Ios 使用Swift将UILabel动态定位到内容视图的底部?
我试图将动态创建的UILabel定位到contentView的底部。我使用名为Fuzi的HTML解析器捕获HTML标记并基于它们创建UILabelIos 使用Swift将UILabel动态定位到内容视图的底部?,ios,swift,autolayout,swift3,Ios,Swift,Autolayout,Swift3,我试图将动态创建的UILabel定位到contentView的底部。我使用名为Fuzi的HTML解析器捕获HTML标记并基于它们创建UILabel func stringFromHTML( _ string: String?) { do{ let doc = try HTMLDocument(string: string!, encoding: String.Encoding.utf8) if let root = doc.body {
func stringFromHTML( _ string: String?)
{
do{
let doc = try HTMLDocument(string: string!, encoding: String.Encoding.utf8)
if let root = doc.body {
for element in root.children {
if element.tag == "h2" {
// Create new label
let label = UILabel()
label.text = element.stringValue
label.numberOfLines = 0
label.font = UIFont(name: "Avenir Next", size: 17)
label.textColor = UIColor.black
self.contentView.addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
// Label constraints
let labelLeading = NSLayoutConstraint(item: label, attribute: .leading, relatedBy: .equal, toItem: contentView, attribute: .leading, multiplier: 1, constant: 20)
let labelTrailing = NSLayoutConstraint(item: label, attribute: .trailing, relatedBy: .equal, toItem: contentView, attribute: .trailing, multiplier: 1, constant: -20)
let labelTop = NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .top, multiplier: 1, constant: self.contentView.frame.origin.y)
self.contentView.addConstraints([labelLeading, labelTrailing, labelTop])
}
updateContentViewHeight()
}
}
}
catch{
print("html error\n",error)
}
}
func updateContentViewHeight(){
var totalContentHeight:CGFloat = 0.0
for i in self.contentView.subviews {
totalContentHeight += i.frame.height
}
let contentViewHeight:NSLayoutConstraint = NSLayoutConstraint(item: self.contentView, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: totalContentHeight-29)
self.contentView.addConstraint(contentViewHeight)
}
我尝试在ViewDidDisplay中调用stringFromHTML函数。但它将我的UILabels定位在很远的地方(它们似乎并不存在)
我想将标签放置在最后一个标签的底部,请参见下图
有人能帮忙吗?提前谢谢 变化
let labelTop = NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .top, multiplier: 1, constant: self.contentView.frame.origin.y)
到
因为您基本上是在强制每个标签位于相同的y位置。是否要在梯形图样式上添加标签,即在前者的顶部添加后者?@Adeel每次执行循环时,我都要在内容的底部添加标签。例如,在我的HTML中有's和,我将为它们中的每一个创建一个标签,并将它们逐个对齐…我知道您每次遇到
h2
或p
标记时都要添加标签。但我想问一下这些标签的排列/排列。您想水平放置还是垂直放置?如果你能提供你想要的屏幕截图,那会很有帮助。@Adeel:)我能问一下你的问题是什么样子的吗?
if label != nil {
let labelTop = NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: label[index], attribute: .top, multiplier: 1, constant: 2)
} else {
let labelTop = NSLayoutConstraint(item: label, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .top, multiplier: 1, constant: self.contentView.frame.origin.y)
}