将ActionListener添加到JTextArea的解决方法

Question

我有一个程序在一个JTextArea中获取带有文件路径的输入字符串,然后将其内容加载到第二个JTextArea.问题是当使用JTextArea时,我无法添加一个actionListener,它将在离开此字段时在第二个JTextArea中加载内容.如何解决这个问题？

protected JTextArea inputField, outputField;

public Main(){
    super(new BorderLayout());
    inputField = new JTextArea(5, 20);
    outputField = new JTextArea(2, 20);
    //inputField.addActionListener(this);
    inputField.setEditable(false);
    JScrollPane scroller2 = new JScrollPane(inputField);
    JScrollPane scroller1 = new JScrollPane(outputField);

    this.add(scroller1, BorderLayout.WEST);
    this.add(scroller2, BorderLayout.EAST);
}

public void actionPerformed(ActionEvent evt) {
    String text = inputField.getText();
    (loading contents of file)
}

Answer 1

你不想要一个actionListener,你想要一个FocusListener.

JTextArea text = ...;
text.addFocusListener(new FocusListener() {
    public void focusGained(FocusEvent e) {}
    public void focusLost(FocusEvent e) {
        // Load your content.
    }

});