Adding components by constructor

Question

I have problem with adding Label by constructor, when I make it by method it's no problem

private void addLabel() {
    System.out.println("asd");
    JLabel label = new JLabel("asd");
    label.setBounds(10, 40, 100, 25);
    add(label);
    repaint();
    validate();
    System.out.println("asd2");
}

But when i try to do this same by new class and constructor i doesn't work...

Main frame:

public class Frame extends JFrame {

JButton button = new JButton("new");
AddButton button2 = new AddButton();

public Frame() {
    setLayout(null);
    setSize(400, 500);
    setDefaultCloseOperation(EXIT_ON_CLOSE);

    button.setBounds(40, 10, 50, 25);
    add(button);


    button2.setBounds(40, 40, 100, 25);
    add(button);
}

public static void main(String[] args) {
    Frame ap = new Frame();
    ap.setVisible(true);
}

AddButton class:

public class AddButton extends JPanel {
JLabel label = new JLabel("asd");

public AddButton() {
    label.setBounds(10, 40, 100, 25);
    add(label);
    repaint();
    validate();

  }

}

Ok i got it, I tried to add "button" two times istead button and button2 :D

`label.setBounds(10, 40, 100, 25);` Java GUIs have to work on different OS', screen size, screen resolution etc. As such, they are not conducive to pixel perfect layout. Instead use layout managers, or [combinations of them](http://stackoverflow.com/a/5630271/418556) along with layout padding and borders for [white space](http://stackoverflow.com/a/17874718/418556). — Andrew Thompson, Mar 05 '15 at 08:05
Please give more code for context. And what does "doesn't work" mean? Please be specific. Do you get an exception? If so, post the stack trace. Please create a [Minimal, Complete, and Verifiable example](http://stackoverflow.com/help/mcve). — dbank, Mar 05 '15 at 08:09

score 3 · Answer 1 · answered Mar 05 '15 at 08:03

3

Your constructor doesn't make sense, that's not how you should use constructors - constructors are used to create an instance of a class.

When you write

AddButton button2 = new AddButton();

then button2 is of type AddButton, and add doesn't accept this type of object.

answered Mar 05 '15 at 08:03

Maroun

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So, how to change it ? – Gumovvy Steven Mar 05 '15 at 08:05
@GumovvySteven Don't use constructor, also note that you already `add`ed the label in your constructor. – Maroun Mar 05 '15 at 08:07

score 0 · Answer 2 · answered Mar 05 '15 at 08:12

0

You can Edit like this

public class AddButton extends JPanel {
JLabel label; 

public AddButton() {
label=new JLabel("asd");
label.setBounds(10, 40, 100, 25);
add(label);
repaint();
validate();

}

}

answered Mar 05 '15 at 08:12

Anptk

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Adding components by constructor

2 Answers2