I want to create a custom view that has a UITableView as a subview.
The custom view creates the table view programmatically. To the outside world (i.e., the ViewController), though, the custom view itself would appear to be a table view.
import UIKit
class CustomTableView: UIView {
// Do I make outlets?
//@IBOutlet var dataSource: UITableViewDataSource?
//@IBOutlet var delegate: UITableViewDelegate?
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(frame: CGRect){
super.init(frame: frame)
}
override func awakeFromNib() {
super.awakeFromNib()
}
override func layoutSubviews() {
super.layoutSubviews()
var tableView: UITableView!
tableView = UITableView(frame: self.bounds)
// I'm not sure how to set the delegate and dataSource
// tableView.dataSource = ???
// tableView.delegate = ???
self.addSubview(tableView)
}
}
After creating the UITableView programmatically and adding it as a subview to the custom view parent, I can't figure out how to get the custom view to act like it is the table view. That is, I don't know how to get the custom view to do the communication between the View Controller and the table view for the delegate
and dataSource
.
These articles seemed good, but I got a little lost.
How do I make the custom view act like it's own table subview with regard to delegate and data source?
There are two main base ways to populate a tableview. The more popular is through Interface Building, using a prototype cell UI object. The other is strictly through code when you don't need a prototype cell from Interface Builder.
For performance reasons, a table view's data source should generally reuse UITableViewCell objects when it assigns cells to rows in its tableView(_:cellForRowAt:) method. A table view maintains a queue or list of UITableViewCell objects that the data source has marked for reuse.
The solution is to make the tableView
a property of the custom class (as @BaseZen suggested). Then provide properties and methods in the custom class to mimic and pass along the properties and methods needed from tableView
.
import UIKit
@IBDesignable class UICustomTableView: UIView {
private var myTableView: UITableView
required init(coder aDecoder: NSCoder) {
myTableView = UITableView()
super.init(coder: aDecoder)
}
override init(frame: CGRect){
myTableView = UITableView()
super.init(frame: frame)
}
override func awakeFromNib() {
super.awakeFromNib()
}
// TODO: @IBOutlet still can't be set in IB
@IBOutlet weak var delegate: UITableViewDelegate? {
get {
return myTableView.delegate
}
set {
myTableView.delegate = newValue
}
}
// TODO: @IBOutlet still can't be set in IB
@IBOutlet weak var dataSource: UITableViewDataSource? {
get {
return myTableView.dataSource
}
set {
myTableView.dataSource = newValue
}
}
func registerClass(cellClass: AnyClass?, forCellReuseIdentifier identifier: String) {
myTableView.registerClass(cellClass, forCellReuseIdentifier: identifier)
}
func dequeueReusableCellWithIdentifier(identifier: String) -> UITableViewCell? {
return myTableView.dequeueReusableCellWithIdentifier(identifier)
}
override func layoutSubviews() {
super.layoutSubviews()
// ...
// setup UITableView
myTableView.frame = self.bounds
self.addSubview(myTableView)
// ...
}
}
Then it can be used like a normal UITableView
:
import UIKit
class TableViewDemoVC: UIViewController, UITableViewDelegate, UITableViewDataSource {
@IBOutlet weak var customTableView: UICustomTableView!
var items: [String] = ["One", "Two", "Three"]
override func viewDidLoad() {
super.viewDidLoad()
// setup the table view from the IB reference
customTableView.delegate = self
customTableView.dataSource = self
customTableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "cell")
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell: UITableViewCell = self.customTableView.dequeueReusableCellWithIdentifier("cell") as UITableViewCell!
cell.textLabel?.text = self.items[indexPath.row]
return cell
}
// ...
}
It's not the most elegant, but jump out a level:
class MyCustomViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
override func viewDidLoad() {
myCustomView = CustomTableView()
myCustomView.frame = ... /* layout programatically */
/* Alternatively to the above 2 lines,
lay out myCustomView in StoryBoard,
and capture it as an @IBOutlet. It will then be ready here
to muck with, well before it gets displayed and needs the data */
myCustomView.tableView.delegate = self
myCustomView.tableView.dataSource = self
}
/* Now implement all your dataSource and delegate methods */
}
* IMPORTANT *
The key that you're missing is that tableView
must be a stored property of your custom view. It's important and needs to be promoted from a silly local! It should also be initialized in the awakeFromNib() function, even if you don't know the frame size. Then reset its frame at layout time.
At a higher level, I don't know "What You're Really Trying To Do." It may not actually be the right implementation technique to be embedding a UITableView within a custom view; consider just laying out the UITableView in the main view. Then if you need decoration around it, lay those out as separate views in StoryBoard.
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