Xcode7 使用NSURLSession发送HTTP请求的问题

Application Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure. Temporary exceptions can be configured via your app's Info.plist file.

解决：

https://developer.apple.com/library/prerelease/ios/releasenotes/General/WhatsNewIniOS/Articles/iOS9.html#//apple_ref/doc/uid/TP40016198-DontLinkElementID_13
在iOS9 beta1中，苹果将原http协议改成了https协议，使用 TLS1.2 SSL加密请求数据。

解决办法：

在info.plist中添加
<key>NSAppTransportSecurity</key><dict>
<key>NSAllowsArbitraryLoads</key>
<true/></dict>