<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>

private String getIp(){
  WifiManager wm=(WifiManager)getSystemService(Context.WIFI_SERVICE);
  //检查Wifi状态
  if(!wm.isWifiEnabled())
    wm.setWifiEnabled(true);
  WifiInfo wi=wm.getConnectionInfo();
  //获取32位整型IP地址
  int ipAdd=wi.getIpAddress();
  //把整型地址转换成“*.*.*.*”地址
  String ip=intToIp(ipAdd);
  return ip;
}
private String intToIp(int i) {
  return (i & 0xFF ) + "." +
  ((i >> 8 ) & 0xFF) + "." +
  ((i >> 16 ) & 0xFF) + "." +
  ( i >> 24 & 0xFF) ;
}