警报，iOS，Swift的屏幕截图

Question

I am taking a screenshot when I show an alert, this works in taking a screenshot but when it is saved to the camera roll it has only captured the screen behind the alert and hasn't included the alert in the screenshot.

Is it possible to do this?

Below is my code.

func ScreenShot() {
    //Create the UIImage
    UIGraphicsBeginImageContextWithOptions(view.frame.size, true, 0)
    guard let context = UIGraphicsGetCurrentContext() else { return }
    view.layer.render(in: context)
    guard let image = UIGraphicsGetImageFromCurrentImageContext() else { return }
    UIGraphicsEndImageContext()

    //Save it to the camera roll
    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil)
}

caling it here.

func alertShow() {

    let alert = UIAlertController(title: "ALERT!!!", message: "Message stuff", preferredStyle: UIAlertControllerStyle.alert)


    alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: { action in

        self.performSegue(withIdentifier: "toMainInfoVC", sender: nil)

    }))

    self.present(alert, animated: true, completion: nil)
    ScreenShot()
}

Answer 1

I think you need the complete layer of the key window

let layer = UIApplication.shared.keyWindow!.layer
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale);

layer.render(in: UIGraphicsGetCurrentContext()!)

Answer 2

There are two problems with your code. First you are immediately trying to take a snapshot before the alert has finished being presented. You shoudl call your snapshot function in the compeletion handler of present:

self.present(alert, animated: true) { self.ScreenShot() }

Second you are only rendering the current view, and the alert is not a subview of your viewcontroller's view. You want to render the entire window hierarchy instead:

view.window?.layer.render(in: context)