state | 易学教程

android button setPressed after onClick

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问题 yesterday I noticed the possibility to integrate Fragments in older API Levels through the Compatibility package, but thats not really essential for the question. :) I have a Button with an OnClickListener Button button = (Button) findViewById(R.id.button); button.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { doSomething(); button.setPressed(true); } }); Because of the actual clicking, it is shown as pressed and after releasing the click, the button state

what does it mean when they say http is stateless

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I am studing java for web and it mentions http is stateless. what does that mean and how it effects the programming I was also studying the spring framework and there it mentions some beans have to declared as inner beans as their state changes . What does that means? HTTP -- that is the actual transport protocol between the server and the client -- is "stateless" because it remembers nothing between invocations. EVERY resource that is accessed via HTTP is a single request with no threaded connection between them. If you load a web page with an HTML file that within it contains three <img>

Vuex state on page refresh

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问题 My app uses the Firebase API for User Authentication, saving the Login status as a boolean value in a Vuex State. When the user logs in I set the login status and conditionally display the Login/Logout button accordingly. But when the page is refreshed, the state of the vue app is lost and reset to default This causes a problem as even when the user is logged in and the page is refreshed the login status is set back to false and the login button is displayed instead of logout button even

Detecting outgoing call and call hangup event in android

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问题 I have a requirement wherein I want to detect two kind of events related to Calls in Android Whenever an outgoing call is made, my application should get to know this along with the called number When the call is hanged up(due to success/failure), my application should get to know this along with the reason of hangup Is this possible in Android? 回答1: You should create a BroadcastReceiver: public class CallReciever extends BroadcastReceiver { @Override public void onReceive(Context context,

Resetting the State of a Stream

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问题 I have a question which is slightly similar to this question on stackoverflow std::cin.clear() fails to restore input stream in a good state, but the answer provided there does not work for me. The question is: how can I reset the state of a stream to 'good' again? Here is my code how I try it, but the state is never set to good again. I used both of the lines ignore separately. int _tmain(int argc, _TCHAR* argv[]) { int result; while ( std::cin.good() ) { std::cout << "Choose a number: ";

Updating an object with setState in React

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Is it at all possible to update object's properties with setState? Something like: this.state = { jasper: { name: 'jasper', age: 28 }, } I have tried: this.setState({jasper.name: 'someOtherName'}); and this: this.setState({jasper: {name: 'someothername'}}) The first results in a syntax error and the second just does nothing. Any ideas? There are multiple ways of doing this, since state update is a async operation , so to update the state object, we need to use updater function with setState . 1- Simplest one: First create a copy of jasper then do the changes in that: this.setState(prevState =>

Maintain state of a dynamic list of checkboxes in ASP.NET MVC

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问题 I have a class called "PropertyFeature" which simply contains PropertyFeatureID and Description. It's a proper model created through LINQ to SQL mapped to an SQL Server database table. An example instance/row would be: PropertyFeatureID: 2 Description: "Swimming Pool" The number of rows (PropertyFeatures) can of course grow and shrink, and so I want to dynamically render a list of checkboxes so that the user can select any of them. I can dynamically render the Checkboxes easily enough, with

Handling standby on iPad using Javascript

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问题 Regarding iPad events, how to determine if/when the iPad is changing from an awake state to a standby state? What I would like to do is put my Mobile-Safari web app in a locked state whenever the iPad becomes inactive/standby and ask for a PIN when it becomes awake again. 回答1: I agree that there really ought to be some signal you can hook on to to know when an application goes to sleep and when it wakes up, but you should be able to figure out when Safari wakes up indirectly. When the webview

In javascript, how can I uniquely identify one browser window from another which are under the same cookiedbased sessionId

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问题 The users of my web application may have more than one browser window open and pointed to the same page. I would like the state of certain things in the page (loaded via ajax) to be retained across postbacks. I can either store in a cookie or on my server. Either way, I can't think of how I can distinguish each window. For example, say user Bob has two browser windows open to the ListOfSomething page. Each list has a LoadedPageNumber attribute which I need to persist. Otherwise users always

Does React keep the order for state updates?

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I know that React may perform state updates asynchronously and in batch for performance optimization. Therefore you can never trust the state to be updated after having called setState . But can you trust React to update the state in the same order as setState is called for the same component? different components? Consider clicking the button in the following examples: 1. Is there ever a possibility that a is false and b is true for: class Container extends React.Component { constructor(props) { super(props); this.state = { a: false, b: false }; } render() { return <Button onClick={this