UIBarButtonItem flexibleSpace不工作

Question

在iOS 11中，UIBarButtonSystemItem.flexibleSpace不能工作。

我的源代码：

let backupBtn = UIBarButtonItem(image: UIImage(named: "itemRate.png"),
                                    style: UIBarButtonItemStyle.plain,
                                    target: self,
                                    action: #selector(goToBackup))

let sortBtn = UIBarButtonItem(image: UIImage(named: "itemSize.png"),
                                  style: UIBarButtonItemStyle.plain,
                                  target: self,
                                  action: #selector(changeSort))

let sizeBtn = UIBarButtonItem(image: UIImage(named: "itemSize.png"),
                                  style: UIBarButtonItemStyle.plain,
                                  target: self,
                                  action: #selector(changeSize))

let space = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace,
                                target: nil,
                                action: nil)

self.navigationItem.setRightBarButtonItems([sizeBtn, space, sortBtn, space, backupBtn], animated: true)

如果我使用：

• self.navigationItem.setRightBarButtonItems
• self.navigationItem.setLeftBarButtonItems

按钮出现在左侧或右侧，但始终在一起！

Answer 1

这个蹩脚的解决方案！

您可以根据需要在左侧或右侧使用此解决方案：

let space = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.fixedSpace, target: nil, action: nil)

space.width = (self.view.frame.size.width/2) - (40*UIScreen.main.scale)

self.navigationItem.leftBarButtonItem = backupBtn

self.navigationItem.rightBarButtonItems = [sortBtn, space, sizeBtn]

恐怖，我知道！