) {  (data, response, error) in

            if let data = data {
                do {
                    if let jsonResult = try JSONSerialization.jsonObject(with: data, options: []) as? [String:Any] {

                        // Async Stuff
                        DispatchQueue.main.async{

                            // do things
                        }

                        DispatchQueue.main.async(execute: {
                        })
                    }
                } catch {
                    print("Error: \(error)")
                }
            }
        }
        task.resume()
    }

Answer 1

将您的请求保存在某处，然后离开 Controller 调用:

task.cancel()