如何在JFrame中居中对齐标题？

Question

我有一个带标题的JFrame.我希望中心对齐标题,以便它出现在JFrame标题的中间.

谢谢.

Answer 1

考虑让标题左对齐......但是......这会让你靠近中心.对于可调整大小的帧,您需要在调整大小时重写标题.

JFrame t = new JFrame();
t.setSize(600,300);
t.setFont(new Font("System", Font.PLAIN, 14));
Font f = t.getFont();
FontMetrics fm = t.getFontMetrics(f);
int x = fm.stringWidth("Hello Center");
int y = fm.stringWidth(" ");
int z = t.getWidth()/2 - (x/2);
int w = z/y;
String pad ="";
//for (int i=0; i!=w; i++) pad +=" "; 
pad = String.format("%"+w+"s", pad);
t.setTitle(pad+"Hello Center");

Answer 2

调整@Java42的答案来源，我做了一个“解决方法”来调整JFrame大小时调整标题：

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

import javax.swing.JFrame;


public class JFrameTitleCenter {

    public void createAndShowGUI() {

        JFrame frame = new JFrame();
        frame.setPreferredSize(new Dimension(300, 200));
        frame.setTitle("Hello Center");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.addComponentListener(new ComponentAdapter() {
            @Override
            public void componentResized(ComponentEvent e) {
                titleAlign(frame);
            }

        });

        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

    }

    private void titleAlign(JFrame frame) {

        Font font = frame.getFont();

        String currentTitle = frame.getTitle().trim();
        FontMetrics fm = frame.getFontMetrics(font);
        int frameWidth = frame.getWidth();
        int titleWidth = fm.stringWidth(currentTitle);
        int spaceWidth = fm.stringWidth(" ");
        int centerPos = (frameWidth / 2) - (titleWidth / 2);
        int spaceCount = centerPos / spaceWidth;
        String pad = "";
        pad = String.format("%" + (spaceCount - 14) + "s", pad);
        frame.setTitle(pad + currentTitle);

    }

    public static void main(String[] args) {

        EventQueue.invokeLater(() -> {
            new JFrameTitleCenter().createAndShowGUI();
        });
    }
}

在职的：