Question

我想根据信标的接近程度更改应用程序的背景图像。如果我在iPhone上运行该应用程序（请参见下面的代码），则它会根据接近程度正确显示背景图片-但是，如果我移动，它不会更改/刷新背景图片。我尝试使用背景色进行相同操作（请参见下面的代码），并且可以正常工作：该应用程序根据信标的接近程度更改其背景色，并且如果我正确移动它，则可以更改/刷新背景色。只是背景图片无法正常工作。

如何强制背景图像正确刷新？

func updateDistance(_ distance: CLProximity) {
    UIView.animate(withDuration: 0.8) {
        switch distance {
        case .unknown:
            let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
            backgroundImage.image = UIImage(named: "1.jpg")
            //backgroundImage.reloadInputViews()
            backgroundImage.contentMode = UIView.ContentMode.scaleAspectFill
            self.view.insertSubview(backgroundImage, at: 0)
        //print("nothing here..")
        case .far:
            let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
            //backgroundImage.image = UIImage(named: "2.png")
            backgroundImage.image = UIImage(named: "3.png")
            //backgroundImage.reloadInputViews()
            backgroundImage.contentMode = UIView.ContentMode.scaleAspectFill
            self.view.insertSubview(backgroundImage, at: 0)
        case .near:
            let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
            backgroundImage.image = UIImage(named: "4.png")
            //backgroundImage.reloadInputViews()
            backgroundImage.contentMode = UIView.ContentMode.scaleAspectFill
            self.view.insertSubview(backgroundImage, at: 0)
        case .immediate:
            let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
            backgroundImage.image = UIImage(named: "5.jpg")
            //backgroundImage.reloadInputViews()
            backgroundImage.contentMode = UIView.ContentMode.scaleAspectFill
            self.view.insertSubview(backgroundImage, at: 0)
        @unknown default:
            // fatalError()
            let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
            backgroundImage.image = UIImage(named: "6.jpg")
            //backgroundImage.reloadInputViews()
            backgroundImage.contentMode = UIView.ContentMode.scaleAspectFill
            self.view.insertSubview(backgroundImage, at: 0)
        }
    }





func updateDistance(_ distance: CLProximity) {
    UIView.animate(withDuration: 0.8) {
        switch distance {
        case .unknown:
            self.view.backgroundColor = UIColor.gray
            print("nothing here..")
        case .far:
            self.view.backgroundColor = UIColor.blue
        case .near:
            self.view.backgroundColor = UIColor.orange
        case .immediate:
            self.view.backgroundColor = UIColor.red
//          self.sendUserNotification()
        @unknown default:
            <#fatalError()#>
        }
    }
}

Answer 1

您要以零索引插入所有图像，首先删除上一张图像，就好像它包含任何图像一样，例如在接近度之间切换会插入许多全部为零的图像，最后一张将出现。或者只是将其添加为子视图并显示在前面（如果需要），而不是插入零。
- 颜色有效，因为您查看的颜色只有一种。图像一一追加。为了更好地理解，请尝试查看调试。

如何根据信标的距离刷新背景图像？

1 个答案: