IOS：强制 tableView 单元格在点击时动画更改

Question

I am trying to perform an animation on a cell when the accessory view is tapped. The tapped delegate method is firing and I can get the row to do something--change label, but it is ignoring the animation (or in another case--not even making the change.) How can I get the animation to work properly?

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath{

    MyCustomCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];

                    [UIView animateWithDuration:5.0
                                    delay: 5.0
                                    options: UIViewAnimationOptionCurveEaseIn
                                                                 animations:^{
//NEXT TWO LINES HAVE NO EFFECT ON CELL SO COMMENTED OUT
//cell.nameLabel.text = @"Thank you. FIRST ANIMATE TRY";                              
// [self.tableView reloadRowsAtIndexPaths:@[indexPath] withRowAnimation:UITableViewRowAnimationFade];
//NEXT THREE LINES CHANGE TEXT BUT WITHOUT ANIMATION
[self.tableView beginUpdates];
cell.nameLabel.text = @"Thank you. Second try!";
[self.tableView endUpdates];                                                                                
                             }
                             completion:^(BOOL finished){
                                 NSLog(@"animation finished");
                             }];     
    }

BTW I also tried explicitly dispatching this in the main queue but it had no effect. It should already be in main queue.

Answer 1

First of all, you don't need to call beginUpdates or endUpdates . Second, you can't animate the change of a label's text value.

What you need to is have a label on the cell and initialize the alpha property to 0.0. When accessoryButtonTappedForRowWithIndexPath is called set the alpha property to 1.0 inside of your animation block.

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    AwesomeCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell" forIndexPath:indexPath];
    cell.thankYouLabel.text = @"Thank you";
    cell.thankYouLabel.alpha = 0.0;
    return cell;
}

- (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
{
    AwesomeCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    [UIView animateWithDuration:1.0 animations:^{
        cell.thankYouLabel.alpha = 1.0;
    }];
}