Question

我想根据变量更改图像，我不确定如何做到这一点。

我认为我的代码是正确的，但是在iOS模拟器中，图像只是空白。我想知道为什么？

以下是我的代码：

import UIKit

class BuyTicketViewController：UIViewController {

@IBOutlet weak var stadiumImage: UIImageView!
@IBOutlet weak var logoImage: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()

    if (globalVenueSelected == "Gillingham Football Club"){
        let imageGillinghmaFootballClub : UIImage = UIImage(named: "gillinghamStadium.jpg")!
        let stadiumImage = (image: imageGillinghmaFootballClub)

    }
    if (globalVenueSelected == "Old Trafford"){
        let imageOldTraffordFootballClub : UIImage = UIImage(named: "oldTraffordStadium.jpg")!
        let stadiumImage = (image: imageOldTraffordFootballClub)

    }
    if (globalVenueSelected == "Emirates Stadium"){
        let imageEmiratesFootballClub : UIImage = UIImage(named: "emiratesStadium.jpg")!
        let stadiumImage = (image: imageEmiratesFootballClub)

    }
    if (globalVenueSelected == "Wembley"){
        let imageWembley : UIImage = UIImage(named: "wemblyStadium.jpg")!
        let stadiumImage = (image: imageWembley)

    }
    if (globalVenueSelected == "O2 Arena"){
        let imageO2Arena : UIImage = UIImage(named: "o2ArenaStadium.jpg")!
        let stadiumImage = (image: imageO2Arena)
    }



}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/


}

哦，顺便说一句，变量globalVenueSelected是一个全局变量，我不知道它是否会影响任何东西，但它可能会改变代码。

感谢任何帮助，谢谢。

Answer 1

请尝试以下代码。

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

    var imageName: String!

    switch globalVenueSelected {
    case "Gillingham Football Club":
        imageName = "gillinghamStadium.jpg"

    case "Old Trafford":
        imageName = "oldTraffordStadium.jpg"

    case "Emirates Stadium":
        imageName = "emiratesStadium.jpg"

    case "Wembley":
        imageName = "wemblyStadium.jpg"

    case "O2 Arena":
        imageName = "o2ArenaStadium.jpg"

    default: break
    }

    self.stadiumImage.image = UIImage(named: imageName)
}

您应该将switch语句放在viewWillAppear(:)中，因为您的IBOutlet可能未在viewDidLoad中设置。

此外，许多人认为最佳做法是使用反映该变量类型的变量名称。例如，

stadiumImage应重命名为stadiumImageView。
同样，logoImage应重命名为logoImageView。

正确命名变量名称将使您和其他人更容易阅读，理解和维护您的代码。

此外，默认情况下，项目的资产目录通常不会接受.jpg个文件。您可以将体育场图片转换为.png格式，然后在设计时将其添加到资产目录中，或者您可以参考this Stack Overflow answer来解释如何让您的资产目录接受非PNG资源。

根据Swift xCode中的变量将UI Image更改为特定图像

1 个答案: