dispatch

问题 I am using React Native with Redux-thunk middleware. My problem is dispatch function does not return the object and does not even console. Here is my actions file: function movieSelc(movie) { return { type: types.MOVIE_SELECT, selectedMovie: movie }; } export function selectMovie(m) { console.log("this console works!") return (dispatch) => { console.log("this console never works") dispatch(movieSelc(m)); }; } This is the component(i am not including here const styles to make it a bit shorter)

问题 I have an object o which guaranteed at runtime to be one of three types A , B , or C , all of which implement a common interface I . I can control I , but not A , B , or C . (Thus I could use an empty marker interface, or somehow take advantage of the similarities in the types by using the interface, but I can't add new methods or change existing ones in the types.) I also have a series of methods MethodA , MethodB , and MethodC . The runtime type of o is looked up and is then used as a

问题 Suppose I have a class hierarchy in Java: interface Item { ... }; class MusicBox implements Item { ... }; class TypeWriter implements Item { ... }; class SoccerBall implements Item { ... }; and I have another class in the same package: class SpecialItemProcessor { public void add(Item item) { /* X */ } } where I want to do something different for each item type, but I don't want to define that action in the different Item classes ( MusicBox , TypeWriter , SoccerBall ). One way to handle this

问题 I'm looking for a way to add an EventListener which will automatically removes itself after the first time it fires, but I can't figure a way of doing this the way I want to. I found this function (here) : public class EventUtil { public static function addOnceEventListener(dispatcher:IEventDispatcher,eventType:String,listener:Function):void { var f:Function = function(e:Event):void { dispatcher.removeEventListener(eventType,f); listener(e); } dispatcher.addEventListener(eventType,f); } } But

问题 I need help understanding this piece of code. What is the point of handler.guid ? Why is there a need for a hash table? What is the point of: if ( element["on" + type]) { handlers[0] = element["on" + type]; } What does the "this" refer to in handleEvent , the element or the the addEvent function? function addEvent(element, type, handler) { // assign each event handler a unique ID if (!handler.$$guid) handler.$$guid = addEvent.guid++; // create a hash table of event types for the element if (

问题 Out of curiosity: how does the CLR dispatch virtual method calls to interface members to the correct implementation? I know about the VTable that the CLR maintains for each type with method slots for each method, and the fact that for each interface it has an additional list of method slots that point to the associated interface method implementations. But I don't understand the following: how does the CLR efficiently determine which interface method slot list to pick from the type's VTable?

问题 I know there are a lot of contributions already for this topic. I tried different variations with DispatchGroup, but it seems I'm not able to make the whole loop stop until a certain task is finished. let names = ["peter", "susan", "john", "peter", "susan", "john"] var holding = [String: [Double]]() for i in 0...10 { for name in names { if holding[name] == nil { Alamofire.request("https://jsonplaceholder.typicode.com", parameters: parameters).responseJSON { responseData in // do stuff here

问题 I wish to insert hooks whenever a method is called in my iOS app. So lets say there is a selector X, I wish to log "Method X starting" before the method executes, and then log "Method X ended" after the execution. I am aware of an approach where I can swizzle the implementation of sel X with the one which has the hook before and after the call to "itself", so that I can be notified when the method has executed. But, this will only work if i know the method in advance. I wish to insert hooks

问题 I have the following React view/render function: let BaseSalaryView = ({ counter, onChange }) => ( <div> <input type="text" placeholder="Annual Salary" value={counter} onChange={() => onChange(counter)} /> <span>Try: {counter}</span> </div> ) I am trying to figure out how I can pass in the value that just got changed, into my onChange dispatch handler. Attempts I have tried the following but they are all undefined. onChange={() => onChange(this.input.value)}> onChange={() => onChange(input

问题 I need to wait until Alamofire request finishes getting data. (Error or value). I'm calling Alamofire function inside a for loop in another function so that Alamofire requests should be finished before second for loop called. For example; first loop -> first request -> second loop -> second request...so on. Now It goes first loop -> second loop -> and after all loops finishes requests response is turning. Request Function: func like(sender_id: String, completion: @escaping (String?) -> ()){