我尝试根据用户在alert中的选择从collectionview中删除项目
我有以下代码
func collectionView(collectionView: UICollectionView,didSelectItemAtIndexPath indexPath: NSIndexPath) {
let person = people[indexPath.item]
let questionController = UIAlertController(title: "What u wanna do?",message: nil,preferredStyle: .Alert)
questionController.addAction(UIAlertAction(title: "Rename person",style: .Default,handler: {
(action:UIAlertAction!) -> Void in
let ac = UIAlertController(title: "Rename person",preferredStyle: .Alert)
ac.addTextFieldWithConfigurationHandler(nil)
ac.addAction(UIAlertAction(title: "Cancel",style: .Cancel,handler: nil))
ac.addAction(UIAlertAction(title: "OK",style: .Default) { [unowned self,ac] _ in
let newName = ac.textFields![0] as! UITextField
person.name = newName.text
self.collectionView.reloadData() })
self.presentViewController(ac,animated: true,completion: nil)
}))
questionController.addAction(UIAlertAction(title: "Delete Person",handler: {
(action:UIAlertAction!) -> Void in
println("hello world")
self.collectionView.deleteItemsAtIndexPaths([indexPath.item])
self.collectionView.reloadData()
}))
presentViewController(questionController,completion: nil)
}
当我按删除人员时,你好世界工作正常和应用程序崩溃
控制台输出是
hello world 2015-07-18 13:40:14.628 Project10[15888:1274436] -[__NSCFNumber section]: unrecognized selector sent to instance 0xb000000000000003 2015-07-18 13:40:14.636 Project10[15888:1274436] *** Terminating app due to uncaught exception 'NSInvalidArgumentException',reason: '-[__NSCFNumber section]: unrecognized selector sent to instance 0xb000000000000003'
我究竟做错了什么 ？
你应该改变
self.collectionView.deleteItemsAtIndexPaths([indexPath.item])
至
self.collectionView.deleteItemsAtIndexPaths([indexPath])
deleteItemsAtIndexPaths需要一个NSIndexPaths数组,而不是数组.
除此之外,如果你调用deleteItemsAtIndexPaths,你不需要调用reloadData – 这甚至可以防止任何动画发生.
不要忘记更新数据源 – 必须从人员阵列中删除此人.
people.removeAtIndex(indexPath.item)
在调用deleteItemsAtIndexPaths之前执行此操作.
