Android獲取本地IP地址 .

首先說明，這個是察看WIFI的IP地址的方法，還需要添加User Permission(android.permission.ACCESS_WIFI_STATE)：

    private String getlocalip(){  
            WifiManager wifiManager = (WifiManager)getSystemService(Context.WIFI_SERVICE);    
            WifiInfo wifiInfo = wifiManager.getConnectionInfo();    
            int ipAddress = wifiInfo.getIpAddress();   
            Log.d(Tag, "int ip "+ipAddress);  
            if(ipAddress==0)return null;  
            return ((ipAddress & 0xff)+"."+(ipAddress>>8 & 0xff)+"."  
                    +(ipAddress>>16 & 0xff)+"."+(ipAddress>>24 & 0xff));  
        }  

在這里，我們可以是察看WifiInfo中的信息即WifiInfo.getIpAddress()，將返回一個int型的IP地址，我們可以看看源代碼：

    public int getIpAddress() {  
            if (mIpAddress == null || mIpAddress instanceof Inet6Address) return 0;  
           return NetworkUtils.inetAddressToInt(mIpAddress);  
        }  

    public static int inetAddressToInt(InetAddress inetAddr)  
             throws IllegalArgumentException {  
        byte [] addr = inetAddr.getAddress();  
        if (addr.length != 4) {  
        throw new IllegalArgumentException("Not an IPv4 address");}  
        return ((addr[3] & 0xff) << 24) | ((addr[2] & 0xff) << 16) |  
              ((addr[1] & 0xff) << 8) | (addr[0] & 0xff);  

return ((ipAddress & 0xff)+"."+(ipAddress>>8 & 0xff)+"."  
                +(ipAddress>>16 & 0xff)+"."+(ipAddress>>24 & 0xff));