UITableView contentOffSet is not working properly

Question

In viewWillAppear, I have added UISearchBar as my headerview of UITableView. When view loads, I hides UISearchbar under <

Answer 1

Not sure what the reason is (don't have time to research it right now), but I solved this issue by using performSelector after a delay of 0. Example:

- (void)viewWillAppear:(BOOL)animated {
    ...
    [self performSelector:@selector(hideSearchBar) withObject:nil afterDelay:0.0f];
}

- (void)hideSearchBar {
    self.tableView.contentOffset = CGPointMake(0, 44);
}

Answer 2

The problem may be with the search bar size. Try the following line of code.

[searchBar sizeToFit];

Answer 3

The line of code is working as it should.

Explaination of contentOffset of a UITableView:

For example, if you have a table view of height 100. Its content may be more than it's view, say 150. contentOffset will tell the table from where in the content to start from. Say contentOffset = (0, 40), the content will be shown after 40 of it's height.

Note: Once the content is scrolled, there is no affect of the previously set contentOffset.

Answer 4

In earlier versions of the iOS SDK, methods such as viewWillAppear ran on the main thread, they now run on a background thread which is why the issue now occurs.

Most callbacks tend to fire on a background thread so always check for thread safety when doing UI calls.

Dispatch the change to the content offset on the main thread:

Objective C

dispatch_async(dispatch_get_main_queue(), ^{
    CGPoint offset = CGPointMake(0, self.searchBar.bounds.height)
    [self.tableView setContentOffset:offset animated:NO];
});

Swift 3

DispatchQueue.main.async {
            let offset = CGPoint.init(x: 0, y: self.searchBar.bounds.height)
            self.tableView.setContentOffset(offset, animated: false)
        }

Answer 5

This worked for me.

self.tableView.beginUpdates()
self.tableView.setContentOffset( CGPoint(x: 0.0, y: 0.0), animated: false)
self.tableView.endUpdates()

Objective-C :

[_tableView beginUpdates];
[_tableView setContentOffset:CGPointMake(0, 0)];
[_tableView endUpdates];

Answer 6

This worked for me:

// contentOffset will not change before the main runloop ends without queueing it, for iPad that is
dispatch_async(dispatch_get_main_queue(), ^{
    // The search bar is hidden when the view becomes visible the first time
    self.tableView.contentOffset = CGPointMake(0, CGRectGetHeight(self.searchBar.bounds));
});

Put it in your -viewDidLoad or -viewWillAppear