I put my UITableView in UIScrollView > View > StackView.
And I implemented table view in View Controller as usual with numberOfRowsInSection and cellForRowAt. Here's my extension.
extension OrderViewController: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("DEBUG: orderItems.count - \(orderItems.count)")
return orderItems.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: OrderCell.id, for: indexPath) as! OrderCell
cell.configure(orderItems[indexPath.row])
return cell
}
}
But my simulator actually shows empty cells. I already checked the orderItems array only has 2 members.
I guess it is because either auto layout or stack view. In the stack view, I gave height constraints for every views except table view since it has to have dynamic cell number.
I don't know what I have to change.
table view's attribute
This is because your tableview has full height with related your view. Just add on viewDidLoad
yourTableView.tableFooterView = UIView()
But if you want dynamic height for your tableview then do that;
Give a height constraint for your tableview
Create an IBOutlet for this constraint
After you reload your tableview
heightConstraint.constant = yourRowHeight * arrayCount
self.view.layoutIfNeeded()
Related
I am currently learning IOS. I have UITableView embedded in NavigationController and UITabBar. I have populated the TableView with data and its showing in the table when I run the app. The TableView is not scrolling and for the life of me I can't figure out why.
Here is the table view code
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
return petitions.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
// code to initialize the cell here
return cell
}
Any suggestions as to what am missing, or how to make it work is welcomed
Maybe if you changed your table view scroll options. So table view is a scroll view. Options must be like below:
So I have 2 Views that are shown inside a UIView, based on what is selected on the SegmentViewController. I create dummy data, returning 20 row of a custom cell. This works great.
Everything is fine, till I interact with the TableView.
Bellow is my code:
GoalsViewController.swift
import UIKit
class GoalsViewController: UIViewController {
#IBOutlet weak var goalsTableView: UITableView!
let goalCellIdentifier = "goalCell"
override func viewDidLoad() {
super.viewDidLoad()
goalsTableView.delegate = self
goalsTableView.dataSource = self
goalsTableView.register(UINib(nibName: "GoalsViewCell", bundle: nil), forCellReuseIdentifier: goalCellIdentifier)
goalsTableView.reloadData()
}
}
extension GoalsViewController: UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 20
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = goalsTableView.dequeueReusableCell(withIdentifier: goalCellIdentifier, for: indexPath) as! GoalsViewCell
cell.goalTitle.text = "aaaaa"
return cell
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
print("Selected \(indexPath.row)")
}
}
After any of the empty rows is selected, the didSelectRowAt is not called, so the cells are not there at all. I tried to find a solution, but I was only to find issues about empty lists, before being populated.
What could be the reason for the empty tableview?
I might be wrong here but one thing that I've noticed is that you are not implementing a function which sets the height of each cell.
// Specify the height of your cells
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100 // Or your given cell height.
}
So here is my theory: If you are using constraints something is missing and your cell's height can't be identified by constraints alone or you are not using constraints at all thus you must use heightForRowAt function to specify each cell's height.
I will explain what was the issue for people who probably did not know (like me).
So my UITableView is inside a UIView that changes based on what the user is selecting. In total I had 2 different Views that where switching. The reason that it was emptying it was because my parent ViewController, could not access the delegate for UITableView. To fix that, after adding a subview to the UIView, you need also to move the ViewController to the parent controller. In code it goes like this.
// Empty array of UIViewControllers
var views: [UIViewController]!
// Add the UIViewControllers to the array
views = [UIViewController()]
views.append(EventsViewController())
views.append(GoalsViewController())
for view in views {
// Needed to adjust the size of Subview to size of View
view.view.frame = containerView.bounds
// Add the subviews
containerView.addSubview(view.view)
}
// Bring the view in position 1 to the front of the UIView
containerView.bringSubviewToFront(views[1].view)
// Add Views[1] UIViewController as a child to the parent controller
self.addChild(views[1])
views[1].didMove(toParent: self)
// After done with everything with the UIViewController remove it
views[1].removeFromParent()
addChild Apple.com
didMove Apple.com
I have a UITableViewCell in xib and its outlets in corresponding UITableViewCell subclass. I am returning height of cell from
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) ->CGFloat {
return 400
}
I need to hide some views based on the data available in each row of the table and bottom view should shifted to top of the cell. When I am hiding view from cell then there is empty space left in place of hidden view & bottom views are not shifting to top part of the cell.
Here is How I am hiding cell view.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
.....
cell.opetion4.isHidden = true
cell.opetion3.isHidden = true
}
This is my cell.
After hide 2 middle labels it is looking as follows.
But I want to remove this empty space and want to shift bottom label to top as follows.
At first, make the height of UITableViewCell to UITableView.automaticDimension
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension
}
Embed all of your questionLabels in a UIStackView (vertical) excluding bottomLabel. Set AutoLayoutConstraint between UIStackView and bottomLabel.
Set the numberOfLines property of UILabels to 0(zero).
