state

问题 I need to install vagrant in headless ubuntu(Ubuntu 12.04.2 LTS- 64 Bit).Vagrant ver-v1.3.0 and Virtual box- 4.2.18. After adding the vagrant package box, when I am giving "vagrant up" command, am getting the following error: Bringing machine 'default' up with 'virtualbox' provider... [default] Clearing any previously set forwarded ports... [default] Creating shared folders metadata... [default] Clearing any previously set network interfaces... [default] Preparing network interfaces based on

问题 I wonder how to add state to the chain of decorators that will be available to the consumer. Given this simplified model: abstract class AbstractPizza { public abstract print(...); } class Pizza : AbstractPizza { public int Size { get; set; } public print(...); } abstract class AbstractPizzaDecorator { public Pizza:AbstractPizza; public abstract print(); } class HotPizzaDecorator : AbstractPizzaDecorator { public int Hotness { get; set; } public print(...); } class CheesyPizzaDecorator :

问题 I just read an article that describes how HttpApplicationState has AcquireRead() / AcquireWrite() functions to manage concurrent access. It continues to explain, that in some conditions however we need to use an explict Lock() and Unlock() on the Application object to avoid a Race condition. I am unable to understand why a race condition should exist for Application state if concurrent access is implicitly handled by the object. Could someone please explain this to me ? Why would I ever need

问题 I'm building a very primitive quiz app with ReactJS and I'm having trouble updating the state of my Questions component. Its behavior is it renders the correct index of the questions array to the DOM despite this.state.questionNumber always being one step behind in handleContinue() : import React from "react" export default class Questions extends React.Component { constructor() { super() this.state = { questionNumber: 1 } } //when Continue button is clicked handleContinue() { if (this.state

问题 I'm building a very primitive quiz app with ReactJS and I'm having trouble updating the state of my Questions component. Its behavior is it renders the correct index of the questions array to the DOM despite this.state.questionNumber always being one step behind in handleContinue() : import React from "react" export default class Questions extends React.Component { constructor() { super() this.state = { questionNumber: 1 } } //when Continue button is clicked handleContinue() { if (this.state

问题 Hmm. I'm using setState and for some reason the code following it doesn't have access to the new state! What gives?! 回答1: Yeap. It's asynchronous. I'm posting this because this isn't really immediately obvious to new React users. React "queues" updates to a component's state. If you need to execute a code block that's dependent on the new state change, pass a callback like so: getInitialState: function () { return { isFinalCountdown: false, } } //blablabla //then somewhere you got... this

问题 I've got 5 states in my app, and I use BOOL flags to mark them. But it isn't straightforward, because I have to write 5 lines to change all flags when I want to change state. Can you write some ideas or simple code to solve this problem? code: //need to choose second state flag1 = false; flag2 = true; flag3 = false; flag4 = false; flag5 = false; Also, it's to bad because I can choose 2 states one time. P.S. I found modern and more Apple-way. Answer below. 回答1: Use typedef enum to define all

问题 I've got this really strange request for an invalid URL on: Invalid URL: /cgi-bin/1st.cgi This is causing the following error: SEVERE: Exception initializing page context java.lang.IllegalStateException: Cannot create a session after the response has been committed at org.apache.catalina.connector.Request.doGetSession(Request.java:2381) at org.apache.catalina.connector.Request.getSession(Request.java:2098) at org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:833) at

问题 When I move from one view controller to another, the switch on the first controller resets itself and does not retain its state. How can I make it save its state when come back to it after viewing other controllers? And how do I make it save its state after closing the app. I have looked at the various stackOverflow questions and responses and the apple documentation, but nothing seems to work. Here is my class for the View Controller that has the switch. class Days: UIViewController {

问题 I have two exactly the same web sites hosted in two different machines under IIS 7.5. ASP.NET state service is running on my machine and the web.config is updated in both sites with the following code: <sessionState mode="StateServer" stateConnectionString="tcpip=192.168.1.77:42424" cookieless="false" timeout="120"/> The allow remote connection is set to 1 in registry in order for the second web site to access the state server. Both web sites have the same machine key: <machineKey