displaying labels and textfields in java swings

Question

I can't understand why in the following code only the button is being displayed , and why aren't label and textfield displayed.

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

class Invent extends JFrame
{
    public Invent(){
        JFrame c=new JFrame("trying");
        JLabel label1;
        JTextField txtfld1;
        JButton buttoncomp;  

        label1=new JLabel("Enter the path");
        txtfld1=new JTextField();
        buttoncomp=new JButton("Update");
        c.add(label1);
        c.add(txtfld1);
        c.add(buttoncomp);
        c. pack();
        c.setVisible(true);
    }

    public static void main(String[] args)
    {
        new Invent();                                                          
    }
}

Kindly help ...

Answer 1

The default layout of a JFrame's content pane is BorderLayout. You're adding all of your components to the BorderLayout.CENTER location (by calling the single-argument add() function), which means that only the last component is added.

Either use a different layout manager, or add the components to different locations in the BorderLayout.

More info about BorderLayout can be found here .

Btw, your title has nothing to do with your actual question: the difference between a JFrame and a content pane is that a JFrame contains a content pane. The JFrame class passes calls like setLayout() and add() to its content pane.

Answer 2

It works incorrect(for you but java does what you say :) )

cause you add (these)three components to JFrame in row (the next remove the last)

you must work as follows:

   label1.add(txtfld1);
   label1.add(buttoncomp);

   c.add(label1);
   c.pack();
   c.setVisible(true);

And something other...

• You had made a new JFrame you dont need to extend it(in you class).
• It's not good to add label(without panel) in HeavyWeight Component like JFrame you may have problems with Listeners(mouse,action,whatever...)

Let me know if that works for you...