问题
I am trying to setup dynamic height for my custom table view cell...programatically.
There are many tutorials for doing it inside the storyboard, but this is about a pure programmatic solution:
class CustomTableViewCell: UITableViewCell {
var container: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func awakeFromNib() {
super.awakeFromNib()
self.setupView()
self.addConstraints()
}
func setupView() {
self.contentView.addSubview(self.container)
self.container.backgroundColor = UIColor.cyan
}
func addConstraints() {
self.container.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 0).isActive = true
self.container.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor, constant: 0).isActive = true
self.container.topAnchor.constraint(equalTo: self.contentView.topAnchor, constant: 0).isActive = true
self.container.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor, constant: 0).isActive = true
self.container.heightAnchor.constraint(equalToConstant: 200)
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
}
}
And my view where i am registering it:
class CustomViewController: UIViewController {
var data: [Post] = []
let tableview: UITableView = {
let tableview = UITableView()
tableview.translatesAutoresizingMaskIntoConstraints = false
return tableview
}()
override func viewDidLoad() {
super.viewDidLoad()
self.setupView()
self.addConstraints()
self.getData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func setupView() {
self.view.addSubview(self.tableview)
self.tableview.delegate = self
self.tableview.dataSource = self
self.tableview.register(UINib(nibName: "CustomTableViewCell", bundle: nil), forCellReuseIdentifier: "CellCustom")
self.tableview.estimatedRowHeight = 100
self.tableview.rowHeight = UITableViewAutomaticDimension
}
func addConstraints() {
self.tableview.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 40).isActive = true
self.tableview.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -40).isActive = true
self.tableview.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 40).isActive = true
self.tableview.bottomAnchor.constraint(equalTo: self.view.bottomAnchor, constant: -40).isActive = true
}
func getData() {
// some networking stuff
}
}
extension CustomViewController: UITableViewDelegate {
}
extension StreamViewController: UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CellCustom", for: indexPath) as! CustomTableViewCell
return cell
}
}
I am trying to just simply resize my custom tableview cell bases on its height constraint:
self.container.heightAnchor.constraint(equalToConstant: 200)
But this not work.. the custom tableview cell stays at "44"..
Anybody could tell me what is wrong with my pure programmtic solution?
Thanks and Greetings
回答1:
The problem seems to be that the height constraint is not active
func addConstraints() {
...
self.container.heightAnchor.constraint(equalToConstant: 200)
}
Thats why the UITableViewAutomaticDimension does not work.
Change it to self.container.heightAnchor.constraint(equalToConstant: 200).isActive = true and it should work
回答2:
Just dynamically calculate the height for each cell.
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 200
}
PS: It's better to save this height value, so you don't need to recalculate it over and over again.
来源：https://stackoverflow.com/questions/46165080/swift-3-custom-tableviewcell-dynamic-height-programatically