Question

我有一个类，这是我的模型，用于获取文本值和要显示的图像。

我试图将文本值和图像返回到控制器以在UILabel和ImageView上显示，但由于某些原因，我的函数不断生成错误，例如未指定返回类型或“初始化前使用了变量'image'”

有人可以告诉我编写此功能的最佳方法是什么吗？这两个数组将是固定的，并且将始终至少具有一个值。我也想知道如果数组可能为nil的话会怎样。

struct LoginCardSwipe{
    let loginText = ["Discover new and interesting people near by" , "Swipe Right to meet new" , "Hey how are you?", "Discover new and interesting people near by" , "Discover new ", " Heoosadda" ]

    let loginImage = ["tinder1", "tinder2", "tinder1", "tinder2", "tinder2"]
    var currentIndex = 0
    mutating func getCardValueRight() -> String{
        currentIndex += 1
        if currentIndex >= 0, currentIndex < loginText.count {
            let textValue = loginText[currentIndex]
            return textValue
        } else{
            return ""
        }
    }

    mutating func getCardImageRight() -> UIImage{
        currentIndex += 1
        var image: UIImage?
        if currentIndex >= 0, currentIndex < loginText.count {
            let cardImage = loginImage[currentIndex]
            image = UIImage(named: cardImage)
        }
        return image!
    }

    mutating func getCardValueLeft() -> String{
        currentIndex -= 1
        var textValue: String
        if currentIndex >= 0, currentIndex < loginText.count {
            textValue = loginText[currentIndex]
            return textValue
        }else{
            return ""
        }
    }

    mutating func getCardImageLeft() -> UIImage{
        currentIndex -= 1
        var image: UIImage
        if currentIndex >= 0, currentIndex < loginText.count {
            let cardImage = loginImage[currentIndex]
            image = UIImage(named: cardImage)!
        }

        return image
    }
}

Answer 1

两种左右图像方法的正确实现

mutating func getCardImageRight() -> UIImage? {
    currentIndex += 1
    if currentIndex >= 0, currentIndex < loginText.count {
        let cardImage = loginImage[currentIndex]
        return UIImage(named: cardImage)
    }
    return nil
}

//

mutating func getCardImageLeft() -> UIImage? {
    currentIndex -= 1
     if currentIndex >= 0, currentIndex < loginText.count {
        let cardImage = loginImage[currentIndex]
        return UIImage(named: cardImage)
    }

    return nil
}

//

以及使用时

if let left = strInstance.getCardImageLeft() {

}

强行使用-解开可能为nil的值将导致崩溃

如何在函数内返回UIImage？

1 个答案: