Re: Ping Java Peeps
PerfectReign wrote:
http://donutmonster.com/stuff/2007/20070913_java_frames.jpg
The first frame is loaded twice.
Of course, then the button on the second frame doesn't seem to work.
Ideas??
I'll post the code inline, since the classes are not that long.
frame1.java
import javax.swing.*;
import java.awt.*;
import javax.swing.border.LineBorder;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class frame1 extends JFrame implements ActionListener{
frame2 frametwo = new frame2(this);
private static frame1 mainForm = new frame1();
In the above line you create your first instance of class frame1. You
don't need mainForm.
Remove the above line
public static void main(String args[]){
new frame1();
In the above line you create your *second* instance of class frame1.
The fact you now have two instances of frame1 should be no surprise.
}
public frame1(){
frametwo.setVisible(false);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container content = getContentPane();
content.setBackground(Color.white);
content.setLayout(new FlowLayout());
JButton button1 = new JButton("Click Me");
button1.addActionListener(this);
JLabel lblOne = new JLabel(" ");
lblOne.setBorder(new LineBorder(Color.green, 3));
content.add(lblOne);
content.add(button1);
JButton button2 = new JButton("Exit");
button2.addActionListener( this );
content.add(button2);
this.setSize(300, 300);
setVisible(true);
}
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("Exit")) {
System.exit(0);
}
if (e.getActionCommand().equals("Click Me")) {
frametwo.setVisible(true);
}
Missing:
if (e.getActionCommand().equals("Close")) {
lblOne.setText(((JTextField)getSource).getText());
}
}
Your IDE should tell you the following method is never used. I;d remove
it, its just a pointless confusing distraction to clutter your example
with unused methods.
public frame1 getMainForm() {
return mainForm;
}
}
------------------------------------------------------------
frame2.java
/*
Java test for multi-class update.
This is the second frame called from the first.
*/
import javax.swing.*;
import java.awt.*;
import javax.swing.border.LineBorder;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class frame2 extends JFrame implements ActionListener{
public class frame2 extends JFrame {
JTextField txtOne = new JTextField(20);
static ActionListener listener; // = new ActionListener();
remove that line
// static ActionListener listener; // = new ActionListener();
public static void main(String args[]){
new frame2( listener );
}
public frame2( ActionListener listener ){
setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
Container content = getContentPane();
content.setLayout(new FlowLayout());
content.add(txtOne);
JButton button2 = new JButton("Close");
//button2.addActionListener(new ButtonListener());
//button2.addActionListener(this);
button2.addActionListener(listener);
content.add(button2);
this.setSize(300, 300);
setVisible(true);
}
Remove the following method ...
/*
public void actionPerformed(ActionEvent e) {
//if (e.getActionCommand().equals("Close")) {
String blah = this.txtOne.getText();
System.out.println(blah);
// frame1.lblOne.setText(blah);
setVisible(false);
}
*/
.... up to here
/* public Form1 getFrame1(){
return this.frame1;
}
public void setFrame1(Form1 frame1){
this.frame1 = frame1;
}
*/
}
Other notes.
When posting code, just remove any commented out code. It doesn't help
us understand your current problem (I understand why you comment bits
out, I do it too, but I clean it out when posting).
Please follow usual Java conventions when writing code for posting. It
makes it easier for people like me to speed-read code if your classes
have names starting with a capital letter. "frame1" looks like an
instance name. I'd write "Frame1" instead.
Generally when comparing a String variable to a String constant it is
usually safer (from NPE) to write it the other way around:
if ("Close".equals(e.getActionCommand()))
It probably doesn't matter, but if I intend to use the results of
e.getActionCommand() more than once, I always do
String command = e.getActionCommand() and use the command variable.
It is useful to create contants to be used as ActionCommands. There is
less chance of having "Close" in one place and "close" in another.
1)
public static final String CLOSE = "Close";
....
new JButton(CLOSE);
....
if (CLOSE.equals(command)) { ...
2) Better
Use an enum
3) Best?
Use Actions
I know its a concocted example but I find variable names like lblone and
blah make comprehension more difficult. I'd invent something based on
some typical teaching example like recording names and addresses, or
students and courses, or shops and products, ...
Hope that helps