java - 键入时如何正确删除自动添加的右括号

Question

在 textPaneKeyTyped(java.awt.event.keyEvent evt) 方法中，我编写了一些代码以在键入左括号时自动关闭括号。我添加了一些代码，用于在用户在 textPane 中键入右括号时删除右括号，但它没有执行任何操作

这是一个工作示例:

package test;

import java.awt.event.ActionEvent;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JTextPane;
import javax.swing.KeyStroke;
import javax.swing.text.BadLocationException;


public class NewJFrame extends javax.swing.JFrame {

    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
    }

    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jScrollPane1 = new javax.swing.JScrollPane();
        textPanel = new javax.swing.JTextPane();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        textPanel.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyTyped(java.awt.event.KeyEvent evt) {
                textPanelKeyTyped(evt);
            }
        });
        jScrollPane1.setViewportView(textPanel);

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE)
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(19, 19, 19)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 254, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(27, Short.MAX_VALUE))
        );

        getContentPane().add(jPanel1, java.awt.BorderLayout.CENTER);

        pack();
    }// </editor-fold>

private void textPanelKeyTyped(java.awt.event.KeyEvent evt) {
// TODO add your handling code here:
     Action action1 = new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent e) {
            textModel = (JTextPane) e.getSource();
            try {
                int position2 = textModel.getCaretPosition();
                textModel.getDocument().remove(position2, 1);
                textModel.getDocument().insertString(position2, ")", null);

            } catch (Exception e1) {}
        }

};
    Action action = new AbstractAction() {

            @Override
            public void actionPerformed(ActionEvent e) {
                int position = textModel.getCaretPosition();
                textModel.replaceSelection("()");
                textModel.setCaretPosition(position+1);
            }

    };

    String key =  "typed (";
    String key1 = "typed )";
    textPanel.getInputMap().put(KeyStroke.getKeyStroke(key), key);
    textPanel.getInputMap().put(KeyStroke.getKeyStroke(key1), key1);
    textPanel.getActionMap().put(key, action);
    textPanel.getActionMap().put(key1, action1);


}

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JPanel jPanel1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTextPane textPanel;
    // End of variables declaration
}

自动关闭括号的代码有效.. 问题是右括号的替换:它在有“(”之前打印“)”。如果我能够随时打印“)”，我应该如何编辑我的代码？ 谢谢。

Answer 1

阻止 KeyStroke 的使用绝不是一个好主意。您永远不知道什么时候可能需要手动输入“)”。谁在乎用户是否输入“)”。如果它在语法上不正确，那么他们最终会得到一个编译错误。聪明的用户会意识到，所有需要做的就是键入“(”，然后“)”将为他们输入。

但是，如果在某些情况下您确实想要阻止输入给定字符，您可以使用 Key Bindings 而不是 KeyListener。

例如:

KeyStroke ignore = KeyStroke.getKeyStroke(')');
textPane.getInputMap().put(ignore, "none");

有关 Key Bindings 的更多信息，请阅读 Swig 教程。我在您之前的一个问题中给了您一个链接。将教程链接放在手边以获取基础知识。当您查看本教程的目录(“trail”)时，您会找到关于如何使用键绑定(bind)的部分。

还有你的“(” Action 你可以只使用:

textPane.replaceSelection("()");