Swift：如何在ViewController中跨XIB文件访问IBOutlet并实现交互

Hey there! Since you're new to Swift, let's break this down simply. The main issue right now is that your addUIView2 is a local variable inside viewDidLoad—so your button action method can't access it. Here's how to fix this step by step:

Step 1: Add properties for your XIB views to the ViewController #

First, declare two properties at the top of your ViewController class, so they're accessible throughout the class:

class ViewController: UIViewController {
    // Properties to hold references to your XIB-based views
    private var totalOzView: totalOZVC?
    private var glassSelectorView: GlassSelectorVC?
    
    // Rest of your class code...
}

Step 2: Update viewDidLoad to assign these properties #

Modify your viewDidLoad method to store the loaded XIB views in the class properties instead of using local variables:

override func viewDidLoad() {
    super.viewDidLoad()
    
    // Load and configure totalOz view
    if let loadedTotalOzView = Bundle.main.loadNibNamed("totalOz", owner: self, options: nil)?.first as? totalOZVC {
        totalOzView = loadedTotalOzView
        self.view.addSubview(loadedTotalOzView)
        // Attach button action
        loadedTotalOzView.button120ml.addTarget(self, action: #selector(buttonSelectGlassSize(sender:)), for: .touchUpInside)
    }
    
    // Load and configure GlassSelector view
    if let loadedGlassSelectorView = Bundle.main.loadNibNamed("GlassSelector", owner: self, options: nil)?.first as? GlassSelectorVC {
        glassSelectorView = loadedGlassSelectorView
        self.view.addSubview(loadedGlassSelectorView)
        loadedGlassSelectorView.labelGlassSelect.textColor = .white
        loadedGlassSelectorView.labelGlassSelect.text = "Select the size of Glass"
    }
}

Step 3: Update the button action to modify the label #

Now you can access the glassSelectorView property in your button action method to update the label's text:

@objc func buttonSelectGlassSize(sender: UIButton) {
    // Change the label text when the button is tapped
    glassSelectorView?.labelGlassSelect.text = "120mL Glass Selected!"
}

Quick Checks to Avoid Issues: #

• Double-check that in your totalOZVC XIB file, the button is properly connected to the button120ml outlet (Ctrl-drag from button to the code).
• Make sure GlassSelectorVC's XIB has the label connected to labelGlassSelect outlet the same way.
• The optional (?) on our properties and in the button action is safe—it prevents crashes if the XIB fails to load for any reason.

内容的提问来源于stack exchange，提问作者Saad Sikandar