由于NSURLConnection已在iOS 9中弃用，我尝试将我的代码覆盖到NSURLSession但没有成功。这是我的旧代码：
class Book: NSObject {
var pfBook : PFObject
var coverImage : UIImage!
init(pfBook: PFObject) {
self.pfBook = pfBook
}
func fetchCoverImage(completion: (image: UIImage?, error: NSError?) -> Void) {
let urlString = self.pfBook["s3thumbnailUrl"] as! String
let url = NSURL(string: urlString)
let request = NSURLRequest(URL: url!)
let queue = dispatch_get_main_queue()
NSURLConnection.sendAsynchronousRequest(request, queue: NSOperationQueue.mainQueue()) { (response: NSURLResponse?, data: NSData?, error: NSError?) in
if error == nil {
dispatch_async(dispatch_get_main_queue()){
self.coverImage = UIImage(data: data!)
completion(image: self.coverImage, error: nil)
}
} else {
completion(image: nil, error: error)
}
}
}
}
这是我尝试过的新NSURLSession：
class Book: NSObject {
var pfBook : PFObject
var coverImage : UIImage!
init(pfBook: PFObject) {
self.pfBook = pfBook
}
func fetchCoverImage(completion: (image: UIImage?, error: NSError?) -> Void) {
let urlString = self.pfBook["s3thumbnailUrl"] as! String
let url = NSURL(string: urlString)
let request = NSURLRequest(URL: url!)
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
if error == nil {
dispatch_async(dispatch_get_main_queue()){
self.coverImage = UIImage(data: data!)
completion(image: self.coverImage, error: nil)
}
}else {
completion(image: nil, error: error)
}
})
task.resume()
}
}
当我运行应用程序时，我的调试器只是喷出错误，如下所示：
`2015-09-17 03:05:15.270 MyApp[562:59901] NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9802)
2015-09-17 03:05:15.331 My App[562:59936] This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.
Stack:(
0 CoreFoundation 0x0000000183da4f74 <redacted> + 148
1 libobjc.A.dylib 0x0000000198997f80 objc_exception_throw + 56
2 CoreFoundation 0x0000000183da4ea4 <redacted> + 0
3 Foundation 0x0000000184dbe5d8 <redacted> + 88
4 Foundation 0x0000000184c40a1c <redacted> + 36
5 UIKit 0x00000001893ff958 <redacted> + 64
6 UIKit 0x00000001893ffb9c <redacted> + 548
7 UIKit 0x00000001893ff968 <redacted> + 80
8 UIKit 0x00000001892f62d8 <redacted> + 240
9 UIKit 0x000000018943f35c <redacted> + 640
10 UIKit 0x00000001893fc79c <redacted> + 144
11 UIKit 0x00000001893fc79c <redacted> + 144
12 UIKit 0x00000001893fc6d4 <redacted> + 68
13 UIKit 0x00000001893fc228 <redacted> + 120
14 UIKit 0x00000001893fc194 <redacted> + 280
15 UIKit 0x0000000189400d68 <redacted> + 1048
16 UIKit 0x00000001893fcc3c <redacted> + 244
17 UIKit 0x0000000189b25e8c <redacted> + 460
18 UIKit 0x0000000189b260f4 <redacted> + 200
19 UIKit 0x0000000189b25dbc <redacted> + 252
20 UIKit 0x0000000189b260f4 <redacted> + 200
21 UIKit 0x0000000189b25dbc <redacted> + 252
22 UIKit 0x00000001893ff968 <redacted> + 80
23 UIKit 0x0000000189b260c8 <redacted> + 156
24 UIKit 0x000000018940083c <redacted> + 100
25 UIKit 0x00000001893ff968 <redacted> + 80
26 UIKit 0x0000000189400470 <redacted> + 244
27 UIKit 0x0000000189b2397c <redacted> + 352
28 UIKit 0x0000000189af0f24 <redacted> + 200
29 UIKit 0x0000000189aefdec <redacted> + 72
30 UIKit 0x0000000189aefd88 <redacted> + 48
31 UIKit 0x0000000189ad6cf4 <redacted> + 104
32 UIKit 0x0000000189ad7264 <redacted> + 1108
33 UIKit 0x0000000189ae26f4 <redacted> + 436
34 UIKit 0x00000001894dd6f8 <redacted> + 4108
35 UIKit 0x0000000189ae4128 <redacted> + 132
36 UIKit 0x0000000189309dc0 <redacted> + 80
37 UIKit 0x0000000189ae3830 <redacted> + 2656
38 UIKit 0x0000000189ae1af8 <redacted> + 12448
39 UIKit 0x00000001894d87d8 <redacted> + 364
40 MyApp 0x0000000100101934 _TFFC17MyApp29ThirdCollectionViewController14collectionViewFS0_FTCSo16UICollectionView22cellForItemAtIndexPathCSo11NSIndexPath_CSo20UICollectionViewCellU_FTGSqCSo7UIImage_GSqCSo7NSError__T_ + 316
41 MyApp 0x00000001000b25fc`
`_TFFC17MyApp4Book15fetchCoverImageFS0_FFT5imageGSqCSo7UIImage_5errorGSqCSo7NSError__T_T_U_FTGSqCSo6NSData_GSqCSo13NSURLResponse_GSqS2___T_ + 580
2015-09-17 03:05:15.353 MyApp[562:59936] This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.
我应该调整什么？
答案 0 :(得分：3)
首先，我想提一下几点，
在OS X 10.11和iOS 9.0中不推荐使用NSURLConnection，但是：
不会消失，使用它的应用程序仍然可以使用
新功能将添加到NSURLSession
watchOS不支持
<强>其次，
使用NSURLSession并使用NSURLConnection发送异步调用就像使用NSURLConnection一样简单。
这是发送异步请求的示例代码。希望它有所帮助。
NSURLSession *session = [NSURLSession sharedSession];
[[session dataTaskWithURL:[NSURL URLWithString:londonWeatherUrl]
completionHandler:^(NSData *data,
NSURLResponse *response,
NSError *error) {
// handle response
}] resume];
dataTaskWithURL 旨在取代 NSURLConnection 中的 sendAsynchronousRequest 。
答案 1 :(得分：1)
使用swift3，
$block = $conn->prepare("SELECT `ip` FROM `firewall` WHERE `ip` = :ip");
$block->bindParam(':ip', $_SERVER['REMOTE_ADDR']);
$block->execute();
$block = $block->fetchAll(PDO::FETCH_ASSOC);
if (!empty($block)) {
die("Error!");
}
答案 2 :(得分：0)
下面的功能对我来说很好。
func fetchCoverImage（完成:(图片：UIImage？，错误：NSError？） - ＆gt; Void）{
// let url = NSURL(string: urlString)
var request = NSMutableURLRequest(URL: NSURL(string: "http://www.fnordware.com/superpng/pnggrad16rgb.png")!)
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
if error == nil {
dispatch_async(dispatch_get_main_queue()){
self.coverImage?.image = UIImage(data: data!)
completion(image: self.coverImage?.image, error: nil)
}
}else {
completion(image: nil, error: error)
}
})
task.resume()
}
}
如果您在使用此问题时遇到任何问题，请与我们联系。我只是将网址更改为某个png图片。
答案 3 :(得分：0)
您的代码可能没有任何问题。如果您针对iOS 9 SDK进行编译，NSURLConnection将执行相同的操作。您正在运行App Transport Security限制。在这里阅读：
https://developer.apple.com/library/prerelease/ios/technotes/App-Transport-Security-Technote/
基本上，如果您想要访问没有强加密的网址，您必须修改您的Info.plist文件，告诉iOS让您这样做。