event-handling

问题 Current Situation: I have a parent and a child component. The parent initializes the child 's data using its @Input . And the child notifies the parent, when the user edited the data using the @Output . And because the data is immutable , the child has to send the data along with that notification. When the parent got notified, it will check if the submitted data is valid, and then will set it (this will propagate the new value to some other child components as well). The Problem: When

问题 I am writing a WPF application that has two windows. I have a MainWindowViewModel that holds two more view models: AllTagsViewModel and PlotViewModel . public AllTagsViewModel AllTagsViewModel { get; private set; } public PlotViewModel PlotViewModel { get; private set; } At the moment, I'm using this solution as a click handler in the main window: private void LaunchPlotWindow_OnClick(object sender, RoutedEventArgs e) { if (PlotWindow.GlobalInstanceCount == 0) { PlotWindow plotWindow = new

问题 After the last library update (my jar files dates is 22. Oct.) The event handling does not work as expected. For example the SwipeEvent in SwipeableContainer and the ActionListener in FloatinAutton works. But the button and MultiButton does not. I debuged it. Does not fall into any EventDispatcher instance that includes relevant listener. So the handler code defined in the form (multiButton.addActionListener(e -> {...) is not called anymore. This phenomenon can be reproduced by recompiling

问题 Here I added a model to my viewmodel... public dal.UserAccount User { get { return _user; } set { _user = value; RaisePropertyChanged(String.Empty); } } I handle property change event... public event PropertyChangedEventHandler PropertyChanged; private void RaisePropertyChanged(string propertyName) { if (this.PropertyChanged != null) this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } This is the binding i use. <TextBox Text="{Binding User.firstname, Mode=TwoWay,

问题 I've written two event handlers for the TextBox.Leave event for a TextBox1 The reason for this is that the first handler is a common one for multiple TextBox.Leave events which validates the values, and the second one is specific for the above TextBox1 which does some calculation of values. My query is that can I know which of the two handlers will execute first when TextBox1.Leave happens? (I know I can remove the code from the common handler to the specific one for TextBox1 , but still I

问题 I've written two event handlers for the TextBox.Leave event for a TextBox1 The reason for this is that the first handler is a common one for multiple TextBox.Leave events which validates the values, and the second one is specific for the above TextBox1 which does some calculation of values. My query is that can I know which of the two handlers will execute first when TextBox1.Leave happens? (I know I can remove the code from the common handler to the specific one for TextBox1 , but still I

问题 I can't figure out how to trigger a keydown event on a textarea element, e.g. imagine i have two textarea elements and when i type something in the first one, I want the second box to show the typing as well, but for a certain reason I have to do it via events. This is what I tried and it doesn't work: <script language="javascript" type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.js"></script> <textarea id='first'></textarea> <textarea id='second'><

问题 I've been trying to learn about events/delegates, but am confused about the relationship between the two. I know that delegates allow you to invoke different functions without needing to know what particular function is being invoked. (eg: a graphing function needs to accept inputs that are different functions to be graphed). But I don't see how delegates are used in Events. Can someone construct a simple example (in pseudocode or C# or Java) that illustrates the workings of Delegates as

问题 This question already has answers here : Javascript “addEventListener” Event Fires on Page Load [duplicate] (2 answers) Closed 2 years ago . I was experimenting [in jsfiddle] w/a function created to append a newly created TextNode to the <p> in the HTML below: <button onclick="addTextNode('YES! ');">YES!</button> <button onclick="addTextNode('NO! ');">NO!</button> <button onclick="addTextNode('WE CAN! ');">WE CAN!</button> <hr /> <p id="p1">First line of paragraph.</p> Here is my javascript

问题 I have the following class, which has one public event called LengthChanged : class Dimension { public int Length { get { return this.length; } set { if (this.length != value) { this.length = value; this.OnLengthChanged (); } } protected virtual void OnLengthChanged() { var handler = this.LengthChanged; if (handler != null) { handler (this, System.EventArgs.Empty); } } public event System.EventHandler LengthChanged; private int length; } I would like to be able to register/unregister handlers