java - 如何在按下按钮之前暂停方法？

Question

我正在设计一个包含多个组件的软件——每个组件都有自己的 Action 监听器。例如，我有一个带有卡片布局的 JPanel，其中包含 10 张卡片 - 每张都有自己的 JPanel 和用途。

一侧有多个按钮，I.E.登录、注销、设置等

当我单击“登录”时，它将使用登录 JPanel 对象的 Login() 方法切换到卡片，我希望它在其中等待按钮单击 I.E.在继续 Login() 方法并设置当前用户之前登录、新建用户或取消。

是否有一种方法可以暂停程序，直到单击其中一个按钮从中检索数据？ (有点像 JOptionPane.showInputMessage(null,"INPUT STRING") 等你的方式)

我的代码如下:框架:

/**
 * Frame design
 */


public class Frame extends JFrame{
JPanel LeftSide, UpperRightSide;
EmployeeAdder employAdd;
ArrayList<ServiceView> serviceViewers;
ChartViewer viewChart;
PayByView viewPayBy;
SettingsViewer viewSettings;
LoginViewer viewLogin;
CategoryView viewCategory;
ServiceAdder serviceAdd;
Directory directory;
Employee currentEmployee;
ChargeViewer viewCharge;
JButton Login, Logout, Settings;
CardLayout LeftCard,RightCard;
String currentCard,currentRightCard;
ButtonListen listen;
public static String CARDCAT = "Category View";
public static String CARDPAY = "Pay By";
public static String CARDCHART = "Chart View";
public static String CARDLOGIN = "Log-in View";
public static String CARDSERVICEADD = "Service Adder";

Frame(){
    listen = new ButtonListen();
    //-------Current Card--------------------
    currentCard = CARDCAT;
    currentRightCard = "CHARGE";
    //-----First Find Directory Folder-------
    startDirectory();
    //-----User Interface--------------------
    //-------Left Side-----------------------
    LeftSide = new JPanel();
    LeftCard = new CardLayout();
        LeftSide.setLayout(LeftCard);
        viewPayBy = new PayByView();
        viewLogin = new LoginViewer();
        viewChart = new ChartViewer();
        viewCategory = new CategoryView();
        employAdd = new EmployeeAdder();
        serviceAdd = new ServiceAdder();
        LeftSide.add(viewCategory,"CAT");
        LeftSide.add(viewChart, "CHA");
        LeftSide.add(viewLogin,"LOG");
        LeftSide.add(viewPayBy,"PAY");
        LeftSide.add(employAdd,"EMA");
        LeftSide.add(serviceAdd,"SEA");
        LeftCard.show(LeftSide, "CAT");
        viewCategory.setEnabled(false);
        LeftSide.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.BLACK),currentCard));
        serviceViewers = new ArrayList<ServiceView>();

    //--------Right Side---------------------
    JPanel RightSide = new JPanel();
        RightSide.setLayout(new BorderLayout());
        UpperRightSide = new JPanel();
        RightCard = new CardLayout();
        UpperRightSide.setLayout(RightCard);
            viewSettings = new SettingsViewer();
            viewCharge = new ChargeViewer();
            viewCharge.setEnabled(false);
            UpperRightSide.add(viewCharge,"CHARGE");
            UpperRightSide.add(viewSettings,"SETTINGS");
            UpperRightSide.setPreferredSize(new Dimension(350,500));
        RightSide.add(UpperRightSide,BorderLayout.NORTH);
        //--------Buttons at the bottom Panel---
        JPanel Buttons = new JPanel();
            Buttons.setLayout(new GridLayout(3,1));
            Login = new JButton("LOG-IN");
                Login.addActionListener(listen);
            Logout = new JButton("LOG OUT");
                Logout.addActionListener(listen);
            Settings = new JButton("Settings");
                Settings.addActionListener(listen);
            Buttons.add(Login);
            Buttons.add(Logout);
            Buttons.add(Settings);
            Buttons.setPreferredSize(new Dimension(350,150));
        RightSide.add(Buttons,BorderLayout.SOUTH);
        RightSide.setSize(new Dimension(400,200));
    //------Other Stuff--------------------------

    //-----add Panels----------------------------
        setLayout(new BorderLayout());
        add(LeftSide,BorderLayout.WEST);
        add(RightSide,BorderLayout.EAST);
}


private void Login(){
    LeftCard.show(LeftSide, "LOG");

