iOS Swift 3 POST issue

Question

我有一些代码，我用了一段时间，运行得很好。 我现在希望在我的新项目中使用它，该项目是 swift 3，虽然我已经修复了大多数错误，但我仍然有两个如下：

以下代码行：var _: NSData? = NSURLConnection.sendSynchronousRequest(request as URLRequest, returning:&response) as NSData产生以下错误：Call can throw, but it is not marked with 'try' and the error is not handled

以下代码行：NSLog("Response code: %ld", res?.statusCode ?? <#default value#>); 生成以下错误：Editor placeholder in source file 。

任何帮助，不胜感激。

以下是可能有助于解决问题的完整代码：

        func webViewDidFinishLoad(_ webView: UIWebView) {
        UIApplication.shared.isNetworkActivityIndicatorVisible = false
        let post:NSString = "userid=349&devicetoken=walan"
        NSLog("PostData: %@",post);
        let url:NSURL = NSURL(string: "https://str8red.com/updateAPN")!
        let postData:NSData = post.data(using: String.Encoding.ascii.rawValue)! as NSData
        let postLength:NSString = String( postData.length ) as NSString
        let request:NSMutableURLRequest = NSMutableURLRequest(url: url as URL)
        request.httpMethod = "POST"
        request.httpBody = postData as Data
        request.setValue(postLength as String, forHTTPHeaderField: "Content-Length")
        request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
        request.setValue("application/json", forHTTPHeaderField: "Accept")

        var _: NSError?
        var response: URLResponse?
        var _: NSData? = NSURLConnection.sendSynchronousRequest(request as URLRequest, returning:&response) as NSData

        let res = response as! HTTPURLResponse!;
        NSLog("Response code: %ld", res?.statusCode ?? <#default value#>);
}

Answer 1

您可以添加try关键字，并用do {} catch {}将语句括起来，如下所示：

do {
 try NSURLConnection.sendSynchronousRequest(request as URLRequest, returning:&response) as NSData
} catch {
    print(error)
}

自iOS 9以来，您仍然会收到有关该功能已弃用的警告。

我将尝试查看如何在iOS 10，Swift 3.1语法中重写整个函数，但是存在它可能会损坏并且看起来与其他遗留代码非常不同的危险。 敬请期待，我会再次更新这个答案。

至于"占位符错误"，您可以输入一些值，例如"500"，默认为"内部服务器错误"

NSLog("Response code: %ld", res?.statusCode ?? 500); 

更新

：这是更新到 Swift 3、iOS 10 的功能。

我只根据函数的原始意图进行更新。只是语法/API更新，没有删除/添加任何功能。

func webViewDidFinishLoad(_ webView: UIWebView) {
    UIApplication.shared.isNetworkActivityIndicatorVisible = false
    let post:String = "userid=349&devicetoken=walan"
    NSLog("PostData: %@",post);
    let url:URL = URL(string: "https://str8red.com/updateAPN")!
    let postData:Data = post.data(using: String.Encoding(rawValue: String.Encoding.ascii.rawValue))!
    let postLength: String = String( postData.count )
    var request:URLRequest = URLRequest(url: url as URL)
    request.httpMethod = "POST"
    request.httpBody = postData as Data
    request.setValue(postLength, forHTTPHeaderField: "Content-Length")
    request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
    request.setValue("application/json", forHTTPHeaderField: "Accept")
    var _: NSError?
    var response: URLResponse?
    URLSession.shared.dataTask(with: request) { (data, res, error) in
        guard error == nil  else {
            print(error!)
            return
        }
        response = res
    }
    let res = response as! HTTPURLResponse!;
    NSLog("Response code: %ld", res?.statusCode ?? 500);   
}