[UIView animateWithDuration:0.1 animations:^{ [self.tipImage mas_updateConstraints:^(MASConstraintMaker *make) { make.bottom.equalTo(popView.mas_bottom).offset(-(kRatio(54)+BottomHeight)); }]; [self.view layoutIfNeeded];/// 一定调用 控件的父view layoutIfNeeded } completion:^(BOOL finished) { }];