lifecycle

问题 I have an application that reads values from a Database table (Database is named SoftCopyDatabase) and populates a List with the values read from Database. On clicking an item from the list a New Activity Starts. The problem is when I press the back key I got an error IllegalStateException: database already closed My code is as follows: public class OpenClick extends ListActivity { public static String subjectName; private SoftCopyDatabase lectures; private static int[] subTO = { R.id.subject

问题 Update: Actually, I have implemented "toggle menu" as on this doc.Please see that.The toggle menu is working fine.But I need to get the latest token when a user clicks the toggle menu.It works only with the constructor.After that, I cannot do that.That is may be due to the Root component.How can I achieve that? Ionic2 Toggle Menu Which life cycle event can I access after creating the app.component.ts component? First time it fires constructor() code.But after that none of the lifecycle events

问题 I've got 2 activities in a tabhost. In Activity1, I handle orientation changes and when the user switches between activities fine. The problem starts when the user switches from Activity1 to Activity2 (via tab select), performs an orientation change, then switches BACK to Activity1. I get a bit lost with the life cycle events that take place in my Activity1 while things are going when Activity2 is visible. According to the debugger, here's the sequence of events that occur in my Activity1: ==

问题 Android documentation talks about onStop an onDestroy couldn't be called in some circustances, but i didn't find nothing about the same with fragments. Is onPause, onStop, onDestroyView, on Destroy and onDetach always called? Only on Pause? 回答1: It's the same for Fragments , so only onPause is always called. Most of these callbacks are called at the same time (before or after to be exact) corresponding callbacks from Activity are called, when the fragment is added via xml layout. Note that on

问题 I'm new to this world and I need to understand some of the concepts of Backbone and Marionette. Here I'm trying to explain some of the concepts I'm learning. It would be great to having some feedback on them. The render function defines the logic for rendering a template. When it is finished, the onRender callback is called. Here I suppose the rendered view has been not attached to the DOM. It is composed by a tagName (the default is div ) that contains the template I attached to it. To

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . A good detailed tutorial on the lifecycle of a page request. I've read up on the ASP.NET page lifecycle, I am talking about things that happened before the .NET process starts to handle the request. i.e. domain typed into browser, DNS mapping? etc. 回答1: For Quick Reference: I use the following chart all the time

问题 I have an entity in Doctrine2 and use the HasLivecycleCallbacks with PrePersist. In general this works fine, but I would like to change the version only, when certain fields in my entity change. Do I have a chance to get the old Values? Or just the keys that have been changed? /** * @ORM\HasLifecycleCallbacks */ class Person { /** * @PrePersist * @PreUpdate */ public function increaseVersion() { if ( $this->version == null ) { $this->version = 0; } // only do this, when a certain attribute

问题 Please correct me if I'm wrong on any of this. This is a kind of clarifying question since I haven't seen it explicitly written anywhere. In Android 4, you can call setRetainInstance(true) on a Fragment so that on configuration changes (which basically means device rotation), the Fragment java object isn't destroyed and a new instance of it isn't created. That is, the instance is retained. This is much more sane and less infuriating than in Android 1-3 since you don't have to deal with

问题 By the document, "onPause" is called, when: when the system is about to start resuming a previous activity. Compared to "onStop", the difference is: Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. But when I long-press HW-Home key and the "recent apps" shows up, the "onPause" is not called. At this moment, I can no long able to interact with the original activity, but it is still visible. I am confused by this

问题 I understand pretty well about Android lifecycle. I post here because I've observed one weird behavior, anyway this is my own thought. My case is like this: One activity will use a simple layout with just a single EditText . In the activity onCreate method, i set some default text to the EditText and in later part of the method, assign a TextWatcher to the EditText so whenever user types in anything, i can response in my own way. Everything is alright until I rotate the screen. The