Swift-如何将一堆视图放入滚动视图中
C目前,我有一个自定义视图(返回一个UITakView),其中包含许多视图(UILabel、UIImageView等)。它可以在高度足够的设备上显示精细的图像 (顺便说一句,这都是通过编程完成的。) 在小屏幕设备上,它将只显示整个视图的顶部。所以我的解决方案是把它放在UIScrollView中。(这应该很简单——但这让我很难过。) 但这根本不会显示,我做错了什么/错过了什么? 部分代码如下:Swift-如何将一堆视图放入滚动视图中,swift,layout,uiscrollview,constraints,uistackview,Swift,Layout,Uiscrollview,Constraints,Uistackview,C目前,我有一个自定义视图(返回一个UITakView),其中包含许多视图(UILabel、UIImageView等)。它可以在高度足够的设备上显示精细的图像 (顺便说一句,这都是通过编程完成的。) 在小屏幕设备上,它将只显示整个视图的顶部。所以我的解决方案是把它放在UIScrollView中。(这应该很简单——但这让我很难过。) 但这根本不会显示,我做错了什么/错过了什么? 部分代码如下: override init(frame: CGRect) { super.init(frame:
override init(frame: CGRect)
{
super.init(frame: frame)
imageFrame.addSubview(prodImage)
NSLayoutConstraint.activate([
prodImage.topAnchor.constraint(equalTo: imageFrame.topAnchor),
prodImage.trailingAnchor.constraint(equalTo: imageFrame.trailingAnchor),
prodImage.leadingAnchor.constraint(equalTo: imageFrame.leadingAnchor),
prodImage.bottomAnchor.constraint(equalTo: imageFrame.bottomAnchor),
])
imageView.addSubview(imageFrame)
NSLayoutConstraint.activate([
imageFrame.topAnchor.constraint(equalTo: imageView.topAnchor),
imageFrame.trailingAnchor.constraint(equalTo: imageView.trailingAnchor),
imageFrame.leadingAnchor.constraint(equalTo: imageView.leadingAnchor),
imageFrame.bottomAnchor.constraint(equalTo: imageView.bottomAnchor),
])
//更多视图
let stack = UIStackView(arrangedSubviews: [imageView, prodName, prodPrice])
stack.axis = .vertical
stack.spacing = (self.frame.height > 400) ? (self.frame.height > 800) ? 15 : 10 : 5
stack.distribution = UIStackViewDistribution.fill
self.addSubview(stack)
NSLayoutConstraint.activate([
stack.leadingAnchor.constraint(equalTo: self.leadingAnchor),
stack.topAnchor.constraint(equalTo: self.topAnchor),
// stack.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -50),
stack.widthAnchor.constraint(equalTo: self.widthAnchor),
])
}
为了进行更改,我替换了下面的小节:
如您所见,我尝试禁用滚动视图的自动约束以使其适合其父视图。。。所有的尝试都失败了
如何使此滚动视图可见?可能的错误:
- 您正在将堆栈视图的前导/尾随设置为滚动视图
- 如果打印帧的宽度,您可能会理解宽度为零
- 无法根据滚动视图确定堆栈视图的宽度
- 滚动视图是一种特殊视图,因为它的内容可以比滚动视图大
- 因此,需要显式设置内容视图(堆栈视图)的宽度
视图
上设置它,而不是基于滚动视图
进行设置(假设将滚动视图添加为viewController视图的子视图)
可能的解决方案2:
可以显式设置堆栈视图的宽度定位
例子:
下面给出了一个简单的示例,说明如何将堆栈视图与滚动视图结合使用
你的大致想法是正确的
- 滚动视图有一个堆栈视图
- 堆栈视图有几个子视图
- 滚动视图很特别,因为滚动视图的内容可以比滚动视图本身更宽、更高(允许滚动)
- 因此,内容的宽度和高度不应与滚动视图绑定
- 设置内容的宽度和高度时,滚动视图不应扮演任何角色
- 正如您所指出的,我喜欢使用滚动视图和内容视图
- 将实际内容添加到堆栈视图,并让堆栈视图增长
- 因此,只要堆栈视图对滚动视图的约束设置正确,事情就应该就绪
- 始终在
中打印帧值,以查看是否符合您的期望viewdide
很好的解释!你说的很有道理。我的主要区别是,我正在实现一个从UIView继承的自定义视图-因此我不能使用
视图
,而是使用self
。我替换了您在可能的修复1中提到的约束,但它会导致崩溃。如果它崩溃,请查看它为什么崩溃,通常崩溃会告诉您它们为什么崩溃。是否因为添加到约束的视图不是视图层次结构的一部分?最好让父视图/容器视图确定其子视图的位置。每个子视图都可以设置其自身的约束,但不要让它知道其父视图
// self.addSubview(stack)
// NSLayoutConstraint.activate([
// stack.leadingAnchor.constraint(equalTo: self.leadingAnchor),
// stack.topAnchor.constraint(equalTo: self.topAnchor),
//// stack.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -50),
// stack.widthAnchor.constraint(equalTo: self.widthAnchor),
// ])
let scrollView = UIScrollView()
// scrollView.translatesAutoresizingMaskIntoConstraints = false
scrollView.addSubview(stack)
NSLayoutConstraint.activate([
stack.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
stack.topAnchor.constraint(equalTo: scrollView.topAnchor),
stack.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor, constant: -50),
stack.widthAnchor.constraint(equalTo: scrollView.widthAnchor),
])
self.addSubview(scrollView)
NSLayoutConstraint.activate([
scrollView.leadingAnchor.constraint(equalTo: self.leadingAnchor),
scrollView.topAnchor.constraint(equalTo: self.topAnchor),
scrollView.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -50),
scrollView.widthAnchor.constraint(equalTo: self.widthAnchor),
])
stack.leadingAnchor.constraint(equalTo: view.leadingAnchor),
stack.topAnchor.constraint(equalTo: view.topAnchor),
class ViewController: UIViewController {
let scrollView = UIScrollView()
let contentView = UIStackView()
let redView = UIView()
let greenView = UIView()
let yellowView = UIView()
override func viewDidLoad() {
super.viewDidLoad()
setupScrollView()
setupContentView()
setupRedView()
setupGreenView()
setupYellowView()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print("scroll view = \(scrollView.frame)")
print("content view = \(contentView.frame)")
print("red view = \(redView.frame)")
print("green view = \(greenView.frame)")
print("yellow view = \(yellowView.frame)")
}
private func setupScrollView() {
scrollView.backgroundColor = .darkGray
view.addSubview(scrollView)
scrollView.translatesAutoresizingMaskIntoConstraints = false
scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
scrollView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
private func setupContentView() {
contentView.axis = .vertical
contentView.distribution = .fill
contentView.alignment = .fill
scrollView.addSubview(contentView)
contentView.translatesAutoresizingMaskIntoConstraints = false
//Strategy is:
//content view's leading / trailing anchors are set to view controller's view
//content view's top / bottom anchors are set to scroll view
contentView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
contentView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
contentView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
}
private func setupRedView() {
redView.backgroundColor = .red
redView.heightAnchor.constraint(equalToConstant: 400).isActive = true
contentView.addArrangedSubview(redView)
}
private func setupGreenView() {
greenView.backgroundColor = .green
greenView.heightAnchor.constraint(equalToConstant: 400).isActive = true
contentView.addArrangedSubview(greenView)
}
private func setupYellowView() {
yellowView.backgroundColor = .yellow
yellowView.heightAnchor.constraint(equalToConstant: 400).isActive = true
contentView.addArrangedSubview(yellowView)
}
}