java - 是否可以从初始化的类外部更改对象实例？

Question

我可能以错误的方式处理这件事。请赐教。提前感谢!!!

void initialize() {
more code...
JEditorPane textPane = new JEditorPane();
textPane.setEditable(false);
textPane.setBackground(Color.LIGHT_GRAY);
textPane.setText(" THE MESSAGE I WANT TO CHANGE FROM OUTSIDE initialize()");
more code....

public static void SomePrintClass(){
JEditorPane textPane = new JEditorPane();
textPane.setText("SOME NEW TEXT );        // I am aware this doesn't work 
//but is there a way it can be made to work???
more code.....

Answer 1

我猜您只想更改任何其他类中 JEditorPane 的文本。如果是这样那就很简单了。 使 JEditorPane 静态并使用类的名称调用其 setText() 方法。例如。

头等舱。

public class First extends JFrame {

    static JEditorPane ep;
    First() {
        ep = new JEditorPane();
        setSize(new Dimension(200, 200));
        ep.setText("I expect to receive some text.");
        add(ep);
        setVisible(true);
    }

    @Override
    public void paintComponents(Graphics g) {
        super.paintComponents(g);
    }
}

二等。

public class Second extends JFrame {

    JButton btn;
    JTextField jtf = new JTextField(16);
    JEditorPane ep;

    Second() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        btn = new JButton("Send above Text.");
        setSize(new Dimension(200, 200));
        btn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
               ep = First.ep;
               ep.setText(jtf.getText());
               ep.setForeground(Color.red);
            }

        });
        this.setLayout(new FlowLayout());
        add(jtf);
        add(btn);
        setVisible(true);
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {
            First so;

            @Override
            public void run() {
                new Second();
                so = new First();
            }
        });
    }
}