在学习Android的广播接收器的时候，监听网络变化，告知用户是有网络还是无网络。
在onReceive方法中调用getActiveNetworkInfo()时报错

报错信息：Missing permissions required by ConnectivityManager.getActiveNetworkInfo: android.permission.ACCESS_NETWORK_STATE less... (Ctrl+F1) 
This check scans through your code and libraries and looks at the APIs being used, and checks this against the set of permissions required to access those APIs. If the code using those APIs is called at runtime, then the program will crash.  Furthermore, for permissions that are revocable (with targetSdkVersion 23), client code must also be prepared to handle the calls throwing an exception if the user rejects the request for permission at runtime.  Issue id: MissingPermission

解决办法：
在app/src/main/AndroidManifest.xml里添加权限，如下：
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

其实点击小灯泡也可以自动帮你加