返回當前連網狀態

 public static String getNetwrokType(Context context) {
  ConnectivityManager connectivityManager = (ConnectivityManager) context
    .getSystemService(Context.CONNECTIVITY_SERVICE);
  NetworkInfo info = connectivityManager.getActiveNetworkInfo();
  if (info != null && info.isAvailable()) {
   if (info.getTypeName().equalsIgnoreCase("wifi")) {
    return "wifi";
   } else if (info.getTypeName() != null
     && info.getTypeName().equalsIgnoreCase("mobile")
     && info.getExtraInfo() != null) {
    if (info.getExtraInfo().equalsIgnoreCase("cmwap")) {
     return "cmwap";
    } else if (info.getExtraInfo().equalsIgnoreCase("cmnet")) {
     return "cmnet";
    }else if (info.getExtraInfo().equalsIgnoreCase("3gnet")) {
    return "3gnet";
    }
   }
  }
  return "";
 }