What is actionPerformed method in Java?
The method actionPerformed handles all the actions of a component, and inside this method, you will define or write your own codes that will be executed when an action occurred. Here’s an example on how to implement ActionListener in Java.
How do you call an actionPerformed method in Java?
Using actionPerformed from Another Java Class
- Step 1: Create an event handler class and specify that the class either implements an ActionListener interface or extends a class that implements an ActionListener interface.
- Step 2: Register an instance of the event handler class as a listener on one or more components.
What is actionPerformed ActionEvent E in Java?
The actionPerformed() method is invoked automatically whenever you click on the registered component. public abstract void actionPerformed(ActionEvent e);
What is e getSource method in Java?
Description. object getSource() Returns the object on which the event occurred. You can use the getSource method to determine which component sourced the event when the listener is registered as an event listener with more than one component.
What does actionPerformed do?
addActionListener(instanceOfMyClass); Include code that implements the methods in listener interface. For example: public void actionPerformed(ActionEvent e) { …//code that reacts to the action… }…The Action Listener API.
| Method | Purpose |
|---|---|
| actionPerformed(actionEvent) | Called just after the user performs an action. |
What is the use of ActionEvent class?
Class ActionEvent. A semantic event which indicates that a component-defined action occurred. This high-level event is generated by a component (such as a Button ) when the component-specific action occurs (such as being pressed).
What is the difference between getSource and getActionCommand?
The getActionCommand() method returns an String associated with that Component set through the setActionCommand() , whereas the getSource() method returns an Object of the Object class specifying the source of the event.
Why is getSource () Used with JButton in event handling?
The getSource() method returns a reference to the source of the event that triggered the call to actionPerformed. The conditional will be true if the source object is an instance of JButton, i.e., if the source object is an object from the JButton class (or a subclass of JButton).
What is an ActionEvent Java?
public class ActionEvent extends AWTEvent. A semantic event which indicates that a component-defined action occurred. This high-level event is generated by a component (such as a Button ) when the component-specific action occurs (such as being pressed).
What is the purpose of action interface in Swing?
In addition to the actionPerformed method defined by the ActionListener interface, this interface allows the application to define, in a single place: One or more text strings that describe the function. These strings can be used, for example, to display the flyover text for a button or to set the text in a menu item.
What is an ActionEvent in Java?