Question

我有一个UICollectionView，我在UICollectionView的单元格中处理Long Press，但我不知道哪个单元格被按下了。我试图在didSelectItemAtIndexPath中捕获单元格indexPath但是没有工作。任何人都可以帮助我？谢谢！

这是我正在处理LongPress的方法

@IBAction func handleLongPress(sender: AnyObject) {

    let appDelegate:AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
    let context = appDelegate.managedObjectContext!

    //here I want to get the item to delete

   // var itemToDelete =
    //context.deleteObject(itemToDelete)
    //context.save(nil)

    if sender.state == UIGestureRecognizerState.Began {

        let alertController = UIAlertController(title: nil, message: "My message", preferredStyle: UIAlertControllerStyle.Alert)

        alertController.addAction(UIAlertAction(title: "YES", style: .Default, handler: { (action: UIAlertAction!) in
            self.numberOfCells = self.numberOfCells - 1
            self.myCollectionView.reloadData()

        }))

        alertController.addAction(UIAlertAction(title: "NO", style: .Default, handler: nil))

        presentViewController(alertController, animated: true, completion: {
            println("completion")
        })
    }
}

Answer 1

您可以使用其view属性获取手势识别器操作方法中长按的单元格。然后，您可以使用该视图通过集合视图方法indexPath获取indexPathForCell:。

Answer 2

这里没有足够的信息来回答你的问题。

在我的回答中，我假设每个单元格都有自己的UILongPressGestureRecognizer。

@IBAction func cellLongPressWithRecognizer(recognizer: UILongPressGestureRecognizer)
{
    assert(recognizer.view is UICollectionViewCell)
    let cell = recognizer.view as UICollectionViewCell
    // Yay, you have the cell!

    if let indexPathFromCell = self.collectionView.indexPathForCell(cell) {
        // Yay, you have the index path from the cell
    }

    …
}

如果由于某种原因，您没有将recognizer.view设置为单元格，您仍然可以使其工作。

@IBAction func cellLongPressWithRecognizer(recognizer: UILongPressGestureRecognizer)
{
    let point = recognizer.locationInView(self.collectionView)
    if let indexPathFormPoint = self.collectionView.indexPathForItemAtPoint(point) {
        // Yay, you have the index path from the touch point
    }

    …
}

如何在uiLongPressGestureRecognizer中按下对象

2 个答案: