ios程序启动顺序
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
print("application:构造函数")
return true
}
func applicationWillResignActive(_ application: UIApplication) {
print("applicationWillResignActive:程序即将取消激活状态")
}
func applicationDidEnterBackground(_ application: UIApplication) {
print("applicationDidEnterBackground:程序进入后台")
}
func applicationWillEnterForeground(_ application: UIApplication) {
print("applicationWillEnterForeground:程序即将进入前台")
}
func applicationDidBecomeActive(_ application: UIApplication) {
print("applicationDidBecomeActive:程序被激活");
view?.removeFromSuperview()
}
func applicationWillTerminate(_ application: UIApplication) {
print("applicationWillTerminate:程序关闭");
}
·启动程序时顺序：构造函数->程序被激活
程序启动.png
·进入切换程序界面（双击home键）执行：程序即将取消激活状态
切换界面.png
·从切换界面返回程序执行：程序被激活
·返回桌面（单击home键）执行顺序：程序即将取消激活状态->程序进入后台
返回桌面.png
·从桌面回到程序：程序即将进入前台->程序被激活
*例：如果想让app在进程切换界面不显示程序内容的话，可以在applicationWillResignActive的时候放一张图在覆盖window，然后在applicationDidBecomeActive的时候去掉
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
print("application:构造函数")
view = UIView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height))
view?.backgroundColor = UIColor.red
return true
}
func applicationWillResignActive(_ application: UIApplication) {
print("applicationWillResignActive:程序即将取消激活状态")
self.window?.addSubview(view!)
self.window?.bringSubview(toFront: view!)
}
func applicationDidBecomeActive(_ application: UIApplication) {
print("applicationDidBecomeActive:程序被激活");
view?.removeFromSuperview()
}
切换.gif
