title: registerReceiver returns null for SCAN_RESULTS_AVAILABLE_ACTION
body: <p>I'm trying to get the available Wifi list.</p>
  
  <p>I have a separate class that holds the receiver.</p>
  
  <pre><code>public  BroadcastReceiver WifiScanBroadcast = new BroadcastReceiver(){
      public void onReceive(Context context, android.content.Intent intent) 
      {
          results = wifiManager.getScanResults();
          size = results.size();
      };
  </code></pre>
  
  <p>I have instantiated the class with the variable wifiManager.
  Thats the onCreate function of my Activity:</p>
  
  <pre><code>public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_wifi_list);
      wifiManager = new WifiApManager(this);
  
      Intent i = registerReceiver(wifiManager.WifiScanBroadcast, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
  
  
  }
  </code></pre>
  
  <p>This is what i use in the manifest:</p>
  
  <pre><code>&lt;uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /&gt;
  &lt;uses-permission android:name="android.permission.CHANGE_WIFI_STATE" /&gt;
  </code></pre>
  
  <p>When I'm getting to the registerReceiver, it returns Null.
  What is wrong?</p>