Question

我尝试搜索某种互动JLabel。我希望它看起来像这样：

我不确定这是什么叫，或者我在哪里可以找到有关显示此内容的信息。我希望它在按下+/-时打印刷新的数字。我让它在eclipse控制台上打印，但我不确定如何将它打印到JFrame。

以下是一些代码：

String input = JOptionPane.showInputDialog("Please enter the number of laps.");

    numLaps = Integer.parseInt(input);

    //frame creation
    JFrame f = new JFrame("Number of Laps");
    f.setSize(550, 450);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setLayout(null);

    // label creation
    JLabel label = new JLabel("You entered " + numLaps + " laps. Press + to add a lap. Press - to subtract a lap.", SwingConstants.CENTER);
    label.setBounds(0,0,500,300);
    f.add(label);
    //display window

    f.setVisible(true);


    //button creation add
    JButton add = new JButton ("+");
    add.setBounds(350,250,50,50);
    add.setPreferredSize(new Dimension(50,50));
    add.addActionListener( new ActionListener()
    {

        @Override
        public void actionPerformed(ActionEvent e) {
            // what happens when button is pressed
            //numLaps++;
            addToLap();
            System.out.println(numLaps);
        }

    });
    f.add(add);

  //button creation subtract
        JButton sub = new JButton ("-");
        sub.setBounds(100,250,50,50);
        sub.setPreferredSize(new Dimension(50,50));

          sub.addActionListener( new ActionListener()
          {

            @Override
            public void actionPerformed(ActionEvent e) {
                // what happens when button is pressed
                //numLaps--;
                subToLap();
                System.out.println(numLaps);
            }

          });
          f.add(sub);

＆安培; add / sub方法：

private static void addToLap() {
    // TODO Auto-generated method stub
    numLaps++;
}
private static void subToLap() {
    // TODO Auto-generated method stub
    numLaps--;
}

Answer 1

您可以尝试以下方法：

private int numLaps = 0 // Or the number you want initialize with

然后在你的方法中应该将numLaps值赋予JLabel，如下所示：

this.myLabel.setText(String.valueOf(numLaps));

我希望它有所帮助。

在JFrame中创建实时计数器

1 个答案: