获取键盘高度

• (void)registerForKeyboardNotifications
  { //使用NSNotificationCenter 键盘出现时
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardDidShowNotification object:nil];
  //使用NSNotificationCenter 键盘隐藏时
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
  }
  //当键盘出现或改变时调用
• (void)keyboardWillShow:(NSNotification *)aNotification
  { //获取键盘的高度
  NSDictionary *userInfo = [aNotification userInfo];
  NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
  CGRect keyboardRect = [aValue CGRectValue];
  int height = keyboardRect.size.height;
  NSLog(@”键盘高度%d”,height);
  [UIView animateWithDuration:0.5 animations:^{
  CGRect subtab = subTable.frame;
  subtab.size.height-=height;
  subTable.frame = subtab;
  } completion:^(BOOL finished) {
  NSLog(@”执行动画完毕”);
  }];
  }
  //当键退出时调用
• (void)keyboardWillHide:(NSNotification *)aNotification
  { //获取键盘的高度
  NSDictionary *userInfo = [aNotification userInfo];
  NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
  CGRect keyboardRect = [aValue CGRectValue];
  int height = keyboardRect.size.height;
  NSLog(@”键盘高度%d”,height);
  CGRect subtab = subTable.frame;
  subtab.size.height+=height;
  subTable.frame = subtab;
  }