如何在 Java JEditorPane 中自动将小写字母更新为大写字母? [英] How to automatically update small letter characters to capital letter in Java JEditorPane?

问题描述

所以我想将所有输入的字符自动转换为大写.

So I want to automatically convert all entered characters to uppercase.

这是代码的相关部分:

editorPane = new JEditorPane();
editorPane.getCaret().setBlinkRate(0);
this.keyListener = new UIKeyListener(editorPane);
editorPane.addKeyListener(keyListener);

而 UIKeyListener 类我只提供 keyReleased 函数，因为其他部分只是样板代码

And the UIKeyListener Class I am only providing the keyReleased function as other part is just boilerplate code

@Override
public void keyReleased(KeyEvent e) {
    capitalizeCode();
}

private void capitalize() {
    int prevCarerPosition = editorPane.getCaretPosition();
    editorPane.setText(editorPane.getText().toUpperCase());
    editorPane.setCaretPosition(prevCarerPosition);
}

这基本上没问题，但问题是:-

This is mostly OK but the problems are :-

• 我无法选择文本
• 每次我输入字符时，它们首先以小写字母出现，然后变成大写字母

现在，如果我从 keyTyped 函数调用大写函数，第一个问题就解决了，但有一个新问题:最后输入的字母仍然很小

Now The first problem is solved if I call the capitalize function from keyTyped function but there there is a new problem : the last typed letter remains small

而且我还想问一下，我们是否可以在不听键事件的情况下执行此操作，例如默认情况下编辑器窗格只接受大写字母?

And I also want to ask whether can we do this without listening to keyevents like by default the editorpane will only accept capital letters?

推荐答案

不要使用 KeyListener.

Don't use a KeyListener.

更好的方法是使用 DocumentFilter.

无论文本是键入还是粘贴到文本组件中，这都将起作用.

This will work whether text is typed or pasted into the text component.

import java.awt.*;
import javax.swing.*;
import javax.swing.text.*;

public class UpperCaseFilter extends DocumentFilter
{
    public void insertString(FilterBypass fb, int offs, String str, AttributeSet a)
        throws BadLocationException
    {
        replace(fb, offs, 0, str, a);
    }

    public void replace(FilterBypass fb, final int offs, final int length, final String text, final AttributeSet a)
        throws BadLocationException
    {
        if (text != null)
        {
            super.replace(fb, offs, length, text.toUpperCase(), a);
        }
    }

    private static void createAndShowGUI()
    {
        JTextField textField = new JTextField(10);
        AbstractDocument doc = (AbstractDocument) textField.getDocument();
        doc.setDocumentFilter( new UpperCaseFilter() );

        JFrame frame = new JFrame("Upper Case Filter");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout( new java.awt.GridBagLayout() );
        frame.add( textField );
        frame.setSize(220, 200);
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }

    public static void main(String[] args) throws Exception
    {
        EventQueue.invokeLater( () -> createAndShowGUI() );
    }
}

过滤器可用于任何文本组件.

The filter can be used on any text component.

请参阅 Swing 教程中关于实施文档过滤器的部分 了解更多信息.

See the section from the Swing tutorial on Implementing a DocumentFilter for more information.

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