UIScrollView不用再写setContentSize了

不用再写了：《《《 [self.myScrollView setContentSize:CGSizeMake(kScreenWidth, CGRectGetMaxY(self.gongWeiLocationCollectionView.frame)+kIPhoneXBottomHeight)];》》》

直接这样：先：

    [self.view addSubview:self.myScrollView];

    [self.myScrollView mas_makeConstraints:^(MASConstraintMaker *make) {

        make.top.equalTo(self.topBarView.mas_bottom).with.offset(kAutoW(0));

        make.width.mas_equalTo (kScreenWidth);

        make.left.right.mas_equalTo(0);

        make.bottom.mas_equalTo(kAutoW(-kIPhoneXBottomHeight));

    }];

然后最后一个添加的ui的 bottom.这样：make.bottom.equalTo(_myScrollView.mas_bottom).with.offset(-20);就可以了

    [_downloadImageView mas_makeConstraints:^(MASConstraintMaker *make) {

        make.centerX.equalTo(self.view);

        //        make.left.equalTo(self.view).with.offset(15);

        //        make.right.equalTo(self.view).with.offset(-15);

         make.top.equalTo(titleLabel.mas_bottom).with.offset(12);

        make.width.mas_offset(downloadImage.size.width);

        make.height.mas_offset(downloadImage.size.height);

 make.bottom.equalTo(_myScrollView.mas_bottom).with.offset(-20);

    }];