WS(weakSelf);
[self.view addSubview:self.scrollView];
[_scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo(weakSelf.view);
}];
[_scrollView addSubview:self.containerView];
[_containerView mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.equalTo(weakSelf.scrollView);
make.width.equalTo(weakSelf.scrollView);
}];
// 所有的子控件都放到containerView里面, 在最后一个子控件后设置约束
[_containerView mas_makeConstraints:^(MASConstraintMaker *make) {
make.bottom.equalTo(confirmBtn.mas_bottom).offset(20);
}];
