在Swift中从UITableView删除单元格

Question

When deleting a cell from the tableView, the animation runs fine, but the tableView data isn't reloaded. I tried running without .beginUpdates() and .endUpdates() and instead used .reloadData() , and the process worked but the animation didn't work.

    func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    switch editingStyle {
    case .Delete:
        // remove the deleted item from the model
        let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
        let context:NSManagedObjectContext = appDel.managedObjectContext
        context.deleteObject(coreData[indexPath.row] as NSManagedObject)
        coreData.removeAtIndex(indexPath.row)
        do {
            try context.save()
        } catch {
            print("Error deleting NSManagedObject")
        }


        tableView.beginUpdates()
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
        tasks.removeAtIndex(indexPath.row)
        names.removeAtIndex(indexPath.row)
        ids.removeAtIndex(indexPath.row)
        tableView.endUpdates()
        // remove the deleted item from the `UITableView`

    default:
        return

    }

}

By the way, the tasks array is the the main data for the tableView.

How can I reload the data as I delete a cell, WITH the smooth deletion animation?

Answer 1

Two things to consider:

1. You must update the data model before you update the table view. Therefore the order of the code must be:

    tasks.removeAtIndex(indexPath.row) names.removeAtIndex(indexPath.row) ids.removeAtIndex(indexPath.row) tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade) 

2. There is no need for the calls to begin/endUpdates since you only make a single call to update the table view.

Answer 2

将所有removeAtIndex...行移动到beginUpdates之前，必须先从数据中删除对象，然后才能删除行