title: inputAccessoryView doesn't appear automatically after call "reloadInputViews"
body: <p>First I subclass UIView named MyTextEditorView for overwrite it's inputAccessoryView as readwrite property.</p>
  
  <p>@property (retain, readwrite) UIView *inputAccessoryView;</p>
  
  <p>And I initial UIInputView as display view,then add one UIView as subview; </p>
  
  <pre><code>UIInputVIew *myInputAccessoryView = [[UIInputView alloc] initWithFrame:CGRectMake(0,0,screenWidth,44)];
  
  [myInputAccessoryView addSubview:myDisplayView];
  
  [self setInputAccessoryView:myInputAccessoryView];
  
  [self reloadInputViews];
  </code></pre>
  
  <p>And I have overriden canBecomeFirstResponder for return YES；</p>
  
  <pre><code>- （BOOL）canBecomeFirstResponder
  {
       return YES;
  }
  </code></pre>
  
  <p>When I first initial MyTextEditorView in my viewController1 and make it become first responder,then inputAccessoryView automatically appear.But when I push another viewController2 from this viewController1 and back to viewController1 ,inputAccessoryView will not automatically appear after make it become first responder.</p>
  
  <p>However,when I add some code as following:</p>
  
  <pre><code>    UIInputVIew *myInputAccessoryView = [[UIInputView alloc]  initWithFrame:CGRectMake(0,0,screenWidth,44)];
  
  [myInputAccessoryView addSubview:myDisplayView];
  
  [self setInputAccessoryView:myInputAccessoryView];
  
  [self resignFirstResponder];
  
  [self reloadInputViews];
  
  [self becomeFirstResponder];
  </code></pre>
  
  <p>After then, this inputAccessoryView can automatically appear in any case.But this confused me and anyone can help me raise why the inputAccessoryView can't appear automatically?Thanks in advance!!!</p>