CODEWITHSUNDEEP
iosswiftuitableview
lychee
lychee

Reputation: 1851

UITableView setting row Height not having effect

Why is it that when I set tableView.rowHeight = 100 in viewDidLoad() I always get the default height value of 44.0? I tried setting tableView.estimatedHeight =100 as well but no luck, I tried setting the delegate method tableView.heightForRowAt as well but that doesn't seem to have any effect as well what so ever. So the question is: how do you set the height for a tableView Cell?

    override func viewDidLoad(){ // tableView viewDidLoad
    super.viewDidLoad()
    tableView.rowHeight = 100
    tableView.register(TickerCell.self, forCellReuseIdentifier: "Cell")
}
    // Custom Cell Init 
    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)
    backgroundColor = .clear
    print(frame.height) // always prints 44.0
    let symbolstack = UIStackView(arrangedSubviews: [symbolLabel,companyLabel])
    let sectorstack = UIStackView(arrangedSubviews: [sectorLabel,exchangeLabel])
    let mainStack = UIStackView(arrangedSubviews: [symbolstack,sectorstack])
    sectorstack.axis = .vertical
    symbolstack.axis = .vertical
    sectorstack.alignment = .trailing
    symbolstack.alignment = .leading
    symbolstack.distribution = .fillEqually
    sectorstack.distribution = .fillEqually
    mainStack.distribution = .fillProportionally
    addSubview(mainStack)
    mainStack.translatesAutoresizingMaskIntoConstraints = false
    mainStack.heightAnchor.constraint(equalTo: self.heightAnchor).isActive = true
    mainStack.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -45).isActive = true
    mainStack.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 15).isActive = true
    addSubview(WatchlistStar)
    WatchlistStar.translatesAutoresizingMaskIntoConstraints = false
    WatchlistStar.widthAnchor.constraint(equalToConstant: 15).isActive = true
    WatchlistStar.leadingAnchor.constraint(equalTo: mainStack.trailingAnchor, constant: 20).isActive = true
    WatchlistStar.heightAnchor.constraint(equalToConstant: 15).isActive = true
    WatchlistStar.centerYAnchor.constraint(equalTo: self.centerYAnchor).isActive = true
}

So the problem appears to be in the fact then in the cell init method the rowHeight I set In viewDidLoad does not seem to register, only in prepareForReuse when I print frame.height do I get 100 printed,So in which method do I setup the cell layout then?

Upvotes: 0

Views: 84

Answers (2)

matt
matt

Reputation: 535140

A cell is not born knowing its height, so init is a pointless place to look at the frame. In fact, it has no inherent height. Cells are reused. They take on a height only in relation to a particular row of the table where they are being used right at the moment. That height can change when the cell is used in a different row (because rows can be different heights). So your layout needs to cope with that.

In the code you have shown, you are using autolayout. The whole point of autolayout is that you don't care about the frame of things at any one moment. Everything adjusts automatically as the surrounding frame changes. Autolayout is about relationships.

So the solution in that case is: don't look at frame.height. You don't need to know it. Just lay out the relationships between the views and the cell, and everything will be correct when the cell appears, if you have used autolayout correctly.

On the other hand, as you now say in a comment "Im forced to [use autolayout] not because I want to" — okay, so if the goal is to do layout manually, like we did before there was autolayout, then the place to do it is in the data source's cellForRowAt:. Or you could try doing it in the cell's layoutSubviews if you want the cell to lay itself out. See the old edition of my book, online, for how we used to do this: http://www.apeth.com/iOSBook/ch21.html#_custom_cells

Be very careful to distinguish between adding subviews and resizing them. You don't want to make the mistake of adding subviews that you have already added. So add the subviews in init, sure, as it is called only once, but size them in a place where the actual size of the row has been communicated to the cell.

One more piece of advice. Your current code uses the phrase addSubview, meaning self.addSubview. That is totally wrong and illegal. Never never add a subview directly to a cell. Add it only to the cell's contentView, and size it in relation to that.

Upvotes: 1

Jijo Oommen
Jijo Oommen

Reputation: 1

override func viewDidLoad() {
    super.viewDidLoad()
    self.tableView.rowHeight = UITableView.automaticDimension;
    self.tableView.estimatedRowHeight = 40 
}

Upvotes: -1

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