event-handling

问题 I am having a problem with the handling of an index changed event for a comboBox that resides inside a dataGridView. I write an method to handle the comboBox selection change using either a delegate: ComboBox.SelectedIndexChanged -= delegate { ComboBoxIndexChanged(); }; ComboBox.SelectedIndexChanged += delegate { ComboBoxIndexChanged(); }; or an EventHandler: comboBox.SelectedIndexChanged += new EventHandler(ComboBoxIndexChanged); but both methods do not work as expected. That is, when you

问题 I want to handle MouseEnter event for a Custom Control when control is disabled. Is there a way to handle it? 回答1: The documentation for UIElement.IsEnabled documents the behaviour you see: Elements that are not enabled do not participate in hit testing or focus and therefore will not be sources of input events. The logical conclusion, to me, is that if you do want to handle mouse events, you don't disable the control. Instead, use some other method of achieving what you want. For example, if

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 7 years ago . I searched on Google to learn how to create custom events and event listeners. After reading some articles about it, I'm still confused. I would like to ask you guys for a review of the ways for making custom

问题 There is a textarea element which converts itself into a div when onblur event happens on that same textarea . There is also a button which has its onclick property set to function f . If one is writing in the textarea and then clicks on a button , f is fired, but also onblur event handler is triggered. Is there some order rules in this case, or the two handler functions may fire in random order? 回答1: I created a jsfiddle here: http://jsfiddle.net/z5SEp/ The events for latest Chrome seem to

问题 this code that adds registers new EventHandler(s) for an event named as NewMail (the eventargs class is named NewMailEventArgs . // A PUBLIC add_xxx method (xxx is the event name) // Allows methods to register interest in the event. public void add_NewMail(EventHandler<NewMailEventArgs> value) { // The loop and the call to CompareExchange is all just a fancy way // of adding a delegate to the event in a thread-safe way. EventHandler<NewMailEventArgs> prevHandler; EventHandler<NewMailEventArgs

问题 So I followed the guide on the following site to restrict the characters a textbox can accept. http://www.rhyous.com/2010/06/18/how-to-limit-or-prevent-characters-in-a-textbox-in-csharp/ My problem is I can't figure out how to make the event handler trigger in the secondary class. Basically how do I tell VS to look for the event handler code in that class instead of MainWindow? I tried searching, but apparently don't know the correct terms to use. The xaml reference I used was xmlns:DigitBox=

问题 I'm looking for a way to detect when a checkbox checked value has been changed. addEventListener() or jQuery on() mostly work, but neither will detect a change made this way: <input type="checkbox" id="testCheckbox"> <!--- some other script further down the page, not under my control --> <script type="text/javascript"> document.getElementById("testCheckbox").checked = true; </script> Is there a way I can detect this change ? Even something that only works in the latest browsers would be great

问题 Is there any way to handle key press events in ApplicationWindow of QtQuick.Controls component? Documentation of Qt5.3 does not provide any way to do this. Also, it says that Keys is only exists in Item -objects . When I try to handle key press event it says " Could not attach Keys property to: ApplicationWindow_QMLTYPE_16(0x31ab890) is not an Item ": import QtQuick 2.2 import QtQuick.Controls 1.2 import QtQuick.Controls.Styles 1.1 import QtQuick.Window 2.1 ApplicationWindow { id: mainWindow

问题 I realise there are other questions on preventDefault() not working with Firefox, but they did not help me. I've got three SELECT lists, and all I want is to navigate between them using the arrow keys without changing any values . The code works great in Chrome, but in Firefox it moves focus and then changes the value on the element just moved to. http://jsbin.com/ofitif/3/edit JavaScript: $(document).ready(function () { $('.myinput').keydown(function (evt) { onkeydown(evt); }); $('.myinput

问题 What is a reliable way to detect change of a select slider in jQuery Mobile? I try to bind a handler to change event of the select control itself, but it fires on initial page display, and then fires multiple times on clicks, and sometimes even on hover (in desktop browser). The minimal working example of this behaviour is posted here: http://jsfiddle.net/NPC42/mTjtt/3/ This is probably caused by jQuery Mobile adding more elements to style the select as the flip-toggle, but I can't find the