我很难从第一帧开始调用变量

Question

here is how should my program be. In first frame, there is a textfield1 where a user input text and when he press a button, a new frame will be display with a textfield2 that displays the inputted text from the textfield1. please help me with the syntax. i'm still a beginner in java. much thanks guys.

First Frame:

 textfield= new JTextField();
 textfield.setPreferredSize( new Dimension(200,30) ) ;
 textfield.setSize( textfield.getPreferredSize() ) ;
 textfield.setLocation(95,198) ;
 textfield.setSize(175,28);
 cont.add(textfield);


public void actionPerformed(ActionEvent e) {



        this.setVisible(false);
        new Frame2().setVisible(true); //displays the 2nd frame right?

}

now i don't know what to do on my 2nd frame or where to start because i can't get the variable from the first frame

Answer 1

You can pass the desired variables in a constructor of Frame2 :

Frame2 frame2 = new Frame2(textfield.getText());
frame2.setVisible(true);

Answer 2

All you need to do is - Define new constructor for second frame with textfield2:

public Frame2(String toDisplay){
   textfield2 = new JTextField(toDisplay);
}

Answer 3

Try this: (just copy into a new file named FrameTest.java in the default package)

import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class FrameTest extends JFrame {

  public static void main(String[] args) {
    JFrame frame = new FrameTest();
    frame.pack();
    frame.setVisible(true);
  }

  public FrameTest() {
    JPanel panel = new JPanel();

    final JTextField textField = new JTextField();
    textField.setPreferredSize(new Dimension(100, 20));
    panel.add(textField);

    JButton button = new JButton("press me");
    panel.add(button);

    setContentPane(panel);

    button.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
        FrameTest.this.setVisible(false);
        Frame2 secondFrame = new Frame2(textField.getText());
        secondFrame.pack();
        secondFrame.setVisible(true);
        }

    });
    }

    class Frame2 extends JFrame {

    public Frame2(String text) {
        getContentPane().add(new JTextField(text));
    }

    }

}