title: programming an android app - where to start
body: <p>I have been looking all over the internet and i found some good guides for programing in android but i still dont fully understand what exactly is going on with this thing</p>
  
  <p>i thought this would be like programing a java program but its very different.. there are lots of xml files and there is this thing called "activity" and an "intent" of which i dont understand how they work.. same with the way of displaying things..there is this xml file that designs the way the app looks but when you i used this code:</p>
  
  <pre><code>public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      // Get the message from the intent
      Intent intent = getIntent();
      String message = intent.getStringExtra(FirsttimeActivity.EXTRA_MESSAGE);
  
      // Create the text view
      TextView textView = new TextView(this);
      textView.setTextSize(40);
      textView.setText(message);
  
      setContentView(textView);
  }
  </code></pre>
  
  <p>the text box that was there before disappeared and a normal text appeared instead.. what just happand here? how do i replace the text with something else after that? how do i go back to the normal view? </p>
  
  <p>so my qoustions are as follows:</p>
  
  <p>what does an "activity" mean? whats the parallel in a normal java project?
  whats an intent and how does it work?
  how do i control the display? how come it changed when i entered that code?</p>
  
  <p>thanx</p>