工具類——網絡是否可用

public class NetworkAvailable {
    public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager connectivity = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity != null) {
            NetworkInfo info = connectivity.getActiveNetworkInfo();
            if (info != null && info.isConnected())
            {
                // 當前網絡是連接的
                if (info.getState() == NetworkInfo.State.CONNECTED)
                {
                    // 當前所連接的網絡可用
                    return true;
                }
            }
        }
        return false;
    }
}