96 lines
3.1 KiB
Markdown
96 lines
3.1 KiB
Markdown
---
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title: View Controllers
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---
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## View Controllers
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This is an example of what a basic view in Swift looks like.
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```Swift
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import UIKit
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class ViewController: UIViewController {
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// 1
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override func viewDidLoad() {
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// 2
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super.viewDidLoad()
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// 3
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view.backgroundColor = .white
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}
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}
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```
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1. Loads view after the controller loads.
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2. Overrides the UIViewController class. This is a necessary step for any view controller.
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3. Sets background color to white.
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## Extending View Controllers
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Extensions can help keep your code clean when conforming to multiple protocols.
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This is an example of how you can add a TableView to a Basic View Controller.
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```Swift
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import UIKit
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class ViewController: UIViewController {
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// 1
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@IBOutlet weak var tableView: UITableView!
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// 2
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let data = ["New York, NY", "Los Angeles, CA", "Chicago, IL", "Houston, TX",
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"Philadelphia, PA", "Phoenix, AZ", "San Diego, CA", "San Antonio, TX",
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"Dallas, TX", "Detroit, MI", "San Jose, CA", "Indianapolis, IN",
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"Jacksonville, FL", "San Francisco, CA", "Columbus, OH", "Austin, TX",
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"Memphis, TN", "Baltimore, MD", "Charlotte, ND", "Fort Worth, TX"]
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override func viewDidLoad() {
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super.viewDidLoad()
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// 10
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tableView.dataSource = self
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// 11
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tableView.register(UITableViewCell.self, forCellReuseIdentifier: "myCellIdentifier")
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}
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}
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// 3
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extension ViewController: UITableViewDataSource {
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// 4
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func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
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// 5
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let cell = tableView.dequeueReusableCell(withIdentifier: "myCellIdentifier", for: indexPath)
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// 6
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cell.textLabel?.text = data[indexPath.row]
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// 7
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return cell
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}
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// 8
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func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
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// 9
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return data.count
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}
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}
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//12
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extension ViewController: UITableViewDelegate {
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//13
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func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
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//14
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}
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}
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```
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1. Define the outlet for our tableView
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2. Define the data that we'll be loading into our tableView
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3. Adds extension to ViewController class that conforms to UITableViewDataSource
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4. Implement the UITableViewDataSource stubs for required methods - cellForRowAt (defines what goes in a specific cell)
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5. Define a cell as a resuable element with the identifier "myCellIdentifier"
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6. Provide our cell's textLabel with the referenced data
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7. Return that cell
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8. Implement the UITableViewDataSource stubs for required methods - numberOfRowsInSection (defines how many rows will be in your tableView)
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9. Return the size of our data array
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10. Set the tableView's dataSource to self when the view loads
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11. register the tableView's cell
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12. Adds extension to ViewController class that conforms to UITableViewDelegate
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13. Implement UITableViewDelegate stub for method didSelectRowAt
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14. Add action when appropriate cell is selected
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