异常日志：

2018-01-04 15:33:42.270 01NSURLConnection[532:15138] App 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.
2018-01-04 15:33:42.276 01NSURLConnection[532:14992] 连接错误 Error Domain=NSURLErrorDomain Code=-1022 "The resource could not be loaded because the App Transport Security policy requires the use of a secure connection." UserInfo={NSErrorFailingURLStringKey=http://www.baidu.com, NSErrorFailingURLKey=http://www.baidu.com, NSLocalizedDescription=The resource could not be loaded because the App Transport Security policy requires the use of a secure connection., NSUnderlyingError=0x78e21290 {Error Domain=kCFErrorDomainCFNetwork Code=-1022 "The resource could not be loaded because the App Transport Security policy requires the use of a secure connection." UserInfo={NSErrorFailingURLKey=http://www.baidu.com/, NSErrorFailingURLStringKey=http://www.baidu.com/, NSLocalizedDescription=The resource could not be loaded because the App Transport Security policy requires the use of a secure connection.}}}

解决方法:

1. 在项目的根目录下找到Info.plist, 右键->Open As->Source code

   
   
   图1.png

2. 在dict节点下加入如下代码:

    <key>NSAppTransportSecurity</key>
    <dict>
        <key>NSAllowsArbitraryLoads</key>
        <true/>
    </dict>

1. 保存后即可正常访问Http请求

注意： iOS在访问Http请求时会出现这种问题，所以在创建项目时先加入此段代码。由于这段代码经常使用，故可加入代码段中，加入代码段时，去掉第一个尖括号，这样可以省去每次删除一个尖括号的操作。