Java, set colour of a button and not the border on a macOS?

I'm trying to assign random colors to my buttons on mouseclick. The action itself seems to work but it is not coloring my button - but the border instead! (FYI, I'm just starting to learn to code so I apologize for my '2+2=4' skills)

It also won't let me do setBorderPainted(false) within the If statements or anywhere else.

Here's my code:

import javax.swing.border.Border;
import javax.xml.transform.Source;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
public class buttonTest extends JFrame implements ActionListener {
JPanel p = new JPanel();
Random rand = new Random();
Button one, two, three, four, five, six, seven, eight, nine;
public static void main(String[] args) {
new buttonTest();
}
public buttonTest() {
super("ColourButton(2.0)");
setSize(500, 500);
setDefaultCloseOperation(EXIT_ON_CLOSE);
one = new Button("one");
two = new Button("two");
three = new Button("three");
four = new Button("four");
five = new Button("five");
six = new Button("six");
seven = new Button("seven");
eight = new Button("eight");
nine = new Button("nine");
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
Color randColor = new Color(r, g, b);
p.setLayout(new GridLayout(3, 3));
p.add(one);
p.add(two);
p.add(three);
p.add(four);
p.add(five);
p.add(six);
p.add(seven);
p.add(eight);
p.add(nine);
one.addActionListener(this);
two.addActionListener(this);
three.addActionListener(this);
four.addActionListener(this);
five.addActionListener(this);
six.addActionListener(this);
seven.addActionListener(this);
eight.addActionListener(this);
nine.addActionListener(this);
add(p);
setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e) {
String clickedbutton = e.getActionCommand();
System.out.println(clickedbutton + " button clicked.");
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
Color randColor = new Color(r, g, b);
if (e.getSource() == one) {
one.setBackground(new Color(r,g,b));
} else if (e.getSource() == two) {
two.setBackground(new Color(r,g,b));
} else if (e.getSource() == three) {
three.setBackground(new Color(r,g,b));
} else if (e.getSource() == four) {
four.setBackground(new Color(r,g,b));
} else if (e.getSource() == five) {
five.setBackground(new Color(r,g,b));
} else if (e.getSource() == six) {
six.setBackground(new Color(r,g,b));
} else if (e.getSource() == seven) {
seven.setBackground(new Color(r,g,b));
} else if (e.getSource() == eight) {
eight.setBackground(new Color(r,g,b));
} else {
nine.setBackground(new Color(r,g,b));
}
}
}
</details>
# 答案1
**得分**: 1
```java
// "long" answer would involve creating your own UI delegate class which allowed you to take full control over the buttons appearance, but that seems like a lot of effort for something so simple.
// A place to start is looking at `setBorderPainted` and `setContentAreaFilled`.  This will allow you to, generally, remove all the customisation done by the platforms UI delegate, but in my testing, I also need to use `setOpaque(true)`
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
frame.add(new ButtonTest());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ButtonTest extends JPanel implements ActionListener {
Random rand = new Random();
JButton buttons[];
public ButtonTest() {
buttons = new JButton[9];
setLayout(new GridLayout(3, 3));
for (int i = 0; i < buttons.length; i++) {
buttons[i] = new JButton(Integer.toString(i));
buttons[i].setBorderPainted(false);
// This may not be needed, but shouldn't hurt
buttons[i].setContentAreaFilled(false);
// This is what fixed the issue for me
// But you might need to consider providing a "default"
// background color OR change this in the `actionPerformed`
// method
buttons[i].setOpaque(true);
buttons[i].addActionListener(this);
add(buttons[i]);
}
}
@Override
public void actionPerformed(ActionEvent e) {
if (!(e.getSource() instanceof JButton)) {
return;
}
String clickedbutton = e.getActionCommand();
System.out.println("You clicked " + clickedbutton);
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
JButton button = (JButton) e.getSource();
button.setBackground(new Color(r, g, b));
}
}
}

import java.awt.Color;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame();
frame.add(new ButtonTest());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ButtonTest extends JPanel implements ActionListener {
Random rand = new Random();
JButton buttons[];
public ButtonTest() {
buttons = new JButton[9];
setLayout(new GridLayout(3, 3));
for (int i = 0; i < buttons.length; i++) {
buttons[i] = new JButton(Integer.toString(i));
buttons[i].setBorderPainted(false);
// This may not be needed, but shouldn't hurt
buttons[i].setContentAreaFilled(false);
// This is what fixed the issue for me
// But you might need to consider providing a "default"
// background color OR change this in the `actionPerformed`
// method
buttons[i].setOpaque(true);
buttons[i].addActionListener(this);
add(buttons[i]);
}
}
@Override
public void actionPerformed(ActionEvent e) {
if (!(e.getSource() instanceof JButton)) {
return;
}
String clickedbutton = e.getActionCommand();
System.out.println("You clicked " + clickedbutton);
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
JButton button = (JButton) e.getSource();
button.setBackground(new Color(r, g, b));
}
}
}

答案2

得分: 0

使用 button.setBorderPainted(false); 对所有的 JButtons 进行设置，这将去除边框。但如果这不是你所讨论的内容，那么我不明白你试图做什么；你的 JButtons 在被点击时会改变颜色，而不是边框。

此外，为了减少你的代码量，我强烈建议创建一个 JButton 数组，其中包含了所有的 JButtons，这样你就不需要为每个单独的 JButton 编写初始化和设置颜色的代码。

下面是我修改后的代码：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.*;

public class ButtonTest extends JFrame implements ActionListener {

    JPanel p = new JPanel();
    Random rand = new Random();
    JButton buttons[];

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

    public ButtonTest() {
        super("ColourButton(2.0)");
        setSize(500, 500);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        buttons = new JButton[9];
        p.setLayout(new GridLayout(3, 3));
        for (int i = 0; i < buttons.length; i++) {
            buttons[i] = new JButton(Integer.toString(i));
            buttons[i].setBorderPainted(false);
            buttons[i].addActionListener(this);
            p.add(buttons[i]);
        }

        add(p);
        setVisible(true);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String clickedButton = e.getActionCommand();
        System.out.println(clickedButton + " button clicked.");

        float r = rand.nextFloat();
        float g = rand.nextFloat();
        float b = rand.nextFloat();

        JButton button = (JButton) e.getSource();

        button.setBackground(new Color(r, g, b));
        button.setForeground(new Color(0, 0, 0, 250));
    }
}

 import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.*;
public class ButtonTest extends JFrame implements ActionListener {
JPanel p = new JPanel();
Random rand = new Random();
JButton buttons[];
public static void main(String[] args) {
new ButtonTest();
}
public ButtonTest() {
super("ColourButton(2.0)");
setSize(500, 500);
setDefaultCloseOperation(EXIT_ON_CLOSE);
buttons = new JButton[9];
p.setLayout(new GridLayout(3, 3));
for (int i = 0; i < buttons.length; i++)
{
buttons[i] = new JButton(Integer.toString(i));
buttons[i].setBorderPainted(false);
buttons[i].addActionListener(this);
p.add(buttons[i]);
}
add(p);
setVisible(true);
}
@Override
public void actionPerformed(ActionEvent e) {
String clickedbutton = e.getActionCommand();
System.out.println(clickedbutton + " button clicked.");
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
JButton button = (JButton)e.getSource();
button.setBackground(new Color(r,g,b));
button.setForeground(new Color(0, 0, 0, 250));
}
}