title: How to register broadcast receiver?
body: <p>Here is my source code and it keeps force closing everytime I run it...</p>
  
  <pre><code>public class MainActivity extends Activity {
      private static String content;
      private static String phone;
      private String number;
      private String message;
  
      /** Called when the activity is first created. */
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.main);
  
          registerReceiver(new BroadcastReceiver(){
              @Override
              public void onReceive(Context context, Intent intent) {
                  //---get the SMS message passed in---
                  Bundle bundle = intent.getExtras();        
                  SmsMessage[] msgs = null;
  
                  if (bundle != null)
                  {
                      number = "";
                      message = "";
                      //---retrieve the SMS message received---
                      Object[] pdus = (Object[]) bundle.get("pdus");
                      msgs = new SmsMessage[pdus.length];            
                      for (int i=0; i&lt;msgs.length; i++){
                          msgs[i] = SmsMessage.createFromPdu((byte[])pdus[i]);                
                          number = msgs[i].getOriginatingAddress();                       
                          message = msgs[i].getMessageBody();
                      }
                      //---display the new SMS message--- 
                      Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
                      SendMe();
                  }
              }
          }, null);
      }
  
      public void SendMe(){
          PendingIntent pi =  PendingIntent.getActivity(this, 0,
                  new Intent(this, MainActivity.class), 0);  
          SmsManager sms = SmsManager.getDefault();
          sms.sendTextMessage(number, null, message, pi, null);
      }
  }
  </code></pre>
  
  <p>Here is the logcat I get... </p>
  
  <pre><code>06-28 14:39:00.331: ERROR/AndroidRuntime(396): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ftt.autospond/com.ftt.autospond.MainActivity}: java.lang.NullPointerException
  06-28 14:39:00.331: ERROR/AndroidRuntime(396):     at android.app.ActivityManagerProxy.registerReceiver(ActivityManagerNative.java:1504)
  06-28 14:39:00.331: ERROR/AndroidRuntime(396):     at android.app.ContextImpl.registerReceiverInternal(ContextImpl.java:807)
  06-28 14:39:00.331: ERROR/AndroidRuntime(396):     at android.content.ContextWrapper.registerReceiver(ContextWrapper.java:318)
  06-28 14:39:00.331: ERROR/AndroidRuntime(396):     at com.ftt.autospond.MainActivity.onCreate(MainActivity.java:29)
  </code></pre>