Xcode 9 Swift 4 UITableView unrecognized selector sent to instance - ios

Question

I just moved from obj-c to swift and i am having problem with the UITableView inside a UIViewController
I have set the delegate and data source from the Interface Builder from the TableView to the View Controller, but it doesn't work fine
here is the screenshot
and here is my view controller
class SideMenuViewController: UIViewController {
#IBOutlet var tableView: UITableView!
var cellRow = ["Item 1","Item 2","Item 3"]
// MARK: - TableView Delegates
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cellRow.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let object = cellRow[indexPath.row]
cell.textLabel!.text = object.description
return cell
}
Here is the error
reason: '-[MyApp.SideMenuViewController tableView:numberOfRowsInSection:]: unrecognized selector sent to instance
However, if i set the delegate and data source manually by using code inside the view controller, it will work. Is it a bug??
Thanks

Answer 1

You must add UITableViewDelegate, UITableViewDataSource. Delegate class have to tell compiler that we are adopting the protocol and then implement the delegate method(s).
class SideMenuViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
// ...
}
Another good looking way is to implement protocols and delegates is by using extension.
class SideMenuViewController: UIViewController {
// ..
}
extension SideMenuViewController : UITableViewDelegate {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let object = cellRow[indexPath.row]
cell.textLabel!.text = object.description
return cell
}
}
extension SideMenuViewController : UITableViewDataSource {
func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return cellRow.count
}
}

Answer 2

Swift 4
You can just add delegate like this
Step 1 : class ViewController: VVBaseViewController, UITableViewDelegate, UITableViewDataSource
Step 2 Implement Delegate And DataSource Method
// MARK: - UITableViewDelegate, UITableViewDataSource
func numberOfSections(in tableView: UITableView) -> Int {
return 20 // Here is 20 section in tableview and 1 row each section.
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 1 // Only 1 row in each section
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Normal Cell (UITableViewCell)
// let cell:UITableViewCell = (tblProperty!.dequeueReusableCell(withIdentifier: cellReuseIdentifier) as UITableViewCell?)!
// Custom Cell
let cell:CellSubService = tblSubServices.dequeueReusableCell(withIdentifier: cellReuseIdentifier) as! CellSubService
cell.lblServiceName.text = "Test Service"
cell.lblRate.text = "$5 / Sq.Ft"
return cell
}