在iOS应用程序中查看主屏幕（Swift）

Question

如何使UIView半透明的背景，以便用户可以看到他们（模糊）的主屏幕？

如果这是不可能的，也许我可以截取主屏幕并添加半透明效果。在这种情况下，如何截取用户主屏幕的屏幕截图？

Apple有严格的隐私观点（我支持），所以我知道上述任何一项都不允许。

Answer 1

1. For having background of previous UIViewController, present next controller with presentationStyle as overFullScreen.

let vc = ViewController()
vc.modalPresentationStyle = .overFullScreen
self.present(vc, animated: true, completion: nil)

如果需要半透明效果使用，

let blurEffect = UIBlurEffect(style: UIBlurEffectStyle.dark)
blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
view.addSubview(blurEffectView)

2. To take screenshot.

func takeScreenshot(view: UIView) -> UIImageView {
     UIGraphicsBeginImageContext(view.frame.size)
     view.layer.render(in: UIGraphicsGetCurrentContext()!)
     let image = UIGraphicsGetImageFromCurrentImageContext()
     UIGraphicsEndImageContext()
     UIImageWriteToSavedPhotosAlbum(image!, nil, nil, nil)
     return UIImageView(image: image)   
}

let view = HomeScreen().view
let image = taketakeScreenshot(view)