助理编辑器显示不同的“ViewController.swift"文件比主编辑器显示的文件?

辅助编辑器中显示的ViewController.swift"源代码与主编辑器中显示的ViewController.swift"源代码不同.

The source code shown in the Assistant Editor for "ViewController.swift" is different than source code shown in Main Editor for "ViewController.swift".

主编辑器中的ViewController.swift":

"ViewController.swift" in Main Editor:

//  ViewController.swift
//  FoodTracker

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {
    // MARK: Properties
    @IBOutlet weak var nameTextField: UITextField!
    @IBOutlet weak var mealNameLabel: UILabel!
    @IBOutlet weak var mainButton: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        nameTextField.delegate = self
    }

    // MARK: UITextFieldDelegate
    func textFieldShouldReturn(textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }

    func textFieldDidEndEditing(textField: UITextField) {
        mealNameLabel.text = textField.text
    }

    // MARK: Actions
    @IBAction func setDefaultLabelText(sender: UIButton) {
        mealNameLabel.text = "DEFAULT text"
        // mainButton.tintColor = UIColor.darkTextColor()    
    } 
}

Assistant Editor 中的ViewController.swift":

"ViewController.swift" in Assistant Editor:

//
//  ViewController.swift
//  FoodTracker
import UIKit

internal class ViewController : UIViewController, UITextFieldDelegate {

    @IBOutlet weak internal var nameTextField: UITextField!
    @IBOutlet weak internal var mealNameLabel: UILabel!
    @IBOutlet weak var mainButton: UIButton!

    override internal func viewDidLoad()

    internal func textFieldShouldReturn(textField: UITextField) -> <<error type>>

    internal func textFieldDidEndEditing(textField: UITextField) -> <<error type>>

    @IBAction internal func setDefaultLabelText(sender: UIButton) -> <<error type>>
}

所以，这些是完全不同的不同文件，但具有相同的名称.Assistant Editor中的那个是interface，而Main Editor中显示的文件是接口的实现，对吧?

So, those are completely different different files, but have the same name. The one in the Assistant Editor is the interface while the file shown in the Main Editor is the implementation of the interface, right?

这看起来有点奇怪，但是接口和实现类同名?当我在 Xcode 中工作时，我需要注意有时两个文件可以(通常?)具有相同的名称?

That seems a little weird, but the interface and implementing class have the same name? When I'm working in Xcode I need to be aware that sometimes two files can (often?) have the same name?