title: Why is becomeFirstResponder not working?
body: <p>I added a modal using <a href="https://github.com/hfossli/AGWindowView"><code>AGWindowView</code></a>. Inside the modal view (built using IB), there is a textfield. The textfield has been connected to an outlet.</p>
  
  <p><strong>This doesn't work:</strong></p>
  
  <pre><code>- (void)viewDidAppear:(BOOL)animated
  {
      [super viewDidAppear:animated];
      [self.placesTextField becomeFirstResponder];
  }
  </code></pre>
  
  <p>The call to <code>becomeFirstResponder</code> doesn't work and the keyboard doesn't show up.</p>
  
  <p><strong>This works:</strong></p>
  
  <pre><code>- (void)viewDidAppear:(BOOL)animated
  {
      [super viewDidAppear:animated];
      [self.placesTextField performSelector:@selector(becomeFirstResponder) withObject:nil afterDelay:0];
  }
  </code></pre>
  
  <p>However, if I manually send a message using <code>performSelector:withObject:afterDelay</code> it works. Why is this method not being determined until runtime?</p>