java - 如何更改文本字段中的插入符号？

Question

有没有办法将文本字段中闪烁的插入符号更改为另一个字符？我想把它从“|”改成到“>”。我所知道的就是改变颜色。

textField.setCaretColor(Color.WHITE);  

谢谢

Answer 1

基本上，您需要创建自己的 Caret 并绘制您想要的任何内容...

import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.GridBagLayout;
import java.awt.Rectangle;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.TextUI;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultCaret;
import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.JTextComponent;
import javax.swing.text.Position;

public class CaretExample {

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

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

                JTextField field = new JTextField(10);
                field.setCaret(new MyCaret());

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new GridBagLayout());
                frame.add(field);
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class MyCaret extends DefaultCaret {

        private String mark = "<";

        public MyCaret() {
            setBlinkRate(500);
        }

        @Override
        protected synchronized void damage(Rectangle r) {
            if (r == null) {
                return;
            }

            JTextComponent comp = getComponent();
            FontMetrics fm = comp.getFontMetrics(comp.getFont());
            int textWidth = fm.stringWidth(">");
            int textHeight = fm.getHeight();
            x = r.x;
            y = r.y;
            width = textWidth;
            height = textHeight;
            repaint(); // calls getComponent().repaint(x, y, width, height)
        }

        @Override
        public void paint(Graphics g) {
            JTextComponent comp = getComponent();
            if (comp == null) {
                return;
            }

            int dot = getDot();
            Rectangle r = null;
            try {
                r = comp.modelToView(dot);
            } catch (BadLocationException e) {
                return;
            }
            if (r == null) {
                return;
            }

            if ((x != r.x) || (y != r.y)) {
                repaint(); // erase previous location of caret
                damage(r);
            }

            if (isVisible()) {
                FontMetrics fm = comp.getFontMetrics(comp.getFont());
                int textWidth = fm.stringWidth(">");
                int textHeight = fm.getHeight();

                g.setColor(comp.getCaretColor());
                g.drawString(mark, x, y + fm.getAscent());
            }
        }

    }
}

这是基于这个 example