如何有效地使用cardlayout在java中，以便从各种面板构造内使用面板上的按钮开关如何有效地使

2019-05-12 03:55发布

站内文章 / 前沿技术
73 0 0

我是新来使用cardlayout，我对如何实现它的一些问题。 我首先想知道实现cardlayout，这样我可以从面板切换到面板的最佳途径。 我的主要问题是如何使用我的面板的构造函数内的按钮从面板切换到面板。 我刚开始今天在这个项目上工作，所以你会看到一些代码，没有完成或没有意义。 我第一次尝试，使我所有的类继承的JFrame，但导致多个不必要的窗口。 如果我能得到关于如何有效地使用cardlayout以及如何我的其他面板的构造函数中切换使用按钮面板某种例子。 我使用cardlayout尝试只工作了，我在我的GUI类中创建但是这不是我想要的结果按钮。 如果你能和在此先感谢，请帮助。

这是我的主类。 

public class controller{
    public static void main(String[] args){

        new Gui();


    }
}

这是我的GUI类。 

import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Gui extends JFrame{
    homePage home = new homePage();
    public JPanel loginPanel = new textEmailLog(), 
    registerPanel = new Register(),
    homePanel = new homePage(), viewPanel  = new emailView(),
    loadPanel = new loadEmail(), contentPanel = new JPanel(new CardLayout());
    CardLayout cardLayout = new CardLayout();


    public Gui(){
        super("Email Database Program");
        setSize(700,700);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        contentPanel.setLayout(cardLayout);

        contentPanel.add(loginPanel, "Login");
        contentPanel.add(registerPanel, "Register");
        contentPanel.add(homePanel, "Home");
        contentPanel.add(viewPanel, "View");
        contentPanel.add(loadPanel, "Load");
        this.setContentPane(contentPanel);

        cardLayout.show(contentPanel, "Login");


        setVisible(true);


    }

我的登录面板类

import java.awt.CardLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

//panel has been added
public class textEmailLog extends JPanel{
        JPanel logGui = null;
        JButton registerBut, logBut;
        JTextField Login;

    public textEmailLog(){
        //default characteristics
        setSize(700,700);
        setName("Email Database");
        //setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        //Labels for username and password
        JLabel userLab = new JLabel("Username");
        JLabel pwLab = new JLabel("Password");

        //textfields for username and password
        Login = new JTextField("", 15);
        JPasswordField Password = new JPasswordField("", 15);
        Password.setEchoChar('*');

        //login button that confirms username and password
        logBut = new JButton("Login");
        logBut.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                //needs regex checks prior to logging in 

                if(e.getSource() == logBut){
                    /* Change the panel to the homepage
                    if(Login.getText().equals() && Password.getText().equals()){

                    }
                */  
                    new homePage();
                }


            }
        });

        registerBut = new JButton("Register");
        registerBut.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == registerBut){
                    //Change the panel to the register panel
                }
            }

        });

        //Box layout for organization of jcomponents
        Box verticalContainer = Box.createVerticalBox();
        Box horizontalContainer = Box.createHorizontalBox();
        Box mergerContainer = Box.createVerticalBox();


        //add to panel
        verticalContainer.add(Box.createVerticalStrut(300));//begin relative to the center
        verticalContainer.add(userLab);//Login label and text
        verticalContainer.add(Login);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(pwLab);//password label and text
        verticalContainer.add(Password);
        verticalContainer.add(Box.createVerticalStrut(5));
        horizontalContainer.add(registerBut);//register button
        horizontalContainer.add(Box.createHorizontalStrut(5));
        horizontalContainer.add(logBut);//login button

        //combines both the vertical and horizontal container
        mergerContainer.add(verticalContainer);
        mergerContainer.add(horizontalContainer);
        add(mergerContainer);
        //this.add(logGui);
        setVisible(true);

    }

}

我注册面板类

    import java.awt.Color;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;

    import javax.swing.Box;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JPanel;
    import javax.swing.JPasswordField;
    import javax.swing.JTextField;

    //No Panel addition
    public class Register extends JPanel{
            JButton submit, previous;
            JLabel firstLab, lastLab, userLab, passwordLab, repassLab, address, emailAdd, errorLabel;
            JTextField firstText, lastText, userText, addText, emailAddText;
            JPasswordField passwordText, repassText;

        public Register(){
            setSize(700,700);
            //setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


