iOS监听键盘事件

#pragma mark - view life cycle
- (void)viewDidLoad {
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
}#pragma mark - 通知
/**
 *   键盘弹出
 */
- (void)keyboardWillShow:(NSNotification *)note
{

    // 1.取出键盘的高度
    CGRect temp  = [note.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGFloat height = temp.size.height;
    // 2.让工具条向上平移
    // 2.1取出键盘弹出的动画时间
    NSTimeInterval timte = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    [UIView animateWithDuration:timte delay:0 options:7 << 16 animations:^{
        self.bottomBar.transform = CGAffineTransformMakeTranslation(0, -height);
    } completion:nil];

}
/**
 *  键盘隐藏
 */
- (void)keyboardWillHide:(NSNotification *)note
{
    // 2.1取出键盘弹出的动画时间
    NSTimeInterval timte = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];

    // 清空transform
    [UIView animateWithDuration:timte delay:0 options:7 << 16 animations:^{

        self.bottomBar.transform = CGAffineTransformIdentity;
    } completion:nil];

}