iOS限制不允许使用乘数 [英] iOS constraints doesn't allow to use multiplier

问题描述

我正在尝试布局一些自定义视图，并且当我尝试激活约束时，Xcode说我不能使用乘数.这是代码示例:

I am trying to layout some custom views and when I try to activate the constraints, Xcode says that I can't use multiplier. Here is an example of the code:

class MenuView: UIView {

    var addButton: AddButton!
    var settingsButton: SettingsButton!

    // ........

    func setConstraints (withBarReference reference: NSLayoutYAxisAnchor) {
        NSLayoutConstraints.activateConstraints([
             // ........
             addButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 0.5),
             // ........
             settingsButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 1.5)
        ])
    }

}

这里的问题是Xcode给出了contointEqualToAnchor:函数的语法错误，并说我应该将乘数"替换为常量".

The thing here is that Xcode gives a syntax error on the contraintEqualToAnchor: functions and says that I should replace "multiplier" to "constant".

为什么不能在X中心锚点上使用乘数选项?

Why can't I use the multiplier option with the X center anchors?

推荐答案

您不能使用辅助函数来设置乘数，但是可以使用NSLayoutConstraint初始化程序来设置乘数.自己被这个卡住了，但是找到了答案.

You can't set multiplier using helper functions, but you can set multiplier using NSLayoutConstraint initializer. Just got stuck by this myself, but found the answer.

您的代码:addButton.centerXAnchor.constraintEqualToAnchor(self.centerXAnchor, multiplier: 0.5)

正确的代码:NSLayoutConstraint(item: addButton, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 0.5, constant: 0)

此外，不要忘记通过键入isActive = true

Also, don't forget to activate this constraint by typing isActive = true

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