顯示具有 UITableView 標籤的文章。 顯示所有文章
顯示具有 UITableView 標籤的文章。 顯示所有文章

2016年4月13日 星期三

Update UITableViewCell from itself

The code that can update the cell itself.
// update UI on main thread
dispatch_async(dispatch_get_main_queue(), ^{
    //set cell need update
    [self setNeedsUpdateConstraints];
    [self updateConstraintsIfNeeded];
    [self setNeedsLayout];
    [self layoutIfNeeded];
    //trying to get the tableview
    id view = [self superview];
    // different level of UITableView wrapping in different iOS version,
    // for more detail please see:
    //  stackoverflow 
    while (view && [view isKindOfClass:[UITableView class]] == NO) {
        view = [view superview];
    }
    
    if (view) {
        UITableView *tableView = (UITableView *)view;
        NSIndexPath *indexPath = [tableView indexPathForCell:self];
        if (indexPath) {
            [tableView reloadRowsAtIndexPaths:@[indexPath] 
                             withRowAnimation:UITableViewRowAnimationNone];
        }
    }
});

2016年4月4日 星期一

[iOS] UITableView scroll to top when typing in the textfield will scroll to a wrong location

My case is this:

I have a static table, with hidden cell(height = 0), custom cell that will open keyboard, and a reset button(that will reload table and scroll to top)

What is the problem:

Scroll to top will go to invalid offset.

How to regenerate:

type in the keyboard, reset(which scroll to top and reload the keyboard) and there will be space between my top cell and top of table (just like hidden cell consumed some space)

---

At first I thought it is the hidden cell problem, but it turns out to be problem on [tableView reloadData]

**[tableView reloadData] will interrupt scrolling, so make sure you call [tableView setContentOffset:] or [tableView scrollToRowAtIndexPath:] after all reload is done.

Reference: stackoverflow