更新Xcode7以后运行模拟器,控制台打印：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.
iOS9引入了新特性App Transport Security (ATS)。详情：App Transport Security (ATS)
新特性要求App内访问的网络必须使用HTTPS协议
解决办法如下:在info.plist里添加如下字段:
NSAppTransportSecurity Dictionary
NSAllowsArbitraryLoads Boolean
