UISearchBar showsCancelButton动画制作完成

Question

我需要知道UISearchBar的cancel按钮在调用后何时完成动画

searchBar.setShowsCancelButton(false, animated: true)

我试过了

UIView.animateWithDuration(3, animations: {
    self.searchBarView.searchBar.showsCancelButton = false
         }, completion: {finished in
         print(finished)
})

但是完成块是立即触发的，任何解决方案都将不胜感激。

Answer 1

您可以使用layoutIfNeeded()在UIView.animateWithDuration(...)中更新视图

尝试以下代码：

import UIKit

class ViewController: UIViewController {

@IBOutlet var searchBar: UISearchBar!

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

@IBAction func touchUpInside(sender: UIButton) {
    searchBar.showsCancelButton = !searchBar.showsCancelButton
    UIView.animateWithDuration(3, animations: {
        self.searchBar.layoutIfNeeded()
        }, completion: {finished in
            print("Animation finished")
    })
}
}

和故事板：

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