java - 一名 Java 学徒尝试从 System.out.println 迁移到 swing

Question

我终于尝试将旧的控制台程序迁移到 Swing，以便更轻松地分发给我的 friend 。为此，我尝试编写一个可以扩展的 ConsoleFrame 类，而不是 JFrame，这将允许我尽可能轻松地将旧代码与 Swing 连接。 out(String) 似乎有效，但 inln() 让我难住了。

//Imports not included
public class ConsoleFrame extends JFrame
{
    protected JTextField in;
    protected JTextArea out;

    public ConsoleFrame(){
        this("Console Frame", 80, 10);
    }
    public ConsoleFrame(int cols){
        this("Console Frame", cols, 10);
    }
    public ConsoleFrame(int cols, int rows){
        this("Console Frame", cols, rows);
    }
    public ConsoleFrame(String title){
         this(title, 80, 10);
    }
    public ConsoleFrame(String title, int cols, int rows){
        in = new JTextField();
        in.setEditable(true);
        in.setColumns(cols);

        out = new JTextArea();
        out.setEditable(false);
        out.setColumns(cols);
        out.setRows(rows);
        out.setWrapStyleWord(true);

        setTitle(title);
        setVisible(true);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        add(in, BorderLayout.PAGE_END);
        add(out, BorderLayout.PAGE_START);
        pack();
    }

    protected void out(String o) {
        out.append(o);
    }
    protected void outln(String o) {
            out(o + BIO.$ln);    //BIO.$ln == System.getProperty("line.separator")
    }

    /*
     * This is supposed to halt execution until the user presses enter, then return the text entered in the JTextField named in.
     */
    protected String inln() {
        in.setEnabled(true);
        KeyListener enter = new KeyListener() {
            @Override
            public void keyTyped(KeyEvent paramKeyEvent) {
                if(paramKeyEvent.getKeyCode() == KeyEvent.VK_ENTER) {
                     if(in.hasFocus()) {
                         in.setEnabled(false);
                     }
                }
            }
            @Override public void keyPressed(KeyEvent paramKeyEvent) {}
            @Override public void keyReleased(KeyEvent paramKeyEvent) {}    
        };
        in.addKeyListener(enter);
        while(true){    //This loop is intended to interrupt flow until in.isEnabled()==false, which will only happen when the enter key is typed.
            if(in.isEnabled()==false){
                String result = in.getText();
                in.setText("");
                in.setCaretPosition(0);
                this.removeKeyListener(enter);
                in.setEnabled(true);
                return result;
            }
        }
    }
}

测试程序:

public class Tester extends ConsoleFrame
{
    public static void main(String[] args) {
        new Tester();
    }
    public Tester() {
        super("Test", 60, 30);
        out(inln());
    }
}

Answer 1

不知道它是否能解决您的问题，但您不应该使用 KeyListner。

JTextField 被设计为使用 ActionListener 来处理 Enter 键。