title: Changing Count of ViewPager
body: <p>How do you unlock the ability to slide to a new page after clicking a button on a previous page?</p>
  
  <p>Currently I have a PagerAdapter. The code below instantiates the item. Within the getCount(), a value of 3 is returned and thus 3 slides are made. I was wondering if there was a way to only have 3 views, but after clicking a button, unlock a 4th view that you can now slide to?</p>
  
  <pre><code>@Override
      public Object instantiateItem(final View collection, int position) {
          final LayoutInflater inflater = (LayoutInflater) TViewPager.this
                  .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
          TextView tv = new TextView(TViewPager.this);
  
  //Describe the separate layouts of views
  switch (position) {
          case 1:
              View v1 = inflater.inflate(R.layout.expander2, null, false);
                  ((ViewPager) collection).addView(v1, 0);
                  final Button button = (Button) findViewById(R.id.button_click_me);
                  button.setOnClickListener(new View.OnClickListener() {
                       public void onClick(View v1) {
                           Toast.makeText(getBaseContext(), "+1", Toast.LENGTH_LONG).show();
                          //*Some code*//
  
                       }
                   });
                  return v1;
  </code></pre>
  
  <p>Is there a way to change the:</p>
  
  <pre><code>public int getCount() {
          return 3; 
      }
  </code></pre>
  
  <p>Like a "setCount()" and then place it at the //* some code *// to increase the amount of slides?</p>
  
  <p>Would adding </p>
  
  <pre><code>instantiateItem(collection,4);
  </code></pre>
  
  <p>work somewhere work?</p>
  
  <p>Thanks,</p>