Android determines whether a mobile phone is connected to IOT platform. android is connected to IOT platform.

Android determines whether a mobile phone is connected to IOT platform. android is connected to IOT platform.

I wrote a function to determine whether the mobile phone is connected to the Internet. However, I found that everything works normally when the mobile phone is connected to the Internet, and a crash occurs when the mobile phone is disconnected from the Internet.

First, the first response is whether the network access permission is not set in the AndroidManifest. xml file:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission> 

If this statement is found, where is the error? My initial code is as follows:

/** Determine whether the Network is available * @ param context * @ return */public static boolean isNetworkAvailable (Context context) {ConnectivityManager cm = (ConnectivityManager) context. getSystemService (Context. CONNECTIVITY_SERVICE); return cm. getActiveNetworkInfo (). isAvailable ();}

After debugging, I found that when I disconnected the network, the NetworkInfo instance returned in cm. getActiveNetworkInfo () is a null pointer, and an error occurred when I called isAvailable. Therefore, you must judge the NetworkInfo instance.

    public static boolean isNetworkAvailable(Context context) {       try {ConnectivityManager manger = (ConnectivityManager) context                .getSystemService(Context.CONNECTIVITY_SERVICE);         NetworkInfo info = manger.getActiveNetworkInfo();        //return (info!=null && info.isConnected());//        if(info != null){        return info.isConnected();        }else{        return false;        }} catch (Exception e) {        return false;}    }