Question

我在“收集查看单元格”上使用“单击”来调用performSegue内的collectionView didSelectItemAt。有时特别是当应用程序首次启动时，performSegue会延迟，不确定原因，用户再次点击＆amp;再次。在这种情况下，多次调用performSegue并多次按下新视图控制器（抽头数）。这种延迟的任何特殊原因？如果没有，那么我将不得不实施以下内容：

var alreadyTapped = false
override func viewDidAppear(_ animated: Bool) {
    alreadyTapped = false
}
override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    if alreadyTapped { return }
    alreadyTapped = true
    performSegue(withIdentifier: Constants.Segue.DETAIL_VC, sender: collectionView.cellForItem(at: indexPath))
}

或者，如果有更好的方法来解决这个问题？

Answer 1

尝试以下代码，

  override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        DispatchQueue.main.async {
            performSegue(withIdentifier: Constants.Segue.DETAIL_VC, sender: collectionView.cellForItem(at: indexPath))
        }
    }

Answer 2

您可以做一个布尔标志...但是我更喜欢延迟...

var didSelectTime = Date()

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {

    //MARK:- Prevent multiple calls. If elapsed time between calls is less than 1 sec, do nothing
    if Date().timeIntervalSince(self.didSelectTime) < 1.0 {
        self.didSelectTime = Date()
        return
    }
    self.didSelectTime = Date() 
    .....
}

UICollectionView阻止多次点击/调用didSelectItemAt

2 个答案: