如何打印出 anchor 常量的值?例如:
let myButton = UIButton()
myButton.topAnchor.constraint(equalTo: view.topAnchor, constant: 5).isActive = true
myButton.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
myButton.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
myButton.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
print(myButton.topAnchor.constant)//this would print 5
最佳答案
常量用于您为 anchor 设置的约束。 anchor 没有有常量。 约束可以。因此,您需要做的是维护约束 的引用并访问常量。
let myButtonTopAnchorConstraint = myButton.topAnchor.constraint(equalTo: view.topAnchor, constant: 5)
myButtonTopAnchorConstraint.isActive = true
myButton.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
myButton.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
myButton.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
print(myButtonTopAnchorConstraint.constant) //Prints 5
一个 View 将只有一个 topAnchor
,但可以有多个相对于该 anchor 的约束。
关于ios - Swift 打印 anchor 常量值,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52772091/