Help me ..how I can add an action to the button

[NoOor nice]

Hello everybody

I have problem in adding an action to the buttons from separate class..
I know how to add the actionListner class as inner class but if I want to ceate this class separate from other classes..how I can implement it..
it show me many errors..
this is the class I wrote...I don't know what the wrong

import javax.swing.*;
import java.awt.*;

public class PersonInfoForm {

JFrame frame;
JTextField nameTF;
JTextField lastNameTF;
JButton clearB, printB;


public PersonInfoForm() {

frame = new JFrame("Person Information");
frame.setSize(300, 300);
Container mainC = frame.getContentPane();
mainC.setLayout(new GridLayout(3, 2));


mainC.add(getNamePanel());
mainC.add(getLastNamePanel());
mainC.add(getCommandPanel());

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void showForm () {
frame.setVisible(true);
}

protected JPanel getNamePanel() {
JPanel nameP = new JPanel();
nameP.setLayout(new FlowLayout(FlowLayout.LEFT));
JLabel nameL = new JLabel("Name: ");
nameTF = new JTextField(10);
nameP.add(nameL);
nameP.add(nameTF);
return nameP;

}

protected JPanel getLastNamePanel(){
JPanel lastNameP = new JPanel();
lastNameP.setLayout(new FlowLayout(FlowLayout.LEFT));
JLabel lastNameL = new JLabel("Last Name: ");
lastNameTF = new JTextField(10);
lastNameP.add(lastNameL);
lastNameP.add(lastNameTF);
return lastNameP;
}

protected JPanel getCommandPanel(){

JPanel commandP = new JPanel();
commandP.setLayout(new FlowLayout(FlowLayout.LEFT));
clearB = new JButton("Clear");
printB = new JButton("Display Info");
commandP.add(clearB);
commandP.add(printB);
// clearB.addActionListener(new displayAction());
printB.addActionListener(new displayAction());
return commandP;
}
public JTextField nameTF(){
return nameTF;
}

/* class displayAction implements ActionListener{
public void actionPerformed(ActionEvent e){
String messg = nameTF.getText()+ ", "+lastNameTF.getText();
JOptionPane.showMessageDialog(null,messg);
}
}*/

}
as u see I add the ActionListner class as inner class and it work but when I try to use it in separate class the program not working
this is the class of action

import java.awt.event.*;
import javax.swing.*;

class displayAction implements ActionListener {
PersonInfoForm info;
public void actionPerformed(ActionEvent e) {

String messg = info.nameTF().getText() + ", " + info.lastNameTF.getText();
JOptionPane.showMessageDialog(null, messg);
}
}
I try to use an object for the PersonInfoForm but it still give me an error
and this is my test class

public class Test {

public static void main(String[] args) {

PersonInfoForm info = new PersonInfoForm();
info.showForm();
}

}


plz...help me ^_^

NoOor

[Eddie Vanda]

// [quote]Originally posted by NoOor nice:
//Hello everybody
 
//I have problem in adding an action to the buttons from separate class..
//I know how to add the actionListner class as inner class but if I want to ceate this class separate from other classes..how I can implement it..
//it show me many errors..
//this is the class I wrote...I don't know what the wrong
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
class PersonInfoForm {
 
  JFrame frame;
  JTextField nameTF;
  JTextField lastNameTF;
  JButton clearB, printB;
 

  PersonInfoForm() {
 
    frame = new JFrame("Person Information");
    frame.setSize(300, 300);
    Container mainC = frame.getContentPane();
    mainC.setLayout(new GridLayout(3, 2));
 

    mainC.add(getNamePanel());
    mainC.add(getLastNamePanel());
    mainC.add(getCommandPanel());
 
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      }
 
  public void showForm () {
    frame.setVisible(true);
  }
 
  protected JPanel getNamePanel() {
    JPanel nameP = new JPanel();
    nameP.setLayout(new FlowLayout(FlowLayout.LEFT));
    JLabel nameL = new JLabel("Name: ");
    nameTF = new JTextField(10);
    nameP.add(nameL);
    nameP.add(nameTF);
    return nameP;
 
  }
 
  protected JPanel getLastNamePanel(){
    JPanel lastNameP = new JPanel();
      lastNameP.setLayout(new FlowLayout(FlowLayout.LEFT));
      JLabel lastNameL = new JLabel("Last Name: ");
      lastNameTF = new JTextField(10);
      lastNameP.add(lastNameL);
      lastNameP.add(lastNameTF);
      return lastNameP;
  }
 
  protected JPanel getCommandPanel(){
 
    JPanel commandP = new JPanel();
   commandP.setLayout(new FlowLayout(FlowLayout.LEFT));
   clearB = new JButton("Clear");
   printB = new JButton("Display Info");
   commandP.add(clearB);
   commandP.add(printB);
 //  clearB.addActionListener(new displayAction());
   printB.addActionListener(new displayAction(this));
return commandP;
  }
  public JTextField nameTF(){
  return nameTF;
  }
 
/*  class displayAction implements ActionListener{
    public void actionPerformed(ActionEvent e){
String messg = nameTF.getText()+ ", "+lastNameTF.getText();
       JOptionPane.showMessageDialog(null,messg);
    }
  }*/
 
}
//as u see I add the ActionListner class as inner class and it work but when I try to use it in separate class the program not working
//this is the class of action
 
class displayAction  implements ActionListener {
  PersonInfoForm info;
 

   displayAction (PersonInfoForm pif) {
     info = pif;
   }
     public void actionPerformed(ActionEvent e) {
 
      String messg = info.nameTF().getText() + ", " + info.lastNameTF.getText();
      JOptionPane.showMessageDialog(null, messg);
    }
  }
//I try to use an object for the PersonInfoForm but  it still give me an error
//and this is my test class
 
public class TestActionClass {
 
  public static void main(String[] args) {
 
    PersonInfoForm info = new PersonInfoForm();
    info.showForm();
  }
 
}
 

//plz...help me ^_^
 
//NoOor[/quote]
 

Hi NoOor

I ran your code and got a null pointer exception in your action class because you had not initialized variable "info". I removed a couple of public statements, renamed the class with "main" to "TestActionClass", and added the constructor to the action class to set a value into "info". It now runs fine!

Ed

[NoOor nice]

Hi Eddie Vanda

thank u ,, I try the program and it work now ...really thanx a lot ^_^