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

public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main); 
        
        //獲取wifi服務 
        WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); 
        //判斷wifi是否開啟 
        if (!wifiManager.isWifiEnabled()) { 
        wifiManager.setWifiEnabled(true);   
        } 
        WifiInfo wifiInfo = wifiManager.getConnectionInfo();      
        int ipAddress = wifiInfo.getIpAddress();  
        String ip = intToIp(ipAddress);  
        EditText et = (EditText)findViewById(R.id.EditText01); 
        et.setText(ip); 
    }    
    private String intToIp(int i) {      
        
          return (i & 0xFF ) + "." +      
        ((i >> 8 ) & 0xFF) + "." +      
        ((i >> 16 ) & 0xFF) + "." +      
        ( i >> 24 & 0xFF) ; 
     }  

<uses-permission android:name="android.permission.INTERNET"></uses-permission> 

public String getLocalIpAddress() 
    { 
        try 
        { 
            for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) 
            { 
               NetworkInterface intf = en.nextElement(); 
               for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) 
               { 
                   InetAddress inetAddress = enumIpAddr.nextElement(); 
                   if (!inetAddress.isLoopbackAddress()) 
                   { 
                       return inetAddress.getHostAddress().toString(); 
                   } 
               } 
           } 
        } 
        catch (SocketException ex) 
        { 
            Log.e("WifiPreference IpAddress", ex.toString()); 
        } 
        return null; 
    }