Java GUI按钮操作已执行

Question

i'm making a simple application that can print an average of 4 numbers. And i applied Java GUI on it.

But the Nganuin! and exit button doesn't work with my code. Here's my attempt:

  private void butNganuActionPerformed(java.awt.event.ActionEvent evt) {                                         
       Double num2, num3, num4, num1, hasil;
       num1 = Double.parseDouble(l1.getText());
       num2= Double.parseDouble(l2.getText());
       num3= Double.parseDouble(l3.getText());
       num4= Double.parseDouble(l4.getText());

       hasil= (num1+num2+num3+num4)/4;

       jLabel5.setText(String.valueOf(hasil));
    }                                        

    private void exitActionPerformed(java.awt.event.ActionEvent evt) {                                     
        System.exit(0);
    }                        

What did i do wrong.

Answer 1

You probably need to replace your methods with something such as this:

butNganu.addActionListener(new ActionListener() { 
    public void actionPerformed(ActionEvent e)
    {
        Double num2, num3, num4, num1, hasil;
        num1 = Double.parseDouble(l1.getText());
        num2= Double.parseDouble(l2.getText());
        num3= Double.parseDouble(l3.getText());
        num4= Double.parseDouble(l4.getText());

        hasil= (num1+num2+num3+num4)/4;

        jLabel5.setText(String.valueOf(hasil));                                                 
    }
}); 

This will bind the button to the event handler.