lifecycle

问题 I have a service that uses media player to play some music. The service is started by an activity and if something is playing and the user moves away from the activity the service should keep playing in the background. Running the service in the foreground seems to work (I can see the notification), but in close to all cases the service is destroyed immediately (OnDestroy called by the system on the service). I know using startForeground does not mean that the service is never killed, but it

问题 Is there any difference between those 2 functions? (besides their arguments) It seems like those methods have the same triggers, isn't it? Appreciate your help :) 回答1: componentDidUpdate is called whenever the component has re-rendered, which might be caused by either: a change in state a call to forceUpdate a parent component re-rendering (or another call to React.render in the case of the top-level component) The setState callback will only be called once the state transition has completed

问题 Observing my application behavior in Android emulator, I see that EditText contents is preserved after changing screen orientation (Ctrl+F11). But TextView contents is reset to its initial value and doesn't keep latest information set by the program. Is this behavior by definition? What can I do to keep this contents? 回答1: Use this property in your TextView android:freezesText="true" . 回答2: You can use the savedInstanceBundle to keep hold of the data by overriding two methods inside your

问题 I am using MvvmCross v3.5 to build an iOS application. Whenever the application goes into the background I am expecteing SaveState to be called in the view model. However it never gets called. I have tried this both on the simulator and a device. Am I missing something. This works in the Android version of the app, so I think I have set it up correctly. Has anyone else got this issue? Any help would be appreciated. 回答1: I think in Xamarin you need to implement UIApplicationDelegate

问题 I created a new ionic 3 project. In my HomePage , i have only one varible and one function: count = 0; printLog() { console.log("count", ++this.count); } In template home.html i call this function by interpolation binding: {{printLog()}} It is my whole code. In the console i see the log: As we can see the printLog function were called 9 times. I can't understand why. Can someone tell me why and how does it work? Many thanks! 来源： https://stackoverflow.com/questions/44402257/ionic3-angular2

问题 I am having some problems updating to the right value. On the page which you can see part of down under, there is a parameter 'change'. I think that this parameter is causing jsf to update the backing bean with the old value and thus do nothing. <h:panelGroup id="panel0"> <h:form id="changeForm"> <h:messages/> <!--This retains the parameter "change"--> <input type="hidden" name="change" value="#{param.change}"/> <!--CHANGE NAME--> <h:panelGrid id="panel1" rendered="#{param.change == 'name'}"

问题 My application on boot opens FirstActivity. From FirstActivity I can start: SecondActivity, ThirdActivity. When I press the Home button and then return to my app, it always opens FirstActivity, rather than opening the last activity (after returning start FirstActivity with onCreate() ). How I can restore application state on last activity? In code I don't start FirstActivity. My manifest: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res

问题 I got two pages: HomePage AboutPage HomePage is the rootPage . At startup HomePage#ionViewDidLoad is called. I navigate from the HomePage to the AboutPage using the NavController: navigateToAbout(): void { this.navCtrl.push('AboutPage'); } Everytime I navigate to the AboutPage, AboutPage#ionViewDidLoad is called. If I navigate back to the HomePage with ion-navbar , HomePage#ionViewDidLoad is not called but if I use navCtrl.push('HomePage') , HomePage#ionViewDidLoad is called again. Can

问题 I am using android studio,and the dependencies in build.gradle is here implementation 'android.arch.lifecycle:runtime:1.1.1' implementation 'android.arch.lifecycle:extensions:1.1.1' implementation 'android.arch.lifecycle:reactivestreams:1.1.1' annotationProcessor "android.arch.lifecycle:compiler:1.1.1" and here is the function i'm using private Single<MediaStream> getMediaStream() { Single<MediaStream> single = RxHelper.single(MediaStream. getBindedMediaStream(this, this), mediaStream); if

问题 I am using an ActivityGroup to spawn multiple activities and switch views from within the same tab in a TabActivity. When I press the back key this method is called inside my ActivityGroup public void back() { if(history.size() > 0) { history.remove(history.size()-1); if (history.size() > 0) setContentView(history.get(history.size()-1)); else initView(); }else { finish(); } } this method allows me to keep a stack of my activities and go back to the previous one when the back key is pressed.