    //----I WANT IT TO WAIT HERE FOR AN ACTION-------
    int clicked = viewLogin.getClicked();
        if (clicked==LoginViewer.NEWUSER){
            NewUser();
        }else if (clicked==LoginViewer.LOGIN){
            if (viewLogin.checkPassword()){
                currentEmployee = directory.getEmployee(viewLogin.getSelectedName());
                viewCategory.setEnabled(true);
                viewCharge.setEnabled(true);
                viewCharge.refreshName(currentEmployee.getName());
                LeftCard.show(LeftSide, "CAT");
            }
        }else if (clicked==LoginViewer.CANCEL){
            LeftCard.show(LeftSide, "CAT");
        }


}




public class ButtonListen implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {
        if (!viewLogin.isWaiting()){
        if (e.getSource()==Login){
            if (currentCard.equals(CARDLOGIN)){
                LeftCard.show(LeftSide,"CAT");
                currentCard = CARDCAT;

            }else{
                Login();
                currentCard = CARDLOGIN;
            }
        }else{
            //Don't change the screen
        }
        }

    }

}

}

我的 LoginViewer 代码:

public class LoginViewer extends JPanel{
JComboBox User;
JPasswordField passField;
JButton NewUser, Login, Cancel;
Hashtable<String,String> namespass; //names and password
private int clicked = -1;
ButtonListen listen;
public static int NEWUSER = 1;
public static int LOGIN = 0;
public static int CANCEL = 2;
boolean waiting;

LoginViewer(){
    waiting = false;
    //---------------------------------------
    setPreferredSize(new Dimension(100,100));
    listen = new ButtonListen();
    namespass = new Hashtable<String,String>();
    //----------Panel Design-------------------
    JPanel Center = new JPanel();
        Center.setLayout(new GridLayout(3,3));
    User = new JComboBox();
    passField = new JPasswordField();
    NewUser = new JButton("New User");
        NewUser.addActionListener(listen);
    Login = new JButton("Login");
        Login.addActionListener(listen);
    Cancel = new JButton("Cancel");
        Cancel.addActionListener(listen);
    Center.add(new JLabel("Choose User"));
    Center.add(User);
    Center.add(new JLabel(""));
    Center.add(new JLabel("Type Password"));
    Center.add(passField);
    Center.add(new JLabel(""));
    Center.add(Login);
    Center.add(NewUser);
    Center.add(Cancel);
    Center.setPreferredSize(new Dimension(300,300));
    Center.setMaximumSize(new Dimension(100,100));
    Center.setAlignmentX(CENTER_ALIGNMENT);
    setAlignmentX(CENTER_ALIGNMENT);
    setLayout(new BoxLayout(this,BoxLayout.X_AXIS));
    add(Box.createHorizontalGlue());
    add(Center);
    add(Box.createHorizontalGlue());
}


public void uploadUserNames(Hashtable<String,String> names){
    namespass.clear();
    namespass.putAll(names);
    User.removeAllItems();
    Enumeration<String> name = names.keys();
    while (name.hasMoreElements()){
        User.addItem(name.nextElement());
    }
}

public boolean checkPassword(){
    boolean value = false;
    String key = User.getSelectedItem().toString();
    if (passField.getPassword().length==4){
        if (namespass.get(key).equals(String.valueOf(passField.getPassword()))){
            value = true;
        }
    }
    return value;
}

public String getSelectedName(){
    return User.getSelectedItem().toString();
}

public boolean isWaiting(){
    return waiting;
}

public int getClicked(){
    waiting = true;
    return clicked;
}

public class ButtonListen implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e) {

        waiting = false;
        if (e.getSource()==NewUser){
            clicked = 1;
        }else if (e.getSource()==Login){
            clicked = 0;
        }else if (e.getSource()==Cancel){
            clicked = 2;
        }

    }

}
}

或者只使用一个 Action 监听器来监听所有对象的按钮是否更容易？

有很多按钮...

注意:在我知道如何使它工作之前，有些方法是不完整的或测试方法......

Answer 1

您不想在 Swing GUI 中使用线性控制台类型的代码。相反，对于事件驱动的 GUI 程序，您将希望让用户交互改变程序的状态，然后让程序的行为取决于状态。例如，不是让登录方法暂停，而是让它做一些内务处理——改变程序的状态以准备好接受登录尝试——然后在你计划“等待”的地方退出登录方法。然后将用于登录的其余代码驻留在登录按钮的 ActionListener 中。

顺便说一句，您发布了很多代码，其中 95% 与您的问题无关，因此只会分散我们的注意力并阻止我们阅读代码和理解你的问题的细节。将来，考虑创建和发布 sscce ，您将代码压缩为仍然可以编译的最小位，没有与您的问题无关的额外代码，但仍然为我们演示了您的问题。