<pre>

• (void)viewWillAppear:(BOOL)animated{
  [super viewWillAppear:animated];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name:UIKeyboardWillShowNotification object:nil];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidHid) name:UIKeyboardWillHideNotification object:nil];

}

• (void)viewWillDisappear:(BOOL)animated{
  [super viewWillDisappear:animated];
  [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillShowNotification object:nil];
  [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillHideNotification object:nil];
  }

pragma mark - function

• (void)keyboardDidShow:(NSNotification *)notification{
  NSValue *value = [[notification userInfo] valueForKey:UIKeyboardFrameEndUserInfoKey];
  CGRect rect = [value CGRectValue];
  UIView *firstResponder = [self.view.window performSelector:@selector(firstResponder)];
  CGRect tfrect = [firstResponder.superview convertRect:firstResponder.frame toView:self.view.window];
  if (tfrect.origin.y+self.view.frame.origin.y > rect.origin.y + firstResponder.frame.size.height) {
  CGFloat movedistance = tfrect.origin.y - rect.origin.y +firstResponder.frame.size.height;
  self.view.frame.origin.y -= movedistance;
  }
  }

-(void)keyboardDidHid{

 self.view.frame.origin.y = 0;//注意iOS7之后非透明的导航栏设置成64

}

</pre>