title: Not properly add inputAccessoryView for UITextField
body: <p>There is a requirement of <code>inputAccessoryView</code> is for the chat application.</p>
  
  <p>When I add <code>inputAccessoryView</code> to <code>UITextField</code> on tap event of <code>UIButton</code>. That view is set as <code>inputAccessoryView</code> completely but text field is not becoming first responder.</p>
  
  <p>(Note: Super view of <code>textfield</code> is viewText.)</p>
  
  <pre><code>- (IBAction)btnOpenTextField:(id)sender
  {
      UIView *accessoryView=[[UIView alloc]init];
      accessoryView.frame=CGRectMake(0,0, _viewText.frame.size.width, _viewText.frame.size.height);
      [accessoryView addSubview:_viewText];
  
      _txtMessage.inputAccessoryView = accessoryView;
      [_txtMessage becomeFirstResponder];
  }
  </code></pre>
  
  <p>Thanks in Advance.</p>