Set the Distribution of the UIStackView as Fill
Then, in your tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell method hide the labels. And it will automatically handle the spaces between UILabels
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "MyCell", for: indexPath) as! MyCell
cell.questionLabel1.text = labelOneText[indexPath.row]
cell.questionLabel2.text = labelTwoText[indexPath.row]
cell.questionLabel3.text = labelThreeText[indexPath.row]
if labelOneText[indexPath.row] == "" {
cell.questionLabel1.isHidden = true
}
if labelTwoText[indexPath.row] == "" {
cell.questionLabel2.isHidden = true
}
if labelThreeText[indexPath.row] == "" {
cell.questionLabel3.isHidden = true
}
return cell
}
Final Output:
First I suggest you to set UITableViewCell Height to automatic dimensions . Attach all the children to one another and last child to uiview of xib . Now hiding view does not adjust size of cell so you need to play with height constraint of uiview you are hiding .
Make height constraint as strong in IBOutlet else it will crash since cells are re-using and constraint after setting once will become nil . You need to make sure that height constraint are change according to display cell requirement , thats mean for each cell maintain some datasource that decide to show or hide the view every time when cellforrowatIndexpath method called.
Hope this helps
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) ->CGFloat {
return UITableView.automaticDimension
}
now in cell, put all your views and there siblings which you want to hide/show in UIstackview (horizontal). now if you hide one view, it will be hidden and its apace will be also hidden to no white space will be showing, and no need to handle extra constraints. it will all handled by stackview.
I have created UIViewController and added UITableView on it (pinned to all four edges with autolayout).
Then I set estimatedRowHeight (44) and rowHeight (UITableViewAutomaticDimension) and returned 5 custom cells. And it worked.
Now, I want to add custom UITableViewHeaderFooterView that would have dynamic height.
I'm doing next:
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 88.0
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
return R.nib.orderStatusHeaderView.firstView(owner: self)!
}
My OrderStatusHeaderView is a xib view that has UITableView on it pinned to all 4 edges with autolayout.
OrderStatusHeaderView:
final class OrderStatusHeaderView: UITableViewHeaderFooterView {
#IBOutlet weak var tableView: UITableView! {
didSet {
tableView.dataSource = self
tableView.delegate = self
tableView.rowHeight = 44.0
}
}
}
extension OrderStatusHeaderView: UITableViewDataSource, UITableViewDelegate {
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 2
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = UITableViewCell(style: .default, reuseIdentifier: "\(indexPath.row)")
cell.textLabel?.text = "\(indexPath.row)"
cell.backgroundColor = .red
return cell
}
}
This displays like:
And when I tap or scroll, all red cells disappears. What could it be? And how to make UITableView dynamically load content and UITableViewHeaderFooterView will size itself so it fit UITableView.contentSize. Is it possible?
Check out:
tableView(_:estimatedHeightForFooterInSection:)
and
tableView(_:heightForFooterInSection:)
You also have the equilavant for headerInSection.
Since you are asking for a table's header and footer view, you can skip the delegate methods you describe. Those (as the name implies) are for SECTION headers and footers.
When you set a view that is using AutoLayout as the table's header or footer, the its frame still has a zero height (That's why buttons in such view for example won't work as they are not receiving the touches).
To correctly size a table's header or footer views using AutoLayout you have to apply a trick to actually calculate the height yourself, and set the headerView again. It is described in detail in many posts like these:
https://stackoverflow.com/a/28102157/756039
https://gist.github.com/marcoarment/1105553afba6b4900c10
http://collindonnell.com/2015/09/29/dynamically-sized-table-view-header-or-footer-using-auto-layout/
http://roadfiresoftware.com/2015/05/how-to-size-a-table-header-view-using-auto-layout-in-interface-builder/
Hope this helps.
Requirement :
I have a list of UITableviewCell loaded from a nib that I'm presenting on UITableview. The first time I open the UIViewController all cells are shown correctly and work as expected.
Issue :
If I navigate back to the parent and then open the UIViewController again the UITableviewCell are 'invisible'. I say invisible because with a breakpoint in cellForRowAt I can see that the table view does load all cells and the cells are valid.
Code :
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 13
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 40
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = (project?.sliderData.sliders[indexPath.row].view)! as UITableViewCell
print(cell.contentView.subviews.count)
if let left = cell.viewWithTag(2) as? UILabel {
left.text = "left"
}
if let middle = cell.viewWithTag(3) as? UILabel {
middle.text = "middle"
}
if let right = cell.viewWithTag(4) as? UILabel {
right.text = "right"
}
return cell
}
Screen Shot Image
Expected observation :
I was thinking that maybe the subviews of the cells get released because I don't have any bindings to them in IB. To test this I'm printing the count of subviews and writing some text to the subview labels. And everything seems to go fine, the cells are loaded and the labels are there but the cells just don't show up.
But then, if I scroll the TableView up and down a little to get some cells updated those cells do appear at the top and bottom of the view as shown in the pic.
You need to call dequeueReusableCell(withIdentifier: "cell") inside your code then will show your table cell. It will reuse cell for your all numbers of row data content.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! UITableViewCell
return cell
}
More Details : How to create uitableview with multiple sections in iOS Swift.
Did not find reason why the tableView behaves the way it does so I solved the issue by dequeueing default cells. The views provided by the slider objects are added as subviews to the dequeued cells. Now the subviews can of course be any UIViews.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCell(withIdentifier: "sliderCell")
if cell == nil {
cell = UITableViewCell.init(style: .default, reuseIdentifier: "sliderCell")
}
cell?.addSubview((project?.sliderData.sliders[indexPath.row].view)!)
return cell!
}