我创建了 3 个按钮。它们各自在 JFrame 中显示两次。我在更改框架背景时遇到问题。我已经设置了 ActionListeners 但单击后没有任何变化。我可以寻求帮助吗?
public class MyButtons extends JPanel {
public static JFrame frame;
private JButton Red = new JButton("Red");
private JButton Green = new JButton("Green");
private JButton Blue = new JButton("Blue");
public void InitializeButton()
{
Blue.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.BLUE);
}
});
Green.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.GREEN);
}
});
Red.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
frame.setBackground(Color.RED);
}
});
}
public MyButtons() {
InitializeButton();
add(Red);
add(Green);
add(Blue);
}
public static void main(String[] args) {
frame = new JFrame();
JPanel row1 = new MyButtons();
JPanel row2 = new MyButtons();
row1.setPreferredSize(new Dimension(250, 100));
row2.setPreferredSize(new Dimension(250, 100));
frame.setLayout(new GridLayout(3,2));
frame.add(row1);
frame.add(row2);
frame.pack();
frame.setVisible(true);
}
}
最佳答案
此代码可以工作,但可能不符合您的预期:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class MyButtons extends JPanel {
//public static JFrame frame;
// static is rarely a solution of problems in a GUI. ToDo! Change!
static JPanel ui = new JPanel(new GridLayout(2, 0, 20, 20));
private JButton Red = new JButton("Red");
private JButton Green = new JButton("Green");
private JButton Blue = new JButton("Blue");
public void InitializeButton() {
Blue.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.BLUE);
}
});
Green.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.GREEN);
}
});
Red.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ui.setBackground(Color.RED);
}
});
}
public MyButtons() {
InitializeButton();
add(Red);
add(Green);
add(Blue);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(250, 100);
}
public static void main(String[] args) {
JFrame frame = new JFrame();
JPanel row1 = new MyButtons();
JPanel row2 = new MyButtons();
//row1.setPreferredSize(new Dimension(250, 100));
//row2.setPreferredSize(new Dimension(250, 100));
//frame.setLayout(new GridLayout(3, 2,10,10));
ui.add(row1);
ui.add(row2);
frame.add(ui);
frame.pack();
frame.setVisible(true);
}
}
注意请学习常见的 Java 命名法(命名约定 - 例如 EachWordUpperCaseClass
、firstWordLowerCaseMethod()
、firstWordLowerCaseAttribute
,除非它是 UPPER_CASE_CONSTANT
)并始终如一地使用它。
关于java - 设置 Action 监听器并更改背景,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36442878/