event-handling

问题 Hi so am trying to make this event change when the state is updated for some reason it's not allowing me to compile it's giving the error: The event 'Entity.StateChanged' can only appear on the left hand side of += or -= I don't know what's wrong it seems right i tried google it did not help public Entity.State state { get { return this._state; } set { if (this._state != value) { this._state = value; this.OnStateChanged(); } } } protected virtual void OnStateChanged() { if (this.StateChanged

问题 I managed to create a Candlestick Chart using JFreeChart-FX and display it using the fxgraphics2d API. But I am pretty much confused on how to enable any interaction with my chart and need some help to this. I'd be very grateful for any help in the right direction. I started with this example to get up my initial Chart and altered it so that it uses my data. Then I use a custom Canvas , which utilizes fxgraphics2d to make the JPanel component accessable as a node for my JavaFX applicaiton. So

问题 Okay, make an example here: I have UserControl A, UserControl B, UserControl C and one Windows Form. This Windows Form is only started with UserControl A. UserControl C has [Next] and [Back] buttons. Say, UserControl A is declared with an event handler. One of function in UserControl A will actually raise the event call to execute one function at UserControl C. So, at UserControl C, I have to add with "UserControlA.OneFunction += this.UserControlC_Function;" If I click Next button at

问题 Using Java, is it possible to detect user actions, such as key-presses, mouse-button-presses, and/or mouse's screen location, without the use of GUI elements? If it is, how could I implement it? Otherwise, what are the alternatives? The only StackOverflow source i found on this matter is this question, which is unanswered. And the only sources I found outside StackOverflow on this matter point to an "Invisible GUI" solution, wish is something i really want to avoid. 回答1: It can be implemented

问题 I'm trying to add & remove an event handler from a Silverlight FrameworkElement, but I just can't get the syntax correct. I want to do something like this: let clickedEventHandler = fun args -> printfn "Click!" fe.MouseLeftButtonDown.AddHandler( clickedEventHandler) ... fe.MouseLeftButtonDown.RemoveHandler(clickedEventHandler) What should be the correct way to do this? 回答1: As you already mentioned, you need to create an instance of delegate: let ch = new MouseButtonEventHandler(fun obj args

问题 I'm writing a Chrome extension that places a button next to the "reply" button of each email. And elsewhere on the page is the main React component. When the component loads, i add listeners to a custom event: componentDidMount: function() { this.listenForFileEmailEvent(); }, listenForFileEmailEvent: function() { window.addEventListener("fileThisEmail", this.handleFileEmail, false); }, I place the button in each email and setup the event: $(document).on("click", ".file-this-email", function(e

问题 I have a gwt VerticalPanel class that i need to handel KeyDown events for it. the method i used to implement keyboard handler in my class is: i add : this.sinkEvents(Event.ONKEYDOWN); to constructor then i override method onBrowserEvent() to handle key down event. @Override public void onBrowserEvent(Event event) { // TODO Auto-generated method stub super.onBrowserEvent(event); int type = DOM.eventGetType(event); switch (type) { case Event.ONKEYDOWN: //call method to handle this keydown event

问题 I am having issues with OpenLayers and unregistering the click events that are added to a layer. Basically, what I need to do is this: When a user clicks on a marker, they get a bubble that has an "edit" link in it. The user clicks that and it creates a new layer on the map and then registers a click event to the map waiting for the user to click on the map. When they click somewhere on the map, it then moves the marker to where they clicked. This all works perfectly. However, the issue is

问题 My Problem I'm writing a PowerShell script that will need to download several large files from a remote web server before carrying on with other tasks. One of my project requirements is to show the progress of each download so the end-user knows what's going on. A response to another SO question contained a solution which uses registered events and Net.WebClient.DownloadFileAsync. However, when I try the solution in the accepted answer, the download is completing long before my script has

问题 My Problem I'm writing a PowerShell script that will need to download several large files from a remote web server before carrying on with other tasks. One of my project requirements is to show the progress of each download so the end-user knows what's going on. A response to another SO question contained a solution which uses registered events and Net.WebClient.DownloadFileAsync. However, when I try the solution in the accepted answer, the download is completing long before my script has