设置leftBarButtonItem垂直位置

Question

我试图给leftBarButtonItem一个最高的利润率，但它不工作。我可以向右移动，但不能向下移动。

self.navigationItem.leftBarButtonItem?.setTitlePositionAdjustment(UIOffsetMake(10, 20), forBarMetrics: UIBarMetrics.Default)

水平参数10确实有效，它会将标题向右移动。但是垂直参数20不会做任何事情，不管我把它改成什么数字。

完整代码：

let attributes = [NSFontAttributeName: UIFont.ioniconOfSize(24)] as Dictionary!
let newBackButton = UIBarButtonItem(title: String.ioniconWithName(Ionicon.ChevronLeft), style: UIBarButtonItemStyle.Plain, target: self, action: "back:")
self.navigationItem.leftBarButtonItem = newBackButton;
self.navigationItem.leftBarButtonItem?.setTitleTextAttributes(attributes, forState: .Normal)
self.navigationItem.leftBarButtonItem?.setBackgroundVerticalPositionAdjustment(5, forBarMetrics: UIBarMetrics.Default)

Answer 1

尝试：

self.navigationItem.leftBarButtonItem?.setBackgroundVerticalPositionAdjustment(5, forBarMetrics: UIBarMetrics.Default)