.setBounds not working for JLabel and JButton

问题

I am trying to change the positioning of a JLabel and a JButton on my GUI. Even though I try to use .setBounds to change their locations; they both just appear in the top centre of the screen.

import java.awt.color.*;
import java.awt.font.*;
import java.awt.Graphics;
import java.awt.Image;
import javax.swing.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.UIManager.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class yo implements MouseListener {

Image image;
JButton button = new JButton("Wassup");
JFrame frame = new JFrame();
JLabel heloo = new JLabel("yo");
JPanel panel = new JPanel()
{
    @Override
    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        ImageIcon i = new ImageIcon("hi.jpg");
        image = i.getImage();
        g.drawImage(image,150,150,null);
        g.drawString("Hello",100,100);
        g.drawString("Hi",50,50);
    }
};


public yo()
{
    frame.add(panel);
    frame.setTitle("Hello");
    frame.setSize(500,500);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
    frame.setLocationRelativeTo(null);
    panel.add(heloo);
    panel.add(button);
    button.setBounds(200,100,200,100);
    heloo.setBounds(100,100,100,100);
    button.addMouseListener(this);
}

public void mouseClicked (MouseEvent event)
{
    heloo.setText(String.format("Clicked at %d,%d", event.getX(), event.getY()));
}
public void mouseEntered (MouseEvent Event){}
public void mouseExited (MouseEvent Event){}
public void mousePressed (MouseEvent Event){}
public void mouseReleased (MouseEvent Event){}

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

I apologise about all of the imports, I don't really know which ones I need and which ones are just pointless.

Basically I would like some help on how to change the positioning of my components.

回答1:

Don't use setBounds() to set the size and location of a component.

Let the layout manager do its job. That is if fact what is happening. A JPanel uses a FlowLayout, so the components are being positioned based on the rules of the FlowLayout. You can change the FlowLayout to align components to the left if you want. Or you can use a different layout manager.

Read the Swing tutorial on Layout Managers to find other layout managers you can use.

回答2:

public yo() {
    frame.add(panel);
    frame.setTitle("Hello");
    frame.setSize(500,500);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
    frame.setLocationRelativeTo(null);
    panel.setLayout(null);
    panel.add(heloo);
    panel.add(button);
    button.setBounds(200,100,200,100);
    heloo.setBounds(100,100,100,100);
    button.addMouseListener(this);
}

By setting the layout of the JPanel to null, it will be in the "Absolute Layout", and then you'll be able to set the position of the JLabel and JButton with setBounds().

来源：https://stackoverflow.com/questions/17264761/setbounds-not-working-for-jlabel-and-jbutton

标签

java

swing

jbutton

jlabel

layout-manager