ios 快速的 NSLayoutConstraint
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时间：2020-08-31 02:01:09 来源:igfitidea点击:
NSLayoutConstraint in swift
提问by amau96
I am trying to convert the following code to Swift:
我正在尝试将以下代码转换为 Swift：
leftConstraint = [NSLayoutConstraint constraintWithItem:self.contentView
attribute:NSLayoutAttributeLeft
relatedBy:0
toItem:self.view
attribute:NSLayoutAttributeLeft
multiplier:1.0
constant:0];
[self.view addConstraint:leftConstraint];
Can someone give me the new syntax to do it in Swift?
有人可以给我在 Swift 中执行此操作的新语法吗？
回答by Michael
Copy & paste from the documentation:
从文档中复制和粘贴：
convenience init(item view1: AnyObject!,
attribute attr1: NSLayoutAttribute,
relatedBy relation: NSLayoutRelation,
toItem view2: AnyObject!,
attribute attr2: NSLayoutAttribute,
multiplier multiplier: CGFloat,
constant c: CGFloat)
So your code translates to
所以你的代码翻译成
let leftConstraint = NSLayoutConstraint(item: self.contentView,
attribute: .left,
relatedBy: .equal,
toItem: self.view,
attribute: .left,
multiplier: 1.0,
constant: 0.0);
self.view.addConstraint(leftConstraint);
Code updated for Swift 4.
为 Swift 4 更新了代码。
回答by mt_
Try this:
尝试这个：
var leftConstrains:NSLayoutConstraint = NSLayoutConstraint(item: self.contentView, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: self.contentView, attribute: NSLayoutAttribute.Left, multiplier: 1, constant: 0)
self.contentView.addConstraint(leftConstrains)
