我对Java和编程领域还是相当陌生，我遇到了一个似乎无法解决的问题。在我的程序中，我有两个JPanels，分别包含一个JLabel和三个JButton，并且面板在框架内的GridLayout中排列。
我的问题是，我无法将JLabel中的文本放在第一个JPanel的中心。最初，我使用的是FlowLayout，将它按我想要的方向排列，但是当包含的String变得超过一定长度时，它就离开了屏幕。在当前设置下，文本会适当地换行，但始终从左对齐开始。
我已经在站点周围搜索并查看了多个答案-的确，我认为我的问题可以通过使用HTML来解决（这确实解决了包装问题，并且将第二行集中对齐，如下所示）-但我仍然可以t找出如何将第一条线居中对齐。
这是我当前的代码：
import java.awt.*;
import javax.swing.*;
public class UITests extends JFrame {
private JLabel txtWindow = new JLabel();
private JButton jb1 = new JButton();
private JButton jb2 = new JButton();
private JButton jb3 = new JButton();
private final Font font = new Font("Serif", Font.PLAIN, 12);
public UITests() {
//Creating the top panel for the JLabel
JPanel panelA = new JPanel(new BorderLayout());
txtWindow.setForeground(Color.white);
txtWindow.setFont(new Font("", Font.PLAIN, 15));
txtWindow.setText("<html><div style='text-align: center;'>" + "Mellon"
+ "</div></html>");
panelA.setBackground(Color.BLACK);
panelA.add(txtWindow, BorderLayout.NORTH);
//Creating the bottom panel for the JButtons
JPanel panelB = new JPanel(new GridLayout(3, 1, 5, 5));
//setting up button properties
jb1.setBackground(Color.BLACK);
jb2.setBackground(Color.BLACK);
jb3.setBackground(Color.BLACK);
jb1.setForeground(Color.white);
jb2.setForeground(Color.white);
jb3.setForeground(Color.white);
jb1.setFocusPainted(false); //Stopping highlighting of button
jb2.setFocusPainted(false);
jb3.setFocusPainted(false);
jb1.setFont(font);
jb2.setFont(font);
jb3.setFont(font);
panelB.setBackground(Color.BLACK);
panelB.add(jb1);
panelB.add(jb2);
panelB.add(jb3);
setLayout(new GridLayout(2, 1, 0, 0));
add(panelA);
add(panelB);
setTitle("Screen");
setSize(500, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
new UITests();
}
}
任何帮助，将不胜感激，如果存在非常类似的问题，我们深表歉意；我尽力找到它！
只需使用txtWindow.setHorizontalAlignment(JLabel.CENTER);，就像这样：
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
private JLabel txtWindow = new JLabel();
private JButton jb1 = new JButton();
private JButton jb2 = new JButton();
private JButton jb3 = new JButton();
private final Font font = new Font("Serif", Font.PLAIN, 12);
public Main() {
//Creating the top panel for the JLabel
JPanel panelA = new JPanel(new BorderLayout());
txtWindow.setForeground(Color.white);
txtWindow.setFont(new Font("", Font.PLAIN, 15));
txtWindow.setText("Mellon");
txtWindow.setHorizontalAlignment(JLabel.CENTER);
panelA.setBackground(Color.BLACK);
panelA.add(txtWindow, BorderLayout.NORTH);
//Creating the bottom panel for the JButtons
JPanel panelB = new JPanel(new GridLayout(3, 1, 5, 5));
//setting up button properties
jb1.setBackground(Color.BLACK);
jb2.setBackground(Color.BLACK);
jb3.setBackground(Color.BLACK);
jb1.setForeground(Color.white);
jb2.setForeground(Color.white);
jb3.setForeground(Color.white);
jb1.setFocusPainted(false); //Stopping highlighting of button
jb2.setFocusPainted(false);
jb3.setFocusPainted(false);
jb1.setFont(font);
jb2.setFont(font);
jb3.setFont(font);
panelB.setBackground(Color.BLACK);
panelB.add(jb1);
panelB.add(jb2);
panelB.add(jb3);
setLayout(new GridLayout(2, 1, 0, 0));
add(panelA);
add(panelB);
setTitle("Screen");
setSize(500, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}
这将使文本在标签中居中。然后，您无需添加HTML，因此也可以直接单击setText("Melon");，而不是使用HTML。
对于短字符串和长字符串，尽管尝试将居中的HTML div标签和setHorizontalAlignment(JLabel.CENTER);调用结合起来，例如：
import java.awt.*;
import javax.swing.*;
public class Main extends JFrame {
private JLabel txtWindow = new JLabel();
private JButton jb1 = new JButton();
private JButton jb2 = new JButton();
private JButton jb3 = new JButton();
private final Font font = new Font("Serif", Font.PLAIN, 12);
public Main() {
//Creating the top panel for the JLabel
JPanel panelA = new JPanel(new BorderLayout());
txtWindow.setForeground(Color.white);
txtWindow.setFont(new Font("", Font.PLAIN, 15));
final String text = "Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon Mellon";
txtWindow.setText("<html><div style='text-align: center;'>" + text + "</div></html>");
txtWindow.setHorizontalAlignment(JLabel.CENTER);
panelA.setBackground(Color.BLACK);
panelA.add(txtWindow, BorderLayout.NORTH);
//Creating the bottom panel for the JButtons
JPanel panelB = new JPanel(new GridLayout(3, 1, 5, 5));
//setting up button properties
jb1.setBackground(Color.BLACK);
jb2.setBackground(Color.BLACK);
jb3.setBackground(Color.BLACK);
jb1.setForeground(Color.white);
jb2.setForeground(Color.white);
jb3.setForeground(Color.white);
jb1.setFocusPainted(false); //Stopping highlighting of button
jb2.setFocusPainted(false);
jb3.setFocusPainted(false);
jb1.setFont(font);
jb2.setFont(font);
jb3.setFont(font);
panelB.setBackground(Color.BLACK);
panelB.add(jb1);
panelB.add(jb2);
panelB.add(jb3);
setLayout(new GridLayout(2, 1, 0, 0));
add(panelA);
add(panelB);
setTitle("Screen");
setSize(500, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
new Main();
}
}
希望这是您想要的。