来自＆＃39; [NSIndexPath]？＆＃39;到[NSIndexPath]＆＃39;只打开选项;你的意思是使用＆＃39;！＆＃39;？

Question

func backBtnAction(){

    var index = collectionView?.indexPathsForSelectedItems() as! [NSIndexPath]
    collectionView?.scrollEnabled = true
    collectionView?.reloadItemsAtIndexPaths(index)
}

如何在indexpath中获取collectionview ...就像我正在做的那样

var index = collectionView?.indexPathsForSelectedItems() as! [NSIndexPath]

Answer 1

indexPathsForSelectedItems()返回[NSIndexPath]?，所以通常的方式是可选绑定而不需要强制转换

func backBtnAction() 
{
   if let indexes = collectionView?.indexPathsForSelectedItems() {
       collectionView!.scrollEnabled = true
       collectionView!.reloadItemsAtIndexPaths(indexes)
   }
}