[iOS]UITableView using auto layout, how to scroll to bottom [duplicate] - ios

Question

I have a UITableView with cells that are dynamically updated. Everything works fine apart from when tableview.reload is called (see below) to refresh the cells in the table I would like the table to scroll to the bottom to show the new entries.
- (void)reloadTable:(NSNotification *)notification {
NSLog(#"RELOAD TABLE ...");
[customTableView reloadData];
// Scroll to bottom of UITable here ....
}
I was planning to use scrollToRowAtIndexPath:atScrollPosition:animated: but then noticed that I don't have access to an indexPath.
Does anyone know how to do this, or of a delegate callback that I could use?

Answer 1

Use:
NSIndexPath* ipath = [NSIndexPath indexPathForRow: cells_count-1 inSection: sections_count-1];
[tableView scrollToRowAtIndexPath: ipath atScrollPosition: UITableViewScrollPositionTop animated: YES];
Or you can specify the section index manually (If one section => index=0).

Answer 2

Another solution is to flip the table vertically, and flip each cell vertically:
Apply the transform to the UITableView when initializing:
tableview.transform = CGAffineTransformMakeScale(1, -1);
and in cellForRowAtIndexPath:
cell.transform = CGAffineTransformMakeScale(1, -1);
This way you don't need workarounds for scrolling issues, but you will need to think a little harder about contentInsets/contentOffsets and header/footer interactions.

Answer 3

-(void)scrollToBottom{
[self.tableView scrollRectToVisible:CGRectMake(0, self.tableView.contentSize.height - self.tableView.bounds.size.height, self.tableView.bounds.size.width, self.tableView.bounds.size.height) animated:YES];
}

Answer 4

//In swift
var iPath = NSIndexPath(forRow: self.tableView.numberOfRowsInSection(0)-1,
inSection: self.tableView.numberOfSections()-1)
self.tableView.scrollToRowAtIndexPath(iPath,
atScrollPosition: UITableViewScrollPosition.Bottom,
animated: true)

Answer 5

Swift 3
For all the folks here trying to figure out how to solve this problem the key is to call the .layoutIfNeeded() method after .reloadData() :
tableView.reloadData()
tableView.layoutIfNeeded()
tableView.setContentOffset(CGPoint(x: 0, y: tableView.contentSize.height - tableView.frame.height), animated: false)
I was working with multiple sections in UITableView and it worked well.

Answer 6

Fot Swift 5
extension UITableView {
func scrollToBottom(animated: Bool = true) {
let section = self.numberOfSections
if section > 0 {
let row = self.numberOfRows(inSection: section - 1)
if row > 0 {
self.scrollToRow(at: IndexPath(row: row-1, section: section-1), at: .bottom, animated: animated)
}
}
}
}

Answer 7

As this is something you might want to use really often, I suggest that you create a class extension on UITableView :
extension UITableView {
func scrollToBottom(animated: Bool = true) {
let section = self.numberOfSections
if section > 0 {
let row = self.numberOfRowsInSection(section - 1)
if row > 0 {
self.scrollToRowAtIndexPath(NSIndexPath(forRow: row - 1, inSection: section - 1), atScrollPosition: .Bottom, animated: animated)
}
}
}
}

Answer 8

This is another solution, worked well in my case, when cell height is big.
- (void)scrollToBottom
{
CGPoint bottomOffset = CGPointMake(0, _bubbleTable.contentSize.height - _bubbleTable.bounds.size.height);
if ( bottomOffset.y > 0 ) {
[_bubbleTable setContentOffset:bottomOffset animated:YES];
}
}

Answer 9

extension is better to be done on UIScrollView instead of UITableView, this way it works on scrollView, tableView, collectionView (vertical), UIWebView (inner scroll view), etc
public extension UIScrollView {
public func scrollToBottom(animated animated: Bool) {
let rect = CGRectMake(0, contentSize.height - bounds.size.height, bounds.size.width, bounds.size.height)
scrollRectToVisible(rect, animated: animated)
}
}

Answer 10

Swift 5
func scrollToBottom() {
let section = self.tableView.numberOfSections
let row = self.tableView.numberOfRows(inSection: self.tableView.numberOfSections - 1) - 1;
guard (section > 0) && (row > 0) else{ // check bounds
return
}
let indexPath = IndexPath(row: row-1, section: section-1)
self.tableView.scrollToRow(at: indexPath, at: .top, animated: true)
}
I dont agree that we should user cells_count,sections_count,self.dateSource.countand so on, Instead, the delegate will be better.

Answer 11

This is the best way.
- (void)scrollToBottom
{
CGFloat yOffset = 0;
if (self.tableView.contentSize.height > self.tableView.bounds.size.height) {
yOffset = self.tableView.contentSize.height - self.tableView.bounds.size.height;
}
[self.tableView setContentOffset:CGPointMake(0, yOffset) animated:NO];
}

Answer 12

try this code, It may help you:
self.tableView.reloadData()
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+0.1, execute: {
let indexPath = IndexPath(row: self.dateSource.count-1, section: 0)
self.tableView.scrollToRow(at: indexPath, at: UITableViewScrollPosition.bottom, animated: true)
})