ios - UIBarButtonItem 的空间问题

Question

我正在尝试使用以下代码将 Cancel UIBarButtonItem 添加到我的导航栏:

func setupNavBar() {
    self.navBar = UINavigationBar(frame: CGRectMake(0.0, 0.0, UIScreen.mainScreen().bounds.width, 64.0))

    let customNavigationItem = UINavigationItem(title: "Connect Accounts")
    let cancelButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Cancel, target: self, action: "cancelClicked")
    customNavigationItem.setLeftBarButtonItem(cancelButton, animated: true)

    self.navBar.setItems([customNavigationItem], animated: true)

    self.view.addSubview(self.navBar)
}

条形按钮完全粘在屏幕边缘，如下所示:

为什么这个按钮看起来粘在屏幕边缘，我怎样才能给它留出间距，这样它就不会粘在那里？请帮忙!

编辑:我的按钮粘在屏幕的左边缘而不是左上角。

Answer 1

添加空间的正确方法是使用 .FixedSpace :

let fixedSpace = UIBarButtonItem(barButtonSystemItem: .FixedSpace, target: nil, action: nil)
fixedSpace.width = 10
customNavigationItem.leftBarButtonItems = [fixedSpace, cancelButton]

UIBarButtonSystemItemFixedSpace

Blank space to add between other items. Only the width property is used when this value is set.

Available in iOS 2.0 and later.