在 Swift 5 中的 applicationWillResignActive 中显示图像

Question

所以，当应用程序进入后台时，我试图在最近的屏幕上显示图像。我已经实现了模糊效果，但我想用自定义背景白色的图像替换模糊效果。我不确定，在项目中的什么地方添加图像以及如何使用它。

import UIKit
import Flutter
import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  let TAG_BLUR_VIEW = 12345
  var blurView:UIVisualEffectView?
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FirebaseApp.configure()
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
  override func applicationWillResignActive(_ application: UIApplication) {
    if let view = self.window.rootViewController?.view.subviews.first(where: {[=11=].tag == TAG_BLUR_VIEW}){
        view.removeFromSuperview()
        blurView = nil
    }
    if blurView == nil{
        blurView = UIVisualEffectView(frame: UIScreen.main.bounds)
        blurView?.effect = UIBlurEffect(style: .light)
        blurView?.tag = TAG_BLUR_VIEW
    }
    self.window.rootViewController?.view.insertSubview(blurView!, at: 0)

  }


override func applicationDidBecomeActive(_ application: UIApplication) {
    if let view = self.window.rootViewController?.view.subviews.first(where: {[=11=].tag == TAG_BLUR_VIEW}){
        view.removeFromSuperview()
        blurView = nil
    }
  
}
}

仅供参考：这是一个 flutter 项目，我将为此功能进行本地化。所以这里总共 swift 个新手。

Answer 1

import UIKit
import Flutter
import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  // this tag can be any number. This tag will get assingned to the blurView, 
  // This tag will be used to removed the blur, when the app is in foreground.
  let TAG_BLUR_VIEW = 12345
  var blurView:UIImageView?
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FirebaseApp.configure()
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
  override func applicationWillResignActive(_ application: UIApplication) {
   let centerPos = self.window?.rootViewController?.view.center ?? .zero
   if let view = self.window.rootViewController?.view.subviews.first(where: {[=10=].tag == TAG_BLUR_VIEW}){
       view.removeFromSuperview()
       blurView = nil
   }
    if blurView == nil{
        blurView = UIImageView(image: UIImage(named: "secure.jpg")) //replace your image
        blurView?.backgroundColor = UIColor .white
        blurView?.tag = TAG_BLUR_VIEW
        blurView?.center = centerPos
    }
    // The bulr screen with the tag "12345" is added to the index 0
    self.window.rootViewController?.view.insertSubview(blurView!, at: 0)

  }

  // if the tag on the index 0, matches our blur tag, it removes the blur once the app is on foreground.
  override func applicationDidBecomeActive(_ application: UIApplication) {
    if let view = self.window.rootViewController?.view.subviews.first(where: {[=10=].tag == TAG_BLUR_VIEW}){
        view.removeFromSuperview()
        blurView = nil
    }
  
}
}

在 Swift 5 中的 applicationWillResignActive 中显示图像

Show an Image in applicationWillResignActive in Swift 5

swift

flutter

swift5