Stange animation when deleting UITableViewCell

问题:

I'm using this code to delete a UITableViewCell, but when I swipe to delete, it is showing the minus sign on the right first, then deleting.

I took a video to help illustrate my point: Video on YouTube

- (void)setEditing:(BOOL)editing animated:(BOOL)animate
{
    [self.tableView setEditing: !self.tableView.editing animated:YES];

    if (self.tableView.editing)
        [self.navigationItem.leftBarButtonItem setTitle:@"Done"];
    else
        [self.navigationItem.leftBarButtonItem setTitle:@"Edit"];
}

-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) 
    {
        PFObject *routine= [self.routineArray objectAtIndex:indexPath.row];
        [routine deleteInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
            if (!error) {
                [self.routineArray removeObjectAtIndex:indexPath.row];
                [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
                //         [MKInfoPanel showPanelInView:self.view type:MKInfoPanelTypeError title:@"Routine Deleted" subtitle:@"You have succesfully deleted the routine!" hideAfter:2];
            } else {
                NSLog(@"%@", error);
            }
        }];   
    }
}

Edit:

- (void)loadData
{
    PFQuery *query = [PFQuery queryWithClassName:@"Routine"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (!error) {
            self.routineArray = [objects mutableCopy];
            [self.tableView reloadData];
        } else {
            NSLog(@"Error: %@ %@", error, [error userInfo]);
        }
    }];   
}

-(void)addRoutine
{   
    PFObject *routine = [[PFObject alloc] initWithClassName:@"Routine"];
    [routine setObject:self.entered forKey:@"name"]; 
    [routine saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
        if (!error) {
            [self loadData];
        } else {
            // There was an error saving the routine.
        }
    }];   
}

回答1:

It looks like there are two issues. The first it looks like -deleteInBackgroundWithBlock: is taking a noticeable amount of time to execute it's block after the delete button is pressed. You can try deleting the dataSource object and tableView row before deleting the data from the core data store if you aren't using a NSFetchedResultsController

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (editingStyle == UITableViewCellEditingStyleDelete) 
    {
        PFObject *routine = [self.routineArray objectAtIndex:indexPath.row];
        [self.routineArray removeObjectAtIndex:indexPath.row];
        [self.tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade];
        [routine deleteInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
            if (!error) {
                //[MKInfoPanel showPanelInView:self.view type:MKInfoPanelTypeError title:@"Routine Deleted" subtitle:@"You have succesfully deleted the routine!" hideAfter:2];
            } else {
                NSLog(@"%@", error);
            }
        }];   
    }
}

You can also use a different animation if you prefer something other than fading out the opacity of the row. If you are targeting iOS 5.0 only, you can use UITableViewRowAnimationAutomatic to have UIKit attempt to choose the best looking animation given the circumstances.

The other issue looks like editing mode is turned back on after delete is pressed. You shouldn't need to override -setEditing:animated: so try removing that method completely. In your -viewDidLoad: you can do the following to get editing behavior for free:

self.navigationItem.leftBarButtonItem = self.editButtonItem;

See:

• An Example of Deleting a Table-View Row
• UIViewController Class Reference: -editButtonItem

It should also be noted that when you are checking the editing status, you should use the isEditing accessor.

To avoid calling -reloadData, you just add the single new object to your dataSource array, then add a tableView row, then save it to the core data store. This is simply the opposite of what you had to do when deleting a row from the table view. This will work if you need to append the routine object to the end of the tableView and there is no custom sort order. Otherwise, you must insert the routine object into self.routineArray at the desired index and then create the proper indexPath to insert the tableView row at the desired location within the tableView.

- (void)addRoutine
{   
    PFObject *routine = [[PFObject alloc] initWithClassName:@"Routine"];
    [routine setObject:self.entered forKey:@"name"]; 
    [self.routineArray addObject:routine];
     NSIndexPath *indexPath = [NSIndexPath indexPathForRow:([self.routineArray count]-1) inSection:0];
    [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath withRowAnimation:UITableViewRowAnimationAutomatic
    [routine saveInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
        if (!error) {
            [self loadData];
        } else {
            // There was an error saving the routine.
        }
    }];   
}