            //register values and their labels and textfields
            firstLab = new JLabel("First Name: ");
            firstText = new JTextField("", 25);
            lastLab = new JLabel("Last Name: ");
            lastText = new JTextField("", 40);
            userLab = new JLabel("Username: ");
            userText = new JTextField("", 25);
            passwordLab = new JLabel("Password: ");
            passwordText = new JPasswordField("", 25);
            passwordText.setEchoChar('*');
            repassLab = new JLabel("Confirm Password");
            repassText = new JPasswordField("", 25);
            repassText.setEchoChar('*');
            address = new JLabel("Address: ");
            addText = new JTextField("", 50);
            emailAdd = new JLabel("Email Address: ");
            emailAddText = new JTextField("", 50);

            //error message for reigstration issues
            errorLabel = new JLabel();
            errorLabel.setForeground(Color.red);

            submit = new JButton("Submit");

            submit.addActionListener(new ActionListener(){

                @SuppressWarnings("deprecation")
                public void actionPerformed(ActionEvent e) {
                    // TODO Auto-generated method stub
                    if(e.getSource() == submit){
                        //confirm with regex methods and if statements that have been created and need to be created
                        if(firstText.getText().length() == 0){
                            errorLabel.setText("*You have not entered a first name!");
                        }else
                        if(lastText.getText().length() == 0){
                            errorLabel.setText("*You have not entered a last name!");
                        }else
                        if(userText.getText().length() == 0){
                            errorLabel.setText("*You have not entered a username!");
                        }else
                        if(passwordText.toString().length() == 0){
                            errorLabel.setText("*You have not entered a Password!");
                        }else
                        if(repassText.toString().length() == 0){    
                            errorLabel.setText("*You have not matched your password!");
                        }
                        if(addText.getText().length() == 0){
                            errorLabel.setText("*You have not entered an address!");
                        }else
                        if(emailAddText.getText().length() == 0){
                            errorLabel.setText("*You have not entered an Email address!");
                        }else
                        if(userText.getText().length() < 8){
                            errorLabel.setText("*Username is too short!");
                        }
                        else
                        if(!(passwordText.toString().matches(repassText.toString()))){
                            errorLabel.setText("Passwords do not match!");
                        }
                        else
                        if(!isValidEmailAddress(emailAddText.getText())){
                            errorLabel.setText("*Invalid Email!");
                        }
                        else
                        if(!isValidAddress(addText.getText())){
                            errorLabel.setText("*Invalid Address!");
                        }
                    }
                }

            });
            //returns to the previous page
            previous = new JButton("Previous Page");
            previous.addActionListener(new ActionListener(){

                public void actionPerformed(ActionEvent e) {
                    // TODO Auto-generated method stub
                    if(e.getSource() == previous){
                        //card.show(login panel);
                    }
                }

            });
            Box verticalContainer = Box.createVerticalBox();
            Box horizontalContainer = Box.createHorizontalBox();
            Box mergerContainer = Box.createVerticalBox();

            verticalContainer.add(Box.createVerticalStrut(150));
            verticalContainer.add(firstLab);
            verticalContainer.add(firstText);
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(lastLab);
            verticalContainer.add(lastText);
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(userLab);
            verticalContainer.add(userText);
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(passwordLab);
            verticalContainer.add(passwordText);
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(repassLab); 
            verticalContainer.add(repassText);  
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(address); 
            verticalContainer.add(addText);
            verticalContainer.add(Box.createVerticalStrut(5));
            verticalContainer.add(emailAdd);
            verticalContainer.add(emailAddText);    
            verticalContainer.add(Box.createVerticalStrut(5));

            //horizontal
            verticalContainer.add(Box.createVerticalStrut(5));
            horizontalContainer.add(submit);
            horizontalContainer.add(Box.createHorizontalStrut(5));
            horizontalContainer.add(previous);

            //merger
            mergerContainer.add(verticalContainer);
            mergerContainer.add(horizontalContainer);

            add(mergerContainer);
            setVisible(true);
        }

        //regex check for valid Email
    public boolean isValidEmailAddress(String email){
            java.util.regex.Pattern p = java.util.regex.Pattern.compile("[A-Za-z0-9._\\%-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}");
            java.util.regex.Matcher m = p.matcher(email);
            return m.matches();

        }
    //regex check for valid Address
    public boolean isValidAddress(String address){
        java.util.regex.Pattern p = java.util.regex.Pattern.compile("\\d{1,3}.?\\d{0,3}\\s[a-zA-Z]{2,30}\\s[a-zA-Z]{2,15}");
        java.util.regex.Matcher m = p.matcher(address);
        return m.matches();

