CODEWITHSUNDEEP
iosiphoneswiftuitableview
Rodrigo Ruiz
Rodrigo Ruiz

Reputation: 4355

Start UITableView scrolled to bottom

How do I start a UITableView scrolled to the last cell?

just have a plain UITableView(frame: CGRectZero, style: UITableViewStyle.Plain) that when presented on screen, will start scrolled all the way to the bottom.

I've tried:

// 1
reloadData()
scrollToRowAtIndexPath(
    NSIndexPath(forItem: dataArray.count-1, inSection: 0),
    atScrollPosition: .Top, animated: false
)

// 2
reloadData()
var contentOffset = self.contentOffset
contentOffset.y = CGFloat.max
setContentOffset(contentOffset, animated: false)

on the tableView's init method (in my subclass)

I've also tried the classic CGAffineTransformMakeScale(1,-1) hack, but that makes my cells stick to the bottom and I want them stuck the the top (but scrolled to the bottom). (that is only relevant if I have few cells, when they don't fill the entire UITableView space)

EDIT: another detail, I'm using dynamic cells UITableViewAutomaticDimension.

Upvotes: 9

Views: 4794

Answers (3)

CoolPineapple
CoolPineapple

Reputation: 385

You can either set the content offset:

tableview.contentOffset = CGPoint(x: ??, y: ??)

Or scroll to the desired row

tableview.contentOffset.scrollToItem(at: IndexPath(row: tableview.contentOffset.numberOfItems(inSection: 0) - 1, section: 0), at: .bottom, animated: false)

To get this to happen before the view appears so that the user doesn't see the transition, simply call these methods in the viewDidLayoutSubviews() lifecycle method of your view controller.

Upvotes: 0

Irfan Anwar
Irfan Anwar

Reputation: 1918

This will scroll to bottom without any glitch, but if you use Tableview scroll-to-row property then there will be glitch.

For Swift 3 use

self.TableView.reloadData() // To populate your tableview first
//Since we have to wait until the table is reload
 DispatchQueue.main.async {
 let bottomOffset = CGPoint(x: 0, y: self.TableView.contentSize.height - self.TableView.frame.size.height)
 self.TableView.setContentOffset(bottomOffset, animated: false)
 }

For Objective C use

[YourTableView reloadData]; // To populate your tableview first

[YourTableView setContentOffset:CGPointMake(0, YourTableView.contentSize.height - YourTableView.frame.size.height)];

Upvotes: 8

aatalyk
aatalyk

Reputation: 391

EDIT:

animated: false

func scrollBottom() {
    let lastIndex = NSIndexPath(forRow: dataArray.count-1, inSection: 0)
    self.tableView.scrollToRowAtIndexPath(lastIndex, atScrollPosition: UITableViewScrollPosition.Bottom, animated: false)
}

TEST CODE:

import UIKit

class TableViewController: UITableViewController {

var goButton = UIButton()

override func viewDidLoad() {
    super.viewDidLoad()

    tableView.delegate = self
    tableView.dataSource = self

    goButton = UIButton(frame: CGRect(x: 0, y: 0, width: 100, height: 50))
    goButton.backgroundColor = UIColor.blueColor()
    goButton.addTarget(self, action: #selector(TableViewController.scrollBottom), forControlEvents: .TouchUpInside)
    self.view.addSubview(goButton)
}



override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    // #warning Incomplete implementation, return the number of rows
    return 500
}


override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell

    cell.textLabel?.text = "Hello, World!"

    return cell
}

func scrollBottom() {
    let lastIndex = NSIndexPath(forRow: 499, inSection: 0)
    self.tableView.scrollToRowAtIndexPath(lastIndex, atScrollPosition: UITableViewScrollPosition.Bottom, animated: false)
}

}

Upvotes: 1

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