Get height of each rows of UITableView - ios

Question

Is there any way by which I can get row height of each row in a UITableView. I have a UITableView which contains data which is dynamic, and I am using
self.tableView.rowHeight = UITableViewAutomaticDimension
to make dynamic row heights.
But I want to change height of overall UITableView as well, for that I need height of all the rows after reload of data.
I tried using
self.tableView.layoutIfNeeded()
self.tableViewHeightContraint.constant = self.tableView.contentSize.height
But due to unknown reason it is giving me height less than what exactly it has, after I add 3 or 4 records in UITableView so thinking of other way around. To calculate height of each rows and then summing them up.
I am doing in Xcode 7.2, iOS 9 and Swift 2

Answer 1

var dictionaryOfCellHeight = [Int : CGFloat]()
var dataArray = [String]()
func tableView(tableView: UITableView!, heightForRowAtIndexPath indexPath: NSIndexPath!) -> CGFloat {
if dictionaryOfCellHeight[indexPath.row] == nil
{
var frame : CGRect = tableView.rectForRowAtIndexPath(indexPath)
if indexPath.row == dataArray.count
{
dictionaryOfCellHeight[indexPath.row] = frame.size.height
//calculate total height and reload table
}
else
{
dictionaryOfCellHeight[indexPath.row] = frame.size.height
}
}
}

Answer 2

in Swift 3.0
let myRowHeight = yourTableView.rowHeight

Answer 3

To change the height of Tableview , you don't need to calculate the height of all UITableViewCells and set to TableView.
Set the height of each UITableViewCell properly in heightForRowAtIndexPath method. This will automatically set the scrollable height to your Tableview

Answer 4

You can use this
CGRect frame = [tableView rectForRowAtIndexPath:indexPath];
NSLog(#"row height : %f", frame.size.height);
Using frame.size.height you can get height of particular row

Answer 5

This is because self.tableView.contentSize.height returns number of rows * estimatedRowHeight, which is not equivalent to actual height of the table view. What you need is to get the individual cell heights through visibleCells, then sum those up to get the table view's height.
Refer to this for the answer:
https://stackoverflow.com/a/40081129/4076956

Answer 6

Maybe the table is not resizing its content, so if you try using [self. tableView layoutSubviews]; to force the resizing, it may work. [self. tableView layoutIfNeeded]; not necessarily forces the update.

Answer 7

Functionally (one-liner) 👌
NOTE: my section array stores the rows in the .data var
let heightOfAllRows:CGFloat = sections.enumerated().map { arg -> [(section:Int,row:Int)] in
return arg.element.data.indices.map{ i in
(section:arg.offset,row:i)
}
}.flatMap{$0}.reduce(0){
return $0 + self.tableView(self, heightForRowAt: .init(row: $1.row, section: $1.section))
}