Java Swing-如何使下一个和上一个按钮显示数组中对象的变量？

bigranga 发表于 Dev

比格朗加

每个人。我创建了一个自定义类“人类”的数组以创建一个“城市”。
每个人都有一个随机生成的姓名和年龄。
我想使用下一个和上一个按钮滚动查看每个人并查看其信息。
我将如何去做呢？
这是我的源代码：

JamiesCity.java：

package jamiesCity;

import javax.swing.*;

import net.miginfocom.swing.MigLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class JamiesCity {

    public static void main(String[] args) {
        JamiesCity j = new JamiesCity();
        j.createMainGUI();
    }

    City newCity;

    public void createMainGUI(){    
        JFrame startGUI;
        startGUI = new JFrame();
        startGUI.setSize(485, 85);
        startGUI.setLocationRelativeTo(null);
        startGUI.setTitle("Jamie's City");
        startGUI.setLayout(null);
        startGUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        startGUI.setResizable(false);

        JButton create;
        create = new JButton("New City");
        create.setBounds(15, 15, 130, 25);
        startGUI.add(create);

        JTextField title;
        title = new JTextField("City Name");
        title.setBounds(155, 15, 305, 25);
        startGUI.add(title);

        create.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                createCity(title.getText());
            }
        });
        startGUI.setVisible(true);
    }

    public void createCity(String name){
        newCity = new City(name);
        dispCityInfo(name, newCity);        
    }

    public void dispCityInfo(String name, City city){
        JFrame dispCity = new JFrame(name);
        dispCity.setLocationRelativeTo(null);
        dispCity.setResizable(false);
        dispCity.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        JPanel panel = new JPanel();

        panel.setLayout(new MigLayout("insets 30"));

        JLabel personMarker = new JLabel("-------Person-------");
        JLabel cityName = new JLabel("City Name: ");
        JLabel cityPopulation = new JLabel("City Population: ");
        JLabel personName = new JLabel("Name: ");
        JLabel personAge = new JLabel("Age: ");
        JLabel personGender = new JLabel("Gender: ");

        String theName = new String(city.getFirstNameOfPerson(0) + " " + newCity.getLastNameOfPerson(0));
        String theAge = new String(city.getAgeOfPersonAsString(0));
        String theGender = new String(city.getGenderOfPerson(0));

        JLabel theCityName = new JLabel(city.getCityName());
        JLabel theCityPopulation = new JLabel(city.getPopulationAsString());
        JLabel thePersonName = new JLabel(theName);
        JLabel thePersonAge = new JLabel(theAge);
        JLabel thePersonGender = new JLabel(theGender);

        JButton next = new JButton("Next");
        JButton previous = new JButton("Previous");

        //------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

        dispCity.add(panel);
        panel.add(cityName);
        panel.add(theCityName, "wrap");
        panel.add(cityPopulation);
        panel.add(theCityPopulation, "wrap");
        panel.add(personMarker, "span 2, align center, wrap");
        panel.add(personName);
        panel.add(thePersonName, "wrap");
        panel.add(personAge);
        panel.add(thePersonAge, "wrap");
        panel.add(personGender);
        panel.add(thePersonGender, "wrap");
        panel.add(next, "cell 0 6 2 1, width 200");
        panel.add(previous, "cell 0 7 2 1, width 200");

        //------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

        next.addActionListener(new ActionListener() { //show info of next person
            public void actionPerformed(ActionEvent e) {

            }
        });

        previous.addActionListener(new ActionListener() { //show info of previous person
            public void actionPerformed(ActionEvent e) {

            }
        });

        //------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

        dispCity.pack();
        dispCity.setVisible(true);
    }

}

City.java：

package jamiesCity;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class City {

    //Variables

    private String CityName;
    private int population;
    private int popLength;
    public Human[] thePeople;
    private ArrayList<String> maleFirsts = new ArrayList<String>();
    private ArrayList<String> femaleFirsts = new ArrayList<String>();
    private ArrayList<String> lasts = new ArrayList<String>();

    //Constructor

    public City(String cityName){

        this.CityName = cityName;

        Random rand = new Random();
        int randomNum = rand.nextInt((8000000 - 10000) + 1) + 10000;
        this.setPopulation(randomNum);  

        thePeople = new Human[(int) population];

        MaleFirstNames();
        FemaleFirstNames();
        LastNames();

        for(int i = 0; i < thePeople.length; i++){

            String MFirstName = "";
            Random MfirstNames = new Random();
            int MfirstNameRand = MfirstNames.nextInt((maleFirsts.size() - 0) + 0);
            MFirstName = maleFirsts.get(MfirstNameRand);

            String FFirstName = "";
            Random FfirstNames = new Random();
            int FfirstNameRand = FfirstNames.nextInt((maleFirsts.size() - 0) + 0);
            FFirstName = femaleFirsts.get(FfirstNameRand);

            String LastName = "";
            Random LastNameRand = new Random();
            int LastNameRandomNumber = LastNameRand.nextInt((lasts.size() - 0) + 0);
            LastName = lasts.get(LastNameRandomNumber);

            Random AgeRand = new Random();
            int Age = AgeRand.nextInt((101 - 1) + 1);

            if(i < thePeople.length / 2){
                thePeople[i] = new Human(MFirstName, LastName, Age, "Male");
            }
            if(i == thePeople.length / 2){
                thePeople[i] = new Human(FFirstName, LastName, Age, "Female");
            }   
        }
        this.popLength = thePeople.length;
    }

    //Scan CSVs

    private void MaleFirstNames(){
        File maleFirstsCSV = new File("src/jamiesCity/male.firstnames.csv");
        try {
            Scanner maleFirstNames = new Scanner(maleFirstsCSV);
            while(maleFirstNames.hasNext()){
                String input = maleFirstNames.next();
                String values[] = input.split(",");
                maleFirsts.add(values[0]);
            }
            maleFirstNames.close();
        } catch (FileNotFoundException e) {
            System.out.println("Cannot Find Male First Names CSV File");
        }
    }

    private void FemaleFirstNames(){
        File maleFirstsCSV = new File("src/jamiesCity/female.firstnames.csv");
        try {
            Scanner femaleFirstNames = new Scanner(maleFirstsCSV);
            while(femaleFirstNames.hasNext()){
                String input = femaleFirstNames.next();
                String values[] = input.split(",");
                femaleFirsts.add(values[0]);
            }
            femaleFirstNames.close();
        } catch (FileNotFoundException e) {
            System.out.println("Cannot Find Female First Names CSV File");
        }
    }

    private void LastNames(){
        File maleFirstsCSV = new File("src/jamiesCity/CSV_Database_of_Last_Names.csv");
        try {
            Scanner lastNames = new Scanner(maleFirstