Updating data source after animating cell removal from UITableView - ios

Question

I have a button in my custom cell that deletes the cell.
So i have a delegate that removes it.
code in view controller:
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("swipeTableViewCell", forIndexPath: indexPath) as! swipeTableViewCell
cell.initCell(self, indexPath: indexPath, text: data[indexPath.row])
return cell
}
delegate method:
func removeCell(indexPath: NSIndexPath){
data.removeAtIndex(indexPath.row)
table.beginUpdates()
table.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
table.endUpdates()
}
code in cell:
func initCell(handler: handleCells, indexPath: NSIndexPath, text: String) {
self.handler = handler
self.indexPath = indexPath
}
button pressed:
#IBAction func OnDelButtonClickListener(sender: UIButton) {
self.handler.removeCell(indexPath)
}
This removes the cell with animation but the reloadData is not called and then the cells have the wrong indexPath.
So when I press a second cells delete the wrong cell gets removed.
If I call reloadData after table.endUpdates() there is no animation.
if I call
let indexSet = NSIndexSet(index: indexPath.section)
self.table.reloadSections(indexSet, withRowAnimation: UITableViewRowAnimation.Automatic)
instead of
table.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
I don't get a removal animation.
Any suggestions?
Thanks

Answer 1

Have a look at Apple's programming guide for UITableViews, at the row deleting section.
I may be missing something in your code, but it looks like you don't actually delete the object in the datasource that corresponds to your deleted cell. Try removing the object from your datasource in the removeCell function before you delete the row.
func removeCell(indexPath: NSIndexPath){
// here you delete the object form the datasource
// after that, you do this
table.beginUpdates()
table.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
table.endUpdates()
}

Answer 2

I think the key problem is in the Cell indexPath could not update when the table view delete the cell.
so we can try create a help array in the ViewController,help us update the really data to delate.
lazy var listHelper:Array<Int> = {
var array = [Int]()
for i in 0...self.data.count {
array.append(i)
}
return array
}()
update the removeCell function to this :
func removeCell(indexPath: NSIndexPath) {
// if first delete delete the date, and remove index in help list
if indexPath.row < listHelper.count - 1 && indexPath.row == listHelper[indexPath.row] {
data.removeAtIndex(indexPath.row)
tableView.beginUpdates()
tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
tableView.endUpdates()
listHelper.removeAtIndex(indexPath.row)
}else {
// if indexPath.row != listHelper[indexPath.row],we find the really data we want to delete, used Array extension .indexOf
let locationData = listHelper.indexOf(indexPath.row)
data.removeAtIndex(locationData!)
// we create NSIndexPath and delete it.
let theindexPath = NSIndexPath(forRow: locationData!, inSection: 0)
tableView.beginUpdates()
tableView.deleteRowsAtIndexPaths([theindexPath], withRowAnimation: UITableViewRowAnimation.Automatic)
tableView.endUpdates()
listHelper.removeAtIndex(locationData!)
}
}
the Extension of Array :
extension Array {
func indexOf <U: Equatable> (item: U) -> Int? {
if item is Element {
return Swift.find(unsafeBitCast(self, [U].self), item)
}
return nil
}
}
My English is poor. and U can see the code . I had try it, and it can work. I hope can solve you problem.