UIStackView我可以使用自动调整大小而不是自动布局的方式添加它

Question

我尝试将UIStackView放置在具有自动调整大小的蒙版.flexibleWidth，.flexibleHeight->的UIScrollView内，即水平/垂直拉伸以填充滚动视图，但是如果将其更改为使用前导/尾随/底部/自动布局的代码，则不会出现堆栈视图顶部约束，然后视图正确显示

toolbar.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        toolbar.backgroundColor = .clear
        toolbar.axis = .horizontal
        toolbar.distribution = .fill
        toolbar.alignment = .fill
        toolbar.spacing = 8


        toolbarScroll.frame = bounds
        toolbarScroll.autoresizingMask = [.flexibleHeight, .flexibleWidth]
        toolbarScroll.showsHorizontalScrollIndicator = false
        toolbarScroll.showsVerticalScrollIndicator = false
        toolbarScroll.backgroundColor = UIColor.green

        toolbarScroll.addSubview(toolbar)

这里是在addSubview之后添加的代码，然后工具栏显示在toolbarScroll中

toolbar.translatesAutoresizingMaskIntoConstraints = false

toolbar.leadingAnchor.constraint(equalTo: toolbarScroll.leadingAnchor).isActive = true
toolbar.trailingAnchor.constraint(equalTo: toolbarScroll.trailingAnchor).isActive = true
 toolbar.bottomAnchor.constraint(equalTo: toolbarScroll.bottomAnchor).isActive = true
 toolbar.topAnchor.constraint(equalTo: toolbarScroll.topAnchor).isActive = true

Answer 1

您在toolbar上添加了toolbarScroll，但没有给它一个框。

toolbarScroll.addSubview(toolbar)

// just to make sure...
toolbar.translatesAutoresizingMaskIntoConstraints = true

// give the toolbar stackView a frame
toolbar.frame = toolbarScroll.bounds