从UITableViewController更改为UITableView时发生错误

Question

I'm trying to embed a Table View in a regular View Controller because I want some other Views in the View Controller besides just the Table View. I had a Table View Controller with some methods that I was overriding. I copied the code for the Table View Controller, pasted it into a Table View .swift file, and removed the "override" before each method as the methods weren't inherent to the Table View class. Unfortunately I'm still getting errors in a few lines of the code:

1. super.viewDidLoad() "Value of type 'UITableView' has no member 'viewDidLoad'"

2. tableView.rowHeight = UITableViewAutomaticDimension "Ambiguous reference to member 'tableView(_:numberOfRowsInSection:)'"

3. tableView.estimatedRowHeight = 60.0 "Ambiguous reference to member 'tableView(_:numberOfRowsInSection:)'"

4. super.didReceiveMemoryWarning() "Value of type 'UITableView' has no member 'didReceiveMemoryWarning'"

5. tableView.insertRows(at: [indexPath], with: .automatic) "Ambiguous reference to member 'tableView(_:numberOfRowsInSection:)'"

What do I need to do to those lines of code to make my program run? It fails to build if I leave the code as it is, and if I put two slashes in front of those lines of code, it runs but just creates a black screen. Any help would be greatly appreciated! Thanks!

import UIKit

class TaskListTableView: UITableView {

var tasks:[Task] = taskData

func viewDidLoad() {
    super.viewDidLoad()
    tableView.rowHeight = UITableViewAutomaticDimension
    tableView.estimatedRowHeight = 60.0
}

func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return tasks.count
}

@IBAction func cancelToLoLFirstTableViewController(_ segue:UIStoryboardSegue) {
}

@IBAction func saveAddTask(_ segue:UIStoryboardSegue) {
    if let AddTaskTableViewController = segue.source as? AddTaskTableViewController {

        if let task = AddTaskTableViewController.task {
            tasks.append(task)

            let indexPath = IndexPath(row: tasks.count-1, section: 0)
            tableView.insertRows(at: [indexPath], with: .automatic)
        }
    }
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath)
    -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "TaskCell", for: indexPath)
            as! TaskCell


        let task = tasks[indexPath.row] as Task
        cell.task = task
        return cell
}

}

Answer 1

I think you are confused about what the UITableView and UITableViewController classes do.

A UITableView class is the class that draws the table view component you see on your screen, updates it when necessary and interprets your taps and scrolls into something that makes sense in terms of a table. UITableView extends UIView .

The UITableViewController class is designed to manage a UITableView instance, providing data to display and responding to the actions that it generates. It is an extension of the UIViewController class.

UIView and UIViewController are completely different things and perform completely different functions. You cannot cut and paste code from one to the other because they won't understand it.

So my first recommendation is to hit the books. Read up on what UIView and UIViewController 's do to get an understanding of their place in the iOS universe and how they relate to each other. Then look at UITableView and UITableViewController .

Secondly, as to your problem of wanting to have a screen with a table view as well as other components. There are multiple ways to do this and the best solution will vary depending on the complexity of the UI you are trying to build and the data and code behind it.

Once you've got your head around how views and controllers work. I would start by building a simple screen with several simple components on it and a single controller behind it. ie. A class you have written that extends UIViewController .

When your happy with this, you have two choices that I typically see:

1. You can add a UITableView UI component and set your UITableViewController as it's dataSource <UITableViewDataSource> and delegate <UITableViewDelegate> . Then add in the various methods from these protocols to define the data to display and how your controller will respond to your actions on the table view.

2. A more complex choice you should look at if #1 gets too messy. This choice can result in cleaner code. Instead of adding the UITableView UI component, you add a UIContainerView UI component. UIContainerView s are designed to link to a seperate controller and view. Effectively this means you have two controllers. One for the general UI components and one for the table view.

This is all going to depend on exactly what you are trying to do. But first you need to do some reading.