JTextArea 中的文本更改事件?如何? [英] Text Changed event in JTextArea? How to?

问题描述

我一直在尝试为我的 JTextArea 创建一个文本更改事件处理机制.为了我的目的，每当 JTextArea 的文本发生变化时，必须触发一个事件.我尝试使用 KeyListener 接口，这是我的代码.

I have been trying to make a text changed event handling mechanism for my JTextArea. For my purposes an event has to be fired whenever there is a change in the text of the JTextArea. I tried using the KeyListener interface and here is my code for that.

txtArea.addKeyListener(new KeyListener() {

    @Override
    public void keyTyped(KeyEvent arg0) {

    }

    @Override
    public void keyReleased(KeyEvent arg0) {
        // TODO Auto-generated method stub

    }

    @Override
    public void keyPressed(KeyEvent arg0) {
        currentText = text.getText();
        if (currentText == textString)
            JOptionPane.showMessageDialog(null, "Correct");

    }
});

当 textarea 的文本与硬编码文本匹配时什么也没有发生.如何为此创建事件更改事件.
这个目标可以通过 PropertyChangedListener 实现吗?如果可以，那怎么做?

Nothing happened when the textarea's text matched the hardcoded text. How can an event changed event be made for this.
Can this objective be achieved with a PropertyChangedListener? If it can, then how?

推荐答案

我会通过 getDocument()(实际上是一个普通文档)获取 JTextArea 的文档并使用 DocumentListener 以侦听更改.通过这种方式，您可以从击键以及复制/粘贴/剪切事件中捕获更改.

I would get the JTextArea's Document via getDocument() (a PlainDocument actually) and use a DocumentListener to listen for changes. This way you'd capture changes from key strokes and also from copy/paste/cut events.

这篇关于JTextArea 中的文本更改事件?如何?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！