java - 如何向 JTextArea 添加文本？ java

Question

我的程序中有三个按钮和一个 JTextArea。我想要做的是，当用户按下按钮时，我希望 JTextArea 中显示文本，说明按钮 1 已按下，按钮 2 已按下，依此类推。例如。

JButton button1 = new JButton();
JButton button2 = new JButton();
JButton button3 = new JButton();

JTextArea text = new JTextArea();
JFrame frame = new JFrame();
frame.add(button1);
frame.add(button2);
frame.add(button3);
frame.add(text);
frame.setVisible(true);

我想要做的是，当用户按下按钮 1 时，我希望 JTextArea 具有显示按钮 1 被按下的文本，然后如果用户按下按钮 2，我希望 JTextArea 具有先前的文本和按钮 2 的文本，因此应该显示类似；

button 1 was pressed
button 2 was pressed

编辑:

所以文本就像这样，

button 1 was pressed button 2 was pressed
button 3 was pressed 

如果我有更多按钮，它会看起来像这样

button 1 was pressed button 2 was pressed
button 3 was pressed button 4 was pressed
button 5 was pressed button 6 was pressed

等等。

Answer 1

将 actionListener 添加到将调用的每个按钮

yourTextArea.append("button X was pressed\n");

这是简单的演示

JFrame frame = new JFrame();
frame.setLayout(new FlowLayout());

final JTextArea area = new JTextArea(2,20);
frame.getContentPane().add(area);

JButton button1 = new JButton("press me");
JButton button2 = new JButton("press me");

button1.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        area.append("button 1 was pressed\n");
    }
});
button2.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        area.append("button 2 was pressed\n");
    }
});

frame.getContentPane().add(button1);
frame.getContentPane().add(button2);

frame.setSize(300,300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);

<小时/>

您还可以使用

try {
    area.getDocument().insertString(0,"button 1 was pressed\n", null);
} catch (BadLocationException e1) {
    e1.printStackTrace();
}

而不是

yourTextArea.append("button X was pressed\n");

如果您想在文本区域的开头添加新行。