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I'm new to java and I wanted to create an app that opens a window and has two buttons that say differnt things. But there seems to be a problem and I do not know how to fix it.
Thanks for your help in advance.
package fenster;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Fenster {
public static void main(String[] args) {
JFrame myFrame=new JFrame ("This is my window.");
myFrame.setSize(300,400);
myFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
myFrame.setVisible(true);
JPanel panel= new JPanel();
myFrame.add(panel);
JButton button= new JButton("Hello World!");
panel.add(button);
button.addActionListener(new Action1()); // there's an error here
JButton button2= new JButton("Hello again!");
panel.add(button2);
button2.addActionListener (new Action2()); // there's an error here
}
}
package fenster;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Fenster {
public static void main(String[] args) {
JFrame myFrame=new JFrame ("This is my window.");
myFrame.setSize(300,400);
myFrame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
myFrame.setVisible(true);
}
public Fenster(){
JPanel panel= new JPanel();
myFrame.add(panel);
JButton button= new JButton("Hello World!");
panel.add(button);
button.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent evt)
{
//code here
}
}
JButton button2= new JButton("Hello again!");
panel.add(button2);
button2.addActionListener (new ActionListener(){
public void actionPerformed(ActionEvent evt)
{
//code here
}
}
}
}
First don't add all your code under the main method its better to create a constructor or other methods instead of the main.
Second the reason you got an error because new action2, here you have to create a class called Action2 and class called Action1 . Both these classes should implement ActionListener.
Or
You can create an anonymous listener like the one that I did new ActionListener that way you dont have to create a class every time.
Check this for more info:
ActionListener
Related
Here is my code, but the error shows that the implemented ActionListener is not correct. I also declared the buttons so how do I make the system exit? What did I do wrong? Thanks in advance
import javax.swing.*;
import java.awt.*;
import java.awt.FlowLayout;
public class MyFrame extends JFrame implements ActionListener {
public MyFrame() {
// set flow layout for the frame
this.getContentPane().setLayout(new FlowLayout());
JButton ExitBtn = new JButton();
ExitBtn.setText("Exit");
JButton Find = new JButton("Find");
JButton Clear = new JButton("Clear");
// add buttons to frame
add(ExitBtn);
add(Find);
add(Clear);
}
public void actionPerformed(ActionEvent e){
System.exit(0);
ExitBtn.addActionListener(this);
}
public static void main(String[] args) {
MyFrame mf = new MyFrame();
mf.pack();
mf.setVisible(true);
mf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
onClick:
frame.dispatchEvent(new WindowEvent(frame, WindowEvent.WINDOW_CLOSING));
I think you should move the ExitBtn.addActionListener(this) call to the constructor of MyFrame class so that it looks like this:
JButton ExitBtn = new JButton();
ExitBtn.setText("Exit");
ExitBtn.addActionListener(this)
and actionPermormed method looks like this:
#Override
public void actionPerformed(ActionEvent e){
System.exit(0);
}
Hi take a look on this code:
package arkanoid;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.Color;
import java.awt.event.*;
public class Arkanoid extends JFrame
{
private static final long serialVersionUID = 6253310598075887445L;
static JFrame frame;
static class Action1 implements ActionListener {
public void actionPerformed (ActionEvent e) {
//frame = new JFrame("Arkanoid");
frame.setLocationRelativeTo(null);
frame.setIgnoreRepaint(true);
frame.setResizable(false);
frame.setVisible(true);
frame.setSize(500,400);
frame.add(new Gra());
}
}
static class Action2 implements ActionListener {
public void actionPerformed (ActionEvent e) {
frame.dispose();
System.exit(0);
}
}
public static void main(String[] args)
{
//new Arkanoid();
frame = new JFrame("Arkanoid");
frame.setSize(500,400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Arkanoid BETA");
frame.setLocationRelativeTo(null);
frame.setIgnoreRepaint(true);
frame.setResizable(false);
frame.setVisible(true);
JPanel panel = new JPanel();
frame.add(panel);
JButton button = new JButton("Nowa Gra");
panel.add(button);
button.addActionListener (new Action1());
JButton button2 = new JButton("Wyjscie");
panel.add(button2);
button2.addActionListener (new Action2());
}
}
This code almost works, I want to make a button2 a quit button working like X button in top right frame's icons and button1 need to open a Gra() in the same window. When im doing it like this it isnt work fine:/ i need to click 2 times on button1 to go to Gra() and what is more KeyListeners in Gra() arent working :(
Im new in buttons, frames and panels in java so please help with this code. Correct it please.
