Java Button Width

问题

I've tried to use this and it doesn't work

singleplayerButton.setBounds(20, 20, 200, 100);

I dont know why though, can anybody help me out with this?

My full page code is here

package gmine;

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

public class gmine implements ActionListener {
        JFrame interfaceFrame;
        JButton singleplayerButton, multiplayerButton, optionsButton, quitButton;

        public gmine() {
                JFrame.setDefaultLookAndFeelDecorated(false);
                interfaceFrame = new JFrame("G-Mine B0.4");
                interfaceFrame.setSize(800,600);
                interfaceFrame.setLayout(new GridLayout(9,1, 20, 15));

                singleplayerButton = new JButton("SinglePLayer");
                singleplayerButton.addActionListener(this);
                interfaceFrame.add(singleplayerButton);
                singleplayerButton.setBounds(20, 20, 200, 100);

                multiplayerButton = new JButton("MultiPlayer");
                multiplayerButton.addActionListener(this);
                interfaceFrame.add(multiplayerButton);

                optionsButton = new JButton("Options");
                optionsButton.addActionListener(this);
                interfaceFrame.add(optionsButton);

                quitButton = new JButton("Quit");
                quitButton.addActionListener(this);
                interfaceFrame.add(quitButton);

                interfaceFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                interfaceFrame.setVisible(true);
        }

        public void actionPerformed(ActionEvent a) {

        }

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

im trying to accomplish making the buttons smaller, so not touching the side of the page.

回答1:

I personally would use a layout manager that will give you more flexibility in deciding how the buttons are laid out and makes a great effort to honor your components preferred size, but gives you the freedom to make adjustments to as you need...

For me, that's GridBagLayout

public class ButtonsLayout {

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

    public ButtonsLayout() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new MenuPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class MenuPane extends JPanel {

        public MenuPane() {
            setLayout(new GridBagLayout());

            JButton singleplayerButton = new JButton("SinglePLayer");
            JButton multiplayerButton = new JButton("MultiPlayer");
            JButton optionsButton = new JButton("Options");
            JButton quitButton = new JButton("Quit");

            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.ipadx = 20;
            gbc.ipady = 20;

            add(singleplayerButton, gbc);
            gbc.gridy++;
            add(multiplayerButton, gbc);
            gbc.gridy++;
            add(optionsButton, gbc);
            gbc.gridy++;
            add(quitButton, gbc);
        }
    }
}

Here, I've used ipadx and ipady of the GridBagConstraints to increase the width and height of the components through the layout manager, as well as using the HORIZONTAL fill to make all the components the same width.

Have a look at

• A Visual Guide to Layout Managers
• Using Layout Managers

For more information

回答2:

• First of all when you use LayoutManager, then the position of the component and its size is controlled by the LayoutManager of the direct Parent Compoenent on when the Component is being placed..
  Eg:
  Placing a JButton on JFrame, then JFrame's LayoutManager controls the position and size of the JButton.

• I would also recommend you to use GroupLayout which was developed by NetBeans team in 2005, and you can use the WindowsBuilderPro, now free from Google.

回答3:

The GridLayout manager will give equal size to all components. You could try using a different layout manager and then use setPreferredSize(Dimension preferredSize) on your components to size them correctly.

As a different example, you could also place a JPanel on top of your JFrame and place the buttons there.

回答4:

I tried to use one of the answers above. Now the program wont show. it just terminates.

package gmine;

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

public class gmine {
        JFrame interfaceFrame;
        JButton singleplayerButton, multiplayerButton, optionsButton, quitButton;


    public void ButtonsLayout() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("G-Mine");
                interfaceFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                interfaceFrame.setLayout(new BorderLayout());
                interfaceFrame.setSize(800,600);
                interfaceFrame.add(new MenuPane());
                interfaceFrame.pack();
                interfaceFrame.setLocationRelativeTo(null);
                interfaceFrame.setVisible(true);
            }
        });
    }

    public class MenuPane extends JPanel {

        public MenuPane() {
            setLayout(new GridBagLayout());

            JButton singleplayerButton = new JButton("SinglePLayer");
            JButton multiplayerButton = new JButton("MultiPlayer");
            JButton optionsButton = new JButton("Options");
            JButton quitButton = new JButton("Quit");

            GridBagConstraints gbc = new GridBagConstraints();
            gbc.gridx = 0;
            gbc.gridy = 0;
            gbc.fill = GridBagConstraints.HORIZONTAL;
            gbc.ipadx = 20;
            gbc.ipady = 20;

            add(singleplayerButton, gbc);
            gbc.gridy++;
            add(multiplayerButton, gbc);
            gbc.gridy++;
            add(optionsButton, gbc);
            gbc.gridy++;
            add(quitButton, gbc);
        }
    }
    public static void main(String[] args) {
        new gmine();
    }

}

来源：https://stackoverflow.com/questions/13136701/java-button-width