lifecycle

问题 i've overloaded the Application class in my android app and i'm using the ACRA report system. My app looks like ( real source code here ) : public class MyApplication extends Application { @Override public void onCreate() { ACRA.init( this ); /* * Initialize my singletons etc * ... * ... */ super.onCreate(); } } And as far as i know, the Application object should be created only once, so the onCreate method should be called only once. The problem is, that in my crash reports ( from ACRA ) i

问题 I am new to android development and I am programming a game. My game has cutsceens that play before each level starts, cutsceens which are done through videoview. My problem is, that upon an application pause, the cutsceen starts from the beginning again when resumed. @Override public void onPause() { super.onPause(); video.pause(); } @Override public void onResume() { super.onResume(); video.resume(); } Our issue is that the video doesn't actually resume from where we paused it, but from the

问题 I used Toast to make notification, but it seems it will appear even its activity is not in the current screen and some other activity has been started. I want to check this situation, when the activity is not the current one, I'd not send the Toast notification. But how to do ? 回答1: When your Activity comes to the foreground, its onResume() method will be invoked. When another Activity comes in front of your Activity, its onPause() method will be invoked. So all you need to do is implement a

问题 I used Toast to make notification, but it seems it will appear even its activity is not in the current screen and some other activity has been started. I want to check this situation, when the activity is not the current one, I'd not send the Toast notification. But how to do ? 回答1: When your Activity comes to the foreground, its onResume() method will be invoked. When another Activity comes in front of your Activity, its onPause() method will be invoked. So all you need to do is implement a

问题 The android app I am working on overrides the Application class to store lightweight state (username, gps location, etc) in static vars. Most of this state is set in OnCreate of the launch activity (username retrieved from prefs, location listener runs). Is it safe to rely on the launch activity to initialize the Application class? Are there any cases where the Application class might be re-created without the Launch activity also being created? The question comes up because I ran into a null

问题 I want to develop a module control system so that every spring bean can be managed by my own LifeCycle Controller. But I can not figure out how can I remove a singleton spring bean out of ApplicationContext. That may be an interesting problem , can you help me to resolve ? 回答1: You can try removing the bean definition. Get the BeanDefinitionRegistry and call removeDefinition(..) It depends on the way you create your application, but for example in web application you can get the definition

问题 I want to develop a module control system so that every spring bean can be managed by my own LifeCycle Controller. But I can not figure out how can I remove a singleton spring bean out of ApplicationContext. That may be an interesting problem , can you help me to resolve ? 回答1: You can try removing the bean definition. Get the BeanDefinitionRegistry and call removeDefinition(..) It depends on the way you create your application, but for example in web application you can get the definition

问题 I want to know if user would return to the home screen if he exit the current activity. 回答1: UPDATE (Jul 2015): Since getRunningTasks() get deprecated, from API 21 it's better to follow raukodraug answer or Ed Burnette one (I would prefer second one). There's possibility to check current tasks and their stack using ActivityManager. So, to determine if an activity is the last one: request android.permission.GET_TASKS permissions in the manifest. Use the following code: ActivityManager mngr =

问题 What exactly componentWillReceiveProps and getDerivedStateFromProps are subtle question for me. Because, I just came across to an issue while using getDerivedStateFromProps: // Component state = { myState: [] } // Using this method works fine: componentWillReceiveProps(nextProps) { this.setState({ myState: nextProps.myPropsState }) } // But using this method will cause the checkboxes to be readonly: static getDerivedStateFromProps(nextProps,prevProps) { const { myPropsState: myState } =

问题 I just developed a screen saver app and I found a strange behavior in its lifecycle. My work flow is like this: start my RegisterService , where I call registerReceiver method to register a BroadcastReceiver , which can receive ACTION_SCREEN_OFF . 2.In the onReceive method of this BroadcastReceiver , I start an activity as the screensaver. 3.In the activity, I write Log.i() statement to track its running. My question is: When the screen times out, or when I press the POWER key, the screen