    }
    }

首页面板类

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

//NO Panel Yet
@SuppressWarnings("serial")
public class homePage extends JPanel{

        JButton uploadEmail, viewEmail;
    public homePage(){
        setSize(700,700);
        uploadEmail = new JButton("Upload Your Email");
        uploadEmail.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == uploadEmail){
                    new loadEmail();
                }
            }

        });
        viewEmail = new JButton("View An Email");
        viewEmail.addActionListener(new ActionListener(){       

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == viewEmail){
                    new emailView();
                }
            }

        });

        add(uploadEmail);
        add(viewEmail);
        setVisible(true);
    }
}

我查看电子邮件面板

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class emailView extends JPanel{
        JPanel viewPanel;
        JButton logout, delete, homepage;
        JTable emailList;

        //Cannot be edited or may be in a new panel
        /*
        JLabel fileLab, toLab, fromLab, subjectLab,topicLab, emailLab, notesLab, attachLab;
        JTextField fileText, toText, fromText, subjectText, topicText;
        JTextArea emailText, notesText, attachText;
        */
    public emailView(){
        setSize(700,700);
        setVisible(true);

        emailList = new JTable();
        logout = new JButton("Logout");
        logout.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == logout){
                    new textEmailLog();
                }
            }

        });
        delete = new JButton("Delete");
        delete.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == delete){

                }
            }

        });
        homepage = new JButton("HomePage");
        homepage.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == homepage){
                    new homePage();
                }

            }

        });
        Box horizontalContainer = Box.createHorizontalBox();
        Box verticalContainer = Box.createVerticalBox();
        Box mergerContainer = Box.createVerticalBox();

        horizontalContainer.add(logout);
        horizontalContainer.add(Box.createHorizontalStrut(5));
        horizontalContainer.add(homepage);
        horizontalContainer.add(Box.createHorizontalStrut(5));
        horizontalContainer.add(delete);
        horizontalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(emailList);
        mergerContainer.add(horizontalContainer);
        mergerContainer.add(verticalContainer);
        add(mergerContainer);

        setVisible(true);
    }
}

我上传的电子邮件面板

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;


public class loadEmail extends JPanel{
        JPanel loadPanel;
        JLabel fileLab, toLab, fromLab, subjectLab, topicLab, emailLab, notesLab, attachLab;
        JTextField fileText, toText, fromText, subjectText, topicText;
        JTextArea emailText, notesText, attachText; //attachment text will be changed
        JButton cancel, complete, enter;//enter may not be necessary
    public loadEmail(){
        setSize(700,700);

        fileLab = new JLabel("Enter a new File: ");
        fileText = new JTextField();
        enter = new JButton("Enter");
        enter.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == enter){
                    //opens file directory window
                }
            }

        });
        toLab = new JLabel("To: ");
        toText = new JTextField();
        toText.setSize(5, 30);
        fromLab = new JLabel("From: ");
        fromText = new JTextField();
        subjectLab = new JLabel("Subject: ");
        subjectText = new JTextField();
        topicLab = new JLabel("Topic: ");
        topicText = new JTextField();
        emailLab = new JLabel("Email Content: ");
        emailText = new JTextArea();
        notesLab = new JLabel("Comments: ");
        notesText = new JTextArea();
        attachLab = new JLabel("Attachments");
        attachText = new JTextArea();
        cancel = new JButton("Cancel");
        cancel.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == cancel){
                    //dispose page
                }
            }

        });
        complete = new JButton("Complete");
        complete.addActionListener(new ActionListener(){

            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                if(e.getSource() == complete){
                    //store in database, prompt user for new email to enter in other wise return to homepage

                }
            }

        });

        Box verticalContainer = Box.createVerticalBox();
        Box horizontalContainer = Box.createHorizontalBox();
        Box mergerContainer = Box.createVerticalBox();

        verticalContainer.add(fileLab);
        verticalContainer.add(fileText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(Box.createHorizontalStrut(50));
        verticalContainer.add(enter);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(toLab);
        verticalContainer.add(toText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(fromLab);
        verticalContainer.add(fromText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(subjectLab);
        verticalContainer.add(subjectText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(topicLab);
        verticalContainer.add(topicText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(emailLab);
        verticalContainer.add(emailText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(notesLab);
        verticalContainer.add(notesText);
        verticalContainer.add(Box.createVerticalStrut(5));
        verticalContainer.add(attachLab);
        verticalContainer.add(attachText);
        verticalContainer.add(Box.createVerticalStrut(5));

        horizontalContainer.add(cancel);
        horizontalContainer.add(Box.createHorizontalStrut(5));
        horizontalContainer.add(complete);

        mergerContainer.add(verticalContainer);
        mergerContainer.add(horizontalContainer);
        add(mergerContainer);
        setVisible(true);

    }

}

Answer 1:

简单的答案是没有。 造成这种情况的原因是你最终不得不父容器和揭露CardLayout所有的子组件，这不仅暴露了你的应用程序的部分潜在的虐待，它紧密结合使其难以导航添加/删除步骤未来...

