lifecycle

问题 I'd like to know how before I render a page, I want to send an async GET request to my server to retrieve data and populate the properties in data. I heard the best way to do this is to call the function that sends this request in one of the three lifecycle hooks Vue js offers that operate before the DOM is rendered. The three are beforeCreate() , created() , beforeMount() . Which one must this request be called in ideally? And why? 回答1: Vue's initialization code is executed synchronously.

问题 I basically have a App which renders a small map. On this page is also a "toggle" button which hides the small map with a *ngIf in the parent component and displays the map in large instead. If I now import BrowserAnimationsModule in app.module.ts the large map is not rendered if I click on the toggle button (only if i set a timeout of 1ms before the map is created in ngOnInit of map-base.component.ts). Sorry..it's a bit hard to explain, here's the code: App.module.ts ... @NgModule({

问题 I have a page containing a control called PhoneInfo.ascx. PhoneInfo is dynamically created using LoadControl() and then the initControl() function is called passing in an initialization object to set some initial textbox values within PhoneInfo. The user then changes these values and hits a submit button on the page which is wired up to the "submit_click" event. This event invokes the GetPhone() function within PhoneInfo. The returned value has all of the new user entered values except that

问题 I can't find the Application's object (extend Application) life cycle. For example, what happens if I have a broadcast receiver which is called through Alarm. Will methods in Application being called? Or is everything independent from the Application? If I have a datahelper instantiated in the Application and I call it from broadcast receiver, will it available? Which is the Application object life cycle, when it is destroyed? when is it called when using Alarms? What happens when the

问题 I'm getting an error message due to an async method issue. In my terminal I'm seeing: Warning: Can't call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method. - node_modules/fbjs/lib/warning.js:33:20 in printWarning - node_modules/fbjs/lib/warning.js:57:25 in warning - node_modules/react-native/Libraries/Renderer/ReactNativeRenderer

问题 I have recently migrated some of my projects to the shiny new Flex 4.6 SDK. I wasn't expecting much trouble since it was only a minor release. But as a matter of fact I got hundreds of errors all over the place. These errors would mostly come from Spark SkinnableComponent s; for example: override protected function getCurrentSkinState():String { return mySkinPart.someProperty ? "normal" : "someOtherState"; } would work just fine under 4.5, but would throw me a nullpointer error in 4.6. The

问题 My end-goal is to have an application that runs a block of code when it (the application, not the activity) is opened up after being left ( back from home screen, etc... ) According to the Activity Lifecycle, this should be the onRestart() event on a per activity basis ( at least how I interpret it ) Both onRestart() and onResume() are being called whether I am returning to the Activity within the application (back button) AND when the app is called back up. Given this diagram I am

问题 I really get confused with Fragment lifecycle, especially for the time to call getActivity() . Sometimes you cannot get Activity by getActivity() . And it always caused some puzzling bugs. Thank you for anyone can solve the puzzle. 回答1: getActivity() can be null while your fragment is in process of preparation and about to be ready. The fragment life cycle is bound to callback methods. These method will be called somewhere in time while fragment is preparing. Fragment.onActivityCreated(Bundle

问题 How to prevent an activity from being recreated on turning screen off? What I do Start Bejewels and go to the jewelry screen. Press power button shortly. The screen is turned off, but the device is not. Press power button again. What I see The same screen as before turning screen off. In case of my application (trivial one, just a web-app with a single WebView) the scenario is the following: What I do Start my app. The activity onCreate() method loads an URL into the WebView. Press power

问题 is there any way to know the state of my application if it is in background mode or in foreground . Thanks 回答1: [UIApplication sharedApplication].applicationState will return current state of applications such as: UIApplicationStateActive UIApplicationStateInactive UIApplicationStateBackground or if you want to access via notification see UIApplicationDidBecomeActiveNotification Swift 3+ let state = UIApplication.shared.applicationState if state == .background || state == .inactive { //