Question

如何在swift中获取rightbarbuttonItem的框架？我发现了这个：UIBarButtonItem: How can I find its frame?但它说无法将NSString转换为UIView，或者无法将NSString转换为String：

let str : NSString = "view" //or type String
let theView : UIView = self.navigationItem.rightBarButtonItem!.valueForKey("view")//or 'str'

目标是删除rightBarButtonItem，改为添加imageView，并使用fadeOut效果移动它。

由于

Answer 1

你应该尝试：

var barButtonItem = self.navigationItem.rightBarButtonItem!
var buttonItemView = barButtonItem.valueForKey("view")

var buttonItemSize = buttonItemView?.size

编辑（Swift 3）：

var barButtonItem = self.navigationItem.rightBarButtonItem!
let buttonItemView = barButtonItem.value(forKey: "view") as? UIView
var buttonItemSize = buttonItemView?.size

Answer 2

import UIKit

class ViewController: UIViewController {

    let customButton = UIButton(type: .system)

    override func viewDidLoad() {
        super.viewDidLoad()

        customButton.setImage(UIImage(named: "myImage"), for: .normal)
        self.navigationItem.rightBarButtonItem = UIBarButtonItem(customView: customButton)
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        print(self.customButton.convert(self.customButton.frame, to: nil))
    }
}

您必须使用为customView创建的UIBarButtonItem对象; UIBarButtonItem对象以常规方式创建，没有暴露出足够的信息。在之后查找框架非常重要 父UINavigationController的UINavigationBar已经完全布局了整个子视图树。对于大多数用例，可见的UIViewController viewDidAppear是一个很好的近似。

Answer 3

在Swift4中，XCode9

    for view in (self.navigationController?.navigationBar.subviews)! {
        if let findClass = NSClassFromString("_UINavigationBarContentView") {
            if view.isKind(of: findClass) {
                if let barView = self.navigationItem.rightBarButtonItem?.value(forKey: "view") as? UIView {
                    let barFrame = barView.frame
                    let rect = barView.convert(barFrame, to: view)
                }
            }
        }
    }

在Swift中获取UIBarButtonItem的框架？

3 个答案: