我可以通过Swift中的NSURLSession以某种方式执行同步HTTP请求

本文介绍了我可以通过Swift中的NSURLSession以某种方式执行同步HTTP请求的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我可以通过Swift中的 NSURLSession 以某种方式执行同步HTTP请求吗？

Can I somehow do a synchronous HTTP request via NSURLSession in Swift?

我可以执行异步请求通过以下代码：

I can do an asynchronous request via the following code:

if let url = NSURL(string: "2ch.hk/b/threads.json") { let task = NSURLSession.sharedSession().dataTaskWithURL(url) { (data, response, error) in var jsonError: NSError? let jsonDict = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &jsonError) as [String: AnyObject] if jsonError != nil { return } // ... } task.resume() }

但同步请求呢？

提前致谢。

推荐答案

您可以使用此NSURLSession扩展来添加同步方法：

You can use this NSURLSession extension to add a synchronous method:

extension NSURLSession { func synchronousDataTaskWithURL(url: NSURL) -> (NSData?, NSURLResponse?, NSError?) { var data: NSData?, response: NSURLResponse?, error: NSError? let semaphore = dispatch_semaphore_create(0) dataTaskWithURL(url) { data = $0; response = $1; error = $2 dispatch_semaphore_signal(semaphore) }.resume() dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER) return (data, response, error) } }

Swift 3的更新：

extension URLSession { func synchronousDataTask(with url: URL) -> (Data?, URLResponse?, Error?) { var data: Data? var response: URLResponse? var error: Error? let semaphore = DispatchSemaphore(value: 0) let dataTask = self.dataTask(with: url) { data = $0 response = $1 error = $2 semaphore.signal() } dataTask.resume() _ = semaphore.wait(timeout: .distantFuture) return (data, response, error) } }