如果手机连接的是wifi,获取到是192.168.1.1这种格式的地址，
如果连接的是移动网络，获取到的是10.109.51.213这种格式。
public String getHostIP() { String hostIp = null; try { Enumeration nis = NetworkInterface.getNetworkInterfaces(); InetAddress ia = null; while (nis.hasMoreElements()) { NetworkInterface ni = (NetworkInterface) nis.nextElement(); Enumeration<InetAddress> ias = ni.getInetAddresses(); while (ias.hasMoreElements()) { ia = ias.nextElement(); if (ia instanceof Inet6Address) { continue;// skip ipv6 } String ip = ia.getHostAddress(); if (!"127.0.0.1".equals(ip)) { hostIp = ia.getHostAddress(); break; } } } } catch (SocketException e) { Log.i("yao", "SocketException"); e.printStackTrace(); } return hostIp; } 没有联网时，返回“null”
