Change the text of a JLabel - Beginner

java, jlabel, swing

Solution

It looks like you are creating two instances of `TestGU` and your `redefine` method changes the value of a label on an instance that isn't displayed.

Just checking my theory now....

Edit: You don't need to create the 2nd instance; your mainM method should be;

public void mainM() {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                frame.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

PS - I assume that your initialise method actually has this line right?

frame.getContentPane().add(la);

rather than `add(null)` as that doesn't work at all.

Problem

My code; ``` package com.test; import java.awt.EventQueue; public class TestGU { private JFrame frame; private JLabel la; /** * Launch the application. */ public void mainM() { EventQueue.invokeLater(new Runnable() { public void run() { try { TestGU window = new TestGU(); window.frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } public void redefine(String text){ la.setText(text); frame.repaint(); } /** * Create the application. */ public TestGU() { initialize(); } /** * Initialize the contents of the frame. */ private void initialize() { frame = new JFrame(); frame.setBounds(100, 100, 450, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); la = new JLabel("New label"); frame.getContentPane().add(null); } } ``` I am trying to change the Text of the Label from the main method (which is a separate class) shown below; ``` public class Test { /** * @param args */ public static void main(String[] args) { TestGU g = new TestGU(); g.mainM(); g.redefine("New Value"); } } ``` 1.) When the main method is executed, i expected the label to have the text "New Value", but it still contains the text `New label`. Nothing has changed, how can i correct this?

Original source