CODEWITHSUNDEEP
iosswift
Ai Nguyen
Ai Nguyen

Reputation: 41

Cannot express tuple conversion with UIImage

I try to set the theme (include the background and a picture) for my app. I try this code:

import UIKit

enum AppTheme {
    case dayMode
    case nightMode

    func setBackground() -> (UIImage, UIImage) {
        switch self {

        case .dayMode():
            let backgroundImage = #imageLiteral(resourceName: "DayMode")
            let sunControllerImage = #imageLiteral(resourceName: "sun")
            return (backgroundImage, sunControllerImage)

        case .nightMode():
            let backgroundImage = #imageLiteral(resourceName: "NightMode")
            let sunControllerImage = #imageLiteral(resourceName: "moon")
            return (backgroundImage, sunControllerImage)

        }
    }
}

then in viewDidLoad, I try:

override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        (backgroundImg.image, sunControllerImg.image) = AppTheme.nightMode.setBackground()

    }

However, there is an error:

Cannot express tuple conversion (UIImage, UIImage) to (UIImage?, UIImage?) (aka (Optional<UIImage>, Optional<UIImage>)).

Is there anyway to handle this?

Upvotes: 0

Views: 233

Answers (1)

Nazmul Hasan
Nazmul Hasan

Reputation: 10590

try this way 

enum AppTheme {
    case dayMode
    case nightMode

    func setBackground() -> (UIImage?, UIImage?) {
        switch self {

        case .dayMode():
            let backgroundImage = #imageLiteral(resourceName: "DayMode")
            let sunControllerImage = #imageLiteral(resourceName: "sun")
            return (backgroundImage, sunControllerImage)

        case .nightMode():
            let backgroundImage = #imageLiteral(resourceName: "NightMode")
            let sunControllerImage = #imageLiteral(resourceName: "moon")
            return (backgroundImage, sunControllerImage)

        }
    }
}

cause UIImage is Optional .

Swift have a concept of failable initializers and UIImage is have of them. The initializer returns an Optional so if the image cannot be created it will return nil.

Upvotes: 1

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