ios - 从collectionView中获取indexpath，有时会获取错误的indexPath

Question

在UItableView中，我们可以使用这些代码从UITableView获取indexPath

extension UIView{  
  func getButtonIndexPath(tableView:UITableView) -> NSIndexPath{
            let buttonOriginInTableView = self.convertPoint(CGPointZero, toView: tableView)
            return tableView.indexPathForRowAtPoint(buttonOriginInTableView)!
        }
}

但它在 UICollectionView 中效果不太好

extension UIView{
    func getIndexPath(uc:UICollectionView) -> NSIndexPath?{
        let senderP = CGPointMake(0, self.frame.height / 2)
            let point : CGPoint = self.convertPoint(senderP, toView:uc)
            let ind = uc.indexPathForItemAtPoint(point)
            print("what i click is", point, ind)
        return ind
}

我把它放在UICollectionView中单元格的按钮中

delBtn.addTarget(self, action: #selector(FavViewController.DelFavAction(_:)), forControlEvents: .TouchUpInside)

函数是

    func DelFavAction(sender:UIButton){
    guard let indexPath = sender.getIndexPath(self.collectionView) else {
    return
    }
    print(indexPath)
}

但大多数情况下都会得到错误的indexPath.item，这是怎么发生的？

与此代码有关吗？

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    return rectArr[indexPath.item].size
}

Answer 1

你要写这行:

delBtn.addTarget(self, action: #selector(FavViewController.DelFavAction(_:)), forControlEvents: .TouchUpInside)

下面写下其他行:

delBtn.tag = indexPath.item;

并获取项目:

func DelFavAction(sender:UIButton){
//        sender.tag to convert uibutton;
//  for objectvie C write: UIButton *btn = (UIButton *)sender;
}