There are a number of fundamental problems with your code, the least of which is why your button1 requires 2 clicks.
However, for your problem you should try rearranging the order of your button1 listener, so that your Component is added to the frame first, before setting it to be visible. An example that should work:
static class Action1 implements ActionListener {
public void actionPerformed (ActionEvent e) {
frame.add(new Gra());
frame.revalidate();
}
}
Note you have already set the size, location etc of frame in main, so there is no need to set them again every time the button is clicked.
I stress that there are more important problems with your code than this issue. You should take a look at Java's Modifier Types (static does not seem applicable here), as well as object-oriented concepts such as inheritance (you define your Arkanoid class to extend JFrame, yet have a JFrame object as a class variable).
I want to make a button2 a quit button working like X button in top right frame's
You can use the ExitAction class found in Closing an Application.
For other examples of how to use buttons read the Swing tutorial on How to Use Buttons. This is the place to start for all you Swing related questions.
There are many problems with your code. I've refactored it a little. With below code & #ricky116 answer I think you should get all of them.
import javax.swing.*;
import java.awt.Color;
import java.awt.event.*;
public class Arkanoid extends JFrame
{
public Arkanoid() {
super("Arkanoid");
setSize(500,400);
setTitle("Arkanoid BETA");
setLocationRelativeTo(null);
setResizable(false);
final JPanel panel = new JPanel();
setContentPane(panel);
panel.add(new JButton(new AbstractAction("Nowa Gra") {
public void actionPerformed (ActionEvent e) {
panel.removeAll();
panel.add(new Gra());
panel.revalidate();
panel.repaint();
}
});
panel.add(new JButton(new AbstractAction("Wyjscie") {
public void actionPerformed (ActionEvent e) {
Arkanoid.this.setVisible(false);
}
});
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Arkanoid frame = new Arkanoid();
frame.setVisible(true);
}
});
}
}
This question already has an answer here:
Closed 10 years ago.
Possible Duplicate:
JButton minimizing a window(JFrame)
I removed the JFrame's close/minimize buttons, and I want to add my own buttons, for close, it can work by using .dispose();, but what should I use to minimize the JFrame if I click on a JButton?
I think .setVisible(false); will hide it completely, and I won't have anything to click on, in the TaskBar to get the JFrame back.
Just use .setState(Frame.ICONIFIED)
Working Example:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class FrameTest {
public static void main(String args[]) throws Exception {
final JFrame frame = new JFrame();
frame.setUndecorated(true);
JButton button = new JButton("Minimize");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
frame.setState(Frame.ICONIFIED);
}
});
frame.add(button);
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}
}
Try this:
frame.setExtendedState(frame.getExtendedState | Frame.ICONIFIED);
or
frame.setExtendedState(frame.getExtendedState | ~Frame.MAXIMIZED_BOTH);
Ok, i started learning java, and this is a code from internet that doesn't work on my pc
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class form2
{
public static void main(String args[])
{
// Create Frame 1
JFrame frame = new JFrame("Frame 1");
frame.setSize(333,333);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create panel
JPanel panel = new JPanel();
// Create button
JButton button = new JButton("Press me!");
// Add things
panel.add(button);
frame.add(panel);
frame.setVisible(true);
// Add the action listener to that button
button.addActionListener(new action());
static class action implements ActionListener
{
public void actionPerformed (ActionEvent e)
{
// Create Frame 2
JFrame frame2 = new JFrame("Frame 2");
frame2.setSize(200,200);
frame2.setVisible(true);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel label = new JLabel("Clicked!");
JPanel panel2 = new JPanel();
// First add to frame2 the panel just create
frame2.add(panel2);
// Add to panel the label
panel2.add(label);
}
}
}
}
And it give me an error about action and i don't understand why.
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
action cannot be resolved to a type
Illegal modifier for the local class action; only abstract or final is permitted
at form2.main(form2.java:26)
What is my problem?? On that guy's computer works
http://www.youtube.com/watch?v=jEXxaPQ_fQo&feature=channel_video_title
Can anyone help me??
You are declaring a static class inside of a method which you shouldn't do. So take it out of the method, or better, make it an anonymous inner class:
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// Create Frame 2
JFrame frame2 = new JFrame("Frame 2");
frame2.setSize(200, 200);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel label = new JLabel("Clicked!");
JPanel panel2 = new JPanel();
// First add to frame2 the panel just create
frame2.add(panel2);
// Add to panel the label
panel2.add(label);
frame2.setVisible(true);
}
});
What does this question have to do with java-ee by the way??
