Swift TableViewCells 没有出现

Question

I got a ViewController , with two UITableView in it. They both get data from the same object, but from different arrays inside that object.

My second Tableview doesn't show me all the items, only 5.

The TableViews are both dynamic and size themself.

Here is my cellForRowAt function:

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        if tableView == tableViewSteps,  //This is the table that doesn't show right
            let cell = tableView.dequeueReusableCell(withIdentifier: "stepsCell", for: indexPath) as? StepsTableViewCell {

            let text = detailItem?.itemStepAr[indexPath.row] as! String

            cell.textAreaOutlet.text = "Schritt \(indexPath.row + 1) \n\(text)"

            let textAsNSString = cell.textAreaOutlet.text as NSString
            let lineBreakRange = textAsNSString.range(of: "\n")
            let newAttributedText = NSMutableAttributedString(attributedString: cell.textAreaOutlet.attributedText)
            let boldRange: NSRange
            if lineBreakRange.location < textAsNSString.length {
                boldRange = NSRange(location: 0, length: lineBreakRange.location)
            } else {
                boldRange = NSRange(location: 0, length: textAsNSString.length)
            }

            newAttributedText.addAttribute(NSAttributedString.Key.font, value: UIFont.preferredFont(forTextStyle: UIFont.TextStyle.headline), range: boldRange)

            cell.textAreaOutlet.attributedText = newAttributedText

            let fixedWidth = cell.textAreaOutlet.frame.size.width
            let newSize = cell.textAreaOutlet.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat.greatestFiniteMagnitude))
            cell.textAreaOutlet.frame.size = CGSize(width: max(newSize.width, fixedWidth), height: newSize.height)
            cell.textAreaOutlet.isScrollEnabled = false
            tableStepsHeight = tableStepsHeight + Int(newSize.height)

            cell.textAreaOutlet.textColor = UIColor.lightGray

            tableViewSteps.frame = CGRect(x:0, y: currentViewHeight + 20, width: 375, height: tableStepsHeight)
            changeScrollHeight()
            return cell

        }

        else {
        let cell = tableView.dequeueReusableCell(withIdentifier: "ingredsCell")! //1.
        let text = detailItem?.itemIngredAr[indexPath.row]

        cell.textLabel?.text = text as? String

        cell.textLabel?.font = UIFont(name: "Futura-Medium", size: 17)

        cell.textLabel?.textColor = UIColor.lightGray

        return cell
        }
    }

as commented, the first tableview is the one, that doesn't work properly. It only runs 5 times, when I watch it with the debugger, but there are more Items in the Array.

Edit:

Here is my numberOfRowsInSection function

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        if (tableView == tableViewSteps) {
            return detailItem?.itemStepAr.count ?? 0
        }
        else {
        return detailItem?.itemIngredAr.count ?? 0
        }
    }

Edit 2:

When I enable scrolling in my TableView and then try to scroll, all the items appear. But the scrolling should be disabled, because it automatic resizes (which works)

Final edit:

I added like some more height to the tableView and enabled scroll (but disabled the bounce, so u don't see anything from the scroll)

Now it loads properly and everything works fine

Answer 1

A UITableView works with recycling UITableViewCell s. This means that a tableview will only load the visible cells first, and only when you scroll, will it load more cells (by recycling the old cells).

The issue I can see is that you may try to get the height of the tableview, to update a height constraint (so the tableview shows in its entirety). But that may be an incorrect calculation (as said before, it only instantiates the first x cells, so it can't know the height of the remaining cells). Also, this calculation should never be performed from cellForRowAt , as that method should never do things outside the cell (unless you want to know when a cell has become visible).

You can fix this by making your cells all have a predefined height, and then multiplying that by the number of cells.

If you have self-sizing cells, it can't be done (read: it can be done, but it's too unwieldy and inefficient to be practical).

You could try to look into taking all other views that should scroll above and below the tableview, into tableviewcells. Then you can just use a regular tableview, no fancy height constraints and calculations needed.