ScrollView不设置contentSize属性依然也可以作为底层滚动View（使用masonry设置scrollView的contentSize）

第一步

//下层的scroolView
self.baseScrollView = [[UIScrollView alloc] init];
self.baseScrollView.delegate = self;
self.baseScrollView.frame = CGRectMake(, , SCREEN_WIDTH, SCREEN_HEIGHT);
self.baseScrollView.scrollEnabled = YES;
self.baseScrollView.backgroundColor = [UIColor colorWithHexString:WSFConstants_Color_BackgoundMainColor];
UIGestureRecognizer *gestur = [[UIGestureRecognizer alloc]init];
gestur.delegate = self;
[self.baseScrollView addGestureRecognizer:gestur];
[self.view addSubview: self.baseScrollView];
//contentView
UIView *contentView = [[UIView alloc]init];
[self.baseScrollView addSubview:contentView];
[contentView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.edges.equalTo(self.baseScrollView);
    make.width.equalTo(self.baseScrollView);
}];

第二步

//content
[contentView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.bottom.mas_equalTo(telephoneBtn.mas_bottom).offset();
}];

第三步

<UIScrollViewDelegate>