You declare a class inside a method, in this case main, however, it should be outside of it, like the guy in the video says.
Hope that helps!
Static classes cannot be defined inside a method. Move the class definition static class .... { } outside of your main method. Also, it is good practice to start classes with an uppercase character (e.g AddPanelAction).
The actionlistener class must be declared outside of the main method like this:
import javax.swing.*;
import java.awt.event.*;
public class Main
{
public static void main(String args[])
{
// Create Frame 1
JFrame frame = new JFrame("Frame 1");
frame.setSize(333,333);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Create panel
JPanel panel = new JPanel();
// Create button
JButton button = new JButton("Press me!");
// Add things
panel.add(button);
frame.add(panel);
frame.setVisible(true);
// Add the action listener to that button
button.addActionListener(new action());
}
public static class action implements ActionListener {
public void actionPerformed(ActionEvent e) {
// Create Frame 2
JFrame frame2 = new JFrame("Frame 2");
frame2.setSize(200,200);
frame2.setVisible(true);
frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel label = new JLabel("Clicked!");
JPanel panel2 = new JPanel();
// First add to frame2 the panel just create
frame2.add(panel2);
// Add to panel the label
panel2.add(label);
}
}
}
Or you can declare the actionlistener by using an anonymous inner class like this:
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// Do things here
}
});
Static classes can not be defined inside a method. Move that class outside the main method or declare your class non-static within the main method itself, if you need . A static class always requires one outer non-static class.
A day late and dollar short.... but I'll still add it.
Most of the Java actionListener examples on the web are too darn complex. To understand it, you just really need a form, button, and the actionListener. In the example below, the form server as the listener through the addition of 'implements ActionListener'.
import java.applet.Applet;
import java.awt.Button;
import java.awt.Toolkit;
import java.awt.BorderLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class Sample extends Applet implements ActionListener {
Button button;
public void init() {
setLayout(new BorderLayout());
button = new Button("Test");
add("Center", button);
button.addActionListener(this);
}
public void actionPerformed(ActionEvent e) {
// your code to do what you want when the button was clicked goes here
}
}
i am trying to make an actionListener on a button in another button which has also an actionlistener and i just couldn't figure it out for some way. I am trying to make an action on the 2nd button but i couldn't figure it out.If anyone helps me i'd appreciate! here is the code below:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.util.*;
public class basic implements ActionListener{
public static void main(String[] args) {
basic process = new basic ();
}
public basic(){
JFrame fan = new JFrame("Scheme");
JPanel one = new JPanel(new BorderLayout());
fan.add(one);
JPanel uno = new JPanel();
uno.setLayout(new BoxLayout(uno, BoxLayout.Y_AXIS));
JButton addB = new JButton("first choice");
addB.setAlignmentX(Component.CENTER_ALIGNMENT);
uno.add(addB);
addDButton.setActionCommand("hehe");
addDButton.addActionListener(this);
one.add(uno,BorderLayout.CENTER);
fan.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fan.setSize(500,700);
fan.setLocationByPlatform(true);
fan.setVisible(true);
}
public void actionPerformed(ActionEvent evt) {
JPanel markP = new JPanel(new FlowLayout(FlowLayout.RIGHT,10,20));
JDialog dialog = new JDialog((JFrame)null);
dialog.getContentPane().add(markP,BorderLayout.CENTER);
if (evt.getActionCommand().equals("hehe")) {
JLabel title = new JLabel("Proceed");
title.setFont(new Font("Arial",Font.BOLD,15));
markP.add(title,BorderLayout.NORTH);
JButton exit = new JButton("Exit");
markP.add(exit);
//here i want to create another actionListener on the exit button only without affecting the other content which is in the button "addB " so that when i click on the addB button the J dialog pops up, and than when i click on exit button the program will return to the menu.I couldn't figure it out.
dialog.toFront();
dialog.setModal(true);
dialog.pack(); //
dialog.setLocationRelativeTo(null); //
dialog.setVisible(true);
}
// here the code goes on but the problem is that of the actionListener which is concerned.
JButton exit = new JButton("Exit");
exit.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
// you code here
}
});
You should use better variables names. It is not easy to follow your code
You could use the same ActionListener if you check the source of the action using
if (evt.getSource().equals(addDButton) { original code }
else { code for the other button }