swift - 更改UIProgressView的位置？

我在屏幕上添加了进度条。我希望它在容器中水平居中，但我想将其移动到屏幕底部。如何编辑第三行以更改其位置？

func addControls() {
    progressView = UIProgressView(progressViewStyle: UIProgressViewStyle.Default)
    progressView?.center = self.view.center
    view.addSubview(progressView!)
}

最佳答案

您可以使用NSLayoutConstraints并执行类似的操作。第三行是您将进度条放在另一个对象之上或之下的位置。

    var otherObject = UIView()
    self.view.addSubview(progressView)
    let topConstraint = NSLayoutConstraint(item: progressView, attribute: .topMargin, relatedBy: .equal, toItem: otherObject, attribute: .bottomMargin, multiplier: 1, constant: 0)
    let leftConstraint = NSLayoutConstraint(item: progressView, attribute: .leftMargin, relatedBy: .equal, toItem: self.view, attribute: .leftMargin, multiplier: 1, constant: 0)
    let rightConstraint = NSLayoutConstraint(item: progressView, attribute: .rightMargin, relatedBy: .equal, toItem: self.view, attribute: .rightMargin, multiplier: 1, constant: 0)
    let bottomConstraint = NSLayoutConstraint(item: progressView, attribute: .bottomMargin, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 50)
    self.view.addConstraints([topConstraint, leftConstraint, rightConstraint, bottomConstraint])

关于swift - 更改UIProgressView的位置？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/51902363/