如何将以下代码从 Swift 2 翻译成 Swift 5？

Question

相信下面的代码是写在Swift 2.如何把语法转换成最新的Swift(5)?

当使用 Xcode 进行转换时，它给我留下了如下错误：

Extra argument 'usingEncoding' in call

和

Cannot call value of non-function type 'URLSession'

原件（需要帮助转换）：

let request = NSMutableURLRequest(URL: NSURL(string: "http://www.sample.com/sample.php")!)
        request.HTTPMethod = "POST"

        let postString = "a=\(customerLabel!)"
        request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)

        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
            data, response, error in

            if error != nil {
                print("error=\(error)")
                return
            }

            print("response = \(response)")

            let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
            print("responseString = \(responseString)")
        }
        task.resume()
    }

这是我的尝试，但有错误：

let request = NSMutableURLRequest(url: URL(string: "http://www.sample.com/sample.php")!)
request.httpMethod = "POST"
let postString = "a=\(customerLabel!)"
request.HTTPBody = postString.data(usingEncoding: NSUTF8StringEncoding)

let task = URLSession.sharedSession().dataTaskWithRequest(request) {
    data, response, error in

    if error != nil {
        print("error=\(error)")
        return
    }

    print("response = \(response)")

    let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
    print("responseString = \(responseString)")
}
task.resume()

Answer 1

不要使用 NSMutableURLRequest。使用 URLRequest.
不要使用NSString，使用String。
查看 URLSession 文档，发现您需要 shared，而不是 sharedInstance()。
data(using .utf8).
许多其他修复。

这是您的固定代码，可以更好地处理完成处理程序中的可选值：

var request = URLRequest(url: URL(string: "http://www.sample.com/sample.php")!)
request.httpMethod = "POST"
let postString = "a=\(customerLabel!)"
request.httpBody = postString.data(using: .utf8)

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    if let error = error {
        print("error=\(error)")
        return
    }

    print("response = \(response)")

    if let data = data, let responseString = String(data: data, encoding: .utf8) {
        print("responseString = \(responseString)")
    }
}
task.resume()

如何将以下代码从 Swift 2 翻译成 Swift 5？

How can I translate the following code from Swift 2 to Swift 5?

swift

swift2

swift5