From here you can easily detect the Wifi-Networks as well as there info surrounding your device. This can be achieved by using the "WifiManager" in a following way :-

package com.example.wifidetector;

import java.util.List;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
mport android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

StringBuilder sb = new StringBuilder();
WifiManager mainWifi;
List<ScanResult> wifiList;
WifiReceiver receiverWifi;
Button mainText;
TextView textView;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity&#95;main);

    mainText = (Button) findViewById(R.id.main_text);
    textView = (TextView) findViewById(R.id.text_info);


 mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
            receiverWifi = new WifiReceiver();


registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    mainText.setOnClickListener( new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            mainWifi.startScan();
        }
    });

}

protected void onPause() {
    unregisterReceiver(receiverWifi);
    super.onPause();
}

protected void onResume() {
    registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
    super.onResume();
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}


class WifiReceiver extends BroadcastReceiver {
    @SuppressLint("UseValueOf")
    public void onReceive(Context c, Intent intent) {
        sb = new StringBuilder();
        wifiList = mainWifi.getScanResults();
        for(int i = 0; i < wifiList.size(); i++){
            sb.append(new Integer(i+1).toString() + ".");
            sb.append((wifiList.get(i)).toString());
            sb.append("                                                                     ");

        }
        textView.setText(sb);
    }
 }
}

The layout of this particular activity is simple only contains a button and a text view below it. By doing all this with just a click of a button , the given text view will be set with the information of the available network settings around you.

Don't forget to define the following permission in your Manifest :-

android:name="android.permission.ACCESS_WIFI_STATE"

android:name="android.permission.CHANGE_WIFI_STATE"

Hope this will help you .... :)