Java Swing : Get text value from JOptionPane

Question

我想创建一个在 POS 系统中使用的新窗口。用户输入的是客户拥有的金额，窗口必须显示兑换金额。我是 JOptionPane 功能的新手(我一直在使用 JAVAFX，但它有所不同)。

这是我的代码:

public static void main(String[] argv) throws Exception {
    String newline = System.getProperty("line.separator");
    int cost = 100;
    int amount = Integer.parseInt(JOptionPane.getText()) // this is wrong! This needs to come     from user input box in the same window.
    JFrame frame = new JFrame();
    String message = "Enter the amount of money"+newline+"The exchange money is: "+amount-cost;
    String text = JOptionPane.showInputDialog(frame, message);
    if (text == null) {
      // User clicked cancel
}

有什么建议吗？

Answer 1

使用输入对话框获取用户输入

public static void main(String[] argv) throws Exception {
      //JFrame frame = new JFrame();
      //frame.setVisible(true);
      int cost = 100;
      JLabel l=new JLabel("The exchange money is");

      JPanel p=new JPanel(new GridLayout(1, 2, 10, 10));
      p.setPreferredSize(new Dimension(400, 50));
      JTextField t=new JTextField("Enter the amount of money");
      t.addKeyListener(new java.awt.event.KeyAdapter() {
        public void keyReleased(java.awt.event.KeyEvent evt) {
            try{
            int amount=Integer.parseInt(t.getText());
            l.setText("The exchange money is: \n" + (amount - cost));
            }catch(Exception ex){
               // ex.printStackTrace();
            }
        }
      });
      p.add(t);
      p.add(l);

    int option = JOptionPane.showConfirmDialog(null,p,"JOptionPane Example : ",JOptionPane.OK_CANCEL_OPTION,JOptionPane.PLAIN_MESSAGE);
    if(option==0){
        System.out.println("ok clicked");
    }else{
        System.out.println("cancel clicked");
    }
}