swift - 在 swift 中以编程方式在堆栈视图中添加标签和文本视图
问题描述
我怎样才能有一个标题,然后是几行文本,然后是一个标题,一次又一次地以编程方式限制在视图控制器中间的几行文本?
我的目标是为标题加粗,并且最好让 textview 行也增加。
我的想法是创建 2 个标签和 2 个文本视图。并按以下顺序将它们添加到文本视图:label1、t1、label2、t2。
但这似乎不起作用。我尽量避免多次定义相同的文本视图和标签。如果我复制它的定义两次而不是标签的文本视图加起来(也许它与视图相关?)
我尝试使用 UIbuttons 并且它有效。
这是我到目前为止所尝试的:
import UIKit
class HowToSetupProIGVC: UIViewController {
deinit {print("deinit")}
let textView: UITextView = {
let textView = UITextView()
textView.backgroundColor = .blue //bkgdColor
textView.textAlignment = .left
//textView.frame = CGRect(x: 5, y: 5, width: 5, height: 5)
textView.tintColor = .black
textView.translatesAutoresizingMaskIntoConstraints = false //enable autolayout
textView.heightAnchor.constraint(equalToConstant: 100).isActive = true
textView.widthAnchor.constraint(equalToConstant: 300).isActive = true
return textView
}()
let label: UILabel = {
let l = UILabel(frame:CGRect.zero)
//l.frame = CGRect(x: 5, y: 5, width: 5, height: 5)
l.backgroundColor = .green //bkgdColor
l.font = UIFont.preferredFont(forTextStyle: .headline)
l.translatesAutoresizingMaskIntoConstraints = false //enable autolayout
l.heightAnchor.constraint(equalToConstant: 22).isActive = true
l.widthAnchor.constraint(equalToConstant: 300).isActive = true
return l
}()
override func viewDidLoad() {
super.viewDidLoad()
self.modalUI(arrowButton: false)
self.view.backgroundColor = bkgdColor
customStackHTSProIG ()
}
}
extension HowToSetupProIGVC {
func customStackHTSProIG () {
let label1 = label
let label2 = label
let t1 = textView
let t2 = textView
label1.text = "Title1:"
label2.text = "title2:"
t1.text = """
1. On your profile tap menu
2. Tap settings
3. Tap accounts
4. Tap set up professional account
"""
t2.text = """
1. On your profile tap "Edit profile"
2. Link your created page to your account
"""
//StackView
let stackHTS = UIStackView()
stackHTS.axis = NSLayoutConstraint.Axis.vertical
stackHTS.distribution = .fillEqually
stackHTS.alignment = .center
stackHTS.spacing = 5
stackHTS.backgroundColor = .red
//Add StackView + elements
stackHTS.addArrangedSubview(label1)
stackHTS.addArrangedSubview(t1)
stackHTS.addArrangedSubview(label2)
stackHTS.addArrangedSubview(t2)
self.view.addSubview(stackHTS)
//Constraints StackView
stackHTS.translatesAutoresizingMaskIntoConstraints = false
stackHTS.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
stackHTS.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
//stackHTS.heightAnchor.constraint(equalToConstant: 88).isActive = true
}
}
解决方案
UILabel
&UITextView
都是用 Objective-C 编写的 UIKit 类。它们是引用类型,而不是值类型。
当你写以下 -
let label1 = label
let label2 = label
let t1 = textView
let t2 = textView
两个label1
&label2
都指向一个 & 的相同实例UILabel
。t1
&也是如此t2
。
当你像这样添加它们时 -
//Add StackView + elements
stackHTS.addArrangedSubview(label1)
stackHTS.addArrangedSubview(t1)
stackHTS.addArrangedSubview(label2)
stackHTS.addArrangedSubview(t2)
您希望将 2 个标签和 2 个文本视图添加到 StackView。您只添加了 1 个标签和 1 个 textView。
您希望看到以下所有内容 -
label1.text = "Title1:"
label2.text = "title2:"
t1.text = """
1. On your profile tap menu
2. Tap settings
3. Tap accounts
4. Tap set up professional account
"""
t2.text = """
1. On your profile tap "Edit profile"
2. Link your created page to your account
"""
但是,您只看到以下内容-
label2.text = "title2:"
t2.text = """
1. On your profile tap "Edit profile"
2. Link your created page to your account
"""
解决方案 -
- 创建两个单独的
UITextView
&实例,UILabel
就像您已经为前两个所做的那样,并将这些新实例也添加到堆栈视图中。 - 使用一个
UILabel
并删除其他所有内容。使用NSAttributedString
API 对不同部分/段落的文本进行样式化,并将其分配给UILabel.attributedText
.
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