一个更好的解决办法是制定某种控制器的interface ，它定义了每个视图可以做（例如showHome ， nextView ， previousView ），那么您需要通过这个接口，每个视图的实现。 然后，每个视图将使用该接口来请求作为需要的变化。

该控制器会知道之类的东西，目前来看，主视图，以及如何某些视图（下一首/上）之间移动的要求。

更新了简单的例子 

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.ContainerAdapter;
import java.awt.event.ContainerEvent;
import java.awt.event.HierarchyEvent;
import java.awt.event.HierarchyListener;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class AllYouViewBelongToMe {

    public static void main(String[] args) {
        new AllYouViewBelongToMe();
    }

    public AllYouViewBelongToMe() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public interface ViewContoller {

        public void goHome();

        public void nextView();

        public void previousView();

    }

    public static class DefaultViewController implements ViewContoller {

        public static final String HOME = "home";

        private Component currentView = null;
        private List<Component> views;
        private Map<Component, String> mapNames;

        private Container parent;
        private CardLayout cardLayout;

        public DefaultViewController(Container parent, CardLayout cardLayout) {
            this.parent = parent;
            this.cardLayout = cardLayout;
            views = new ArrayList<>(25);
            mapNames = new HashMap<>(25);
        }

        public CardLayout getCardLayout() {
            return cardLayout;
        }

        public Container getParent() {
            return parent;
        }

        public void addView(Component comp, String name) {
            if (!HOME.equals(name)) {
                views.add(comp);
            }
            mapNames.put(comp, name);
            getParent().add(comp, name);
        }

        public void removeView(Component comp, String name) {
            views.remove(comp);
            mapNames.remove(comp);
            getParent().remove(comp);
        }

        @Override
        public void goHome() {
            currentView = null;
            getCardLayout().show(getParent(), HOME);
        }

        @Override
        public void nextView() {
            if (views.size() > 0) {
                String name = null;
                if (currentView == null) {
                    currentView = views.get(0);
                    name = mapNames.get(currentView);
                } else {
                    int index = views.indexOf(currentView);
                    index++;
                    if (index >= views.size()) {
                        index = 0;
                    }
                    currentView = views.get(index);
                    name = mapNames.get(currentView);
                }
                getCardLayout().show(getParent(), name);
            }
        }

        @Override
        public void previousView() {
            if (views.size() > 0) {
                String name = null;
                if (currentView == null) {
                    currentView = views.get(views.size() - 1);
                    name = mapNames.get(currentView);
                } else {
                    int index = views.indexOf(currentView);
                    index--;
                    if (index < 0) {
                        index = views.size() - 1;
                    }
                    currentView = views.get(index);
                    name = mapNames.get(currentView);
                }
                getCardLayout().show(getParent(), name);
            }
        }

    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new BorderLayout());

            CardLayout cardLayout = new CardLayout();
            JPanel view = new JPanel(cardLayout);

            final DefaultViewController controller = new DefaultViewController(view, cardLayout);
            controller.addView(createPane("home"), DefaultViewController.HOME);
            controller.addView(createPane("Page #1"), "View1");
            controller.addView(createPane("Page #2"), "View2");
            controller.addView(createPane("Page #3"), "View3");
            controller.addView(createPane("Page #4"), "View4");

            controller.goHome();

            JPanel controls = new JPanel();
            JButton btnPrev = new JButton("<");
            JButton btnHome = new JButton("Home");
            JButton btnNext = new JButton(">");

            controls.add(btnPrev);
            controls.add(btnHome);
            controls.add(btnNext);

            btnNext.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    controller.nextView();
                }
            });
            btnPrev.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    controller.previousView();
                }
            });
            btnHome.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    controller.goHome();
                }
            });

            add(view);
            add(controls, BorderLayout.SOUTH);

        }

        protected JPanel createPane(String name) {

            JPanel panel = new JPanel(new GridBagLayout());
            panel.add(new JLabel(name));

            return panel;

        }
    }

}


文章来源: How to effectively use cardlayout in java in order to switch from panel using buttons inside various panel constructors
标签： java swing button user-interface cardlayout
举报

收藏的人(0)

Ta的文章 更多文章
登录 后发表评论
0条评论
还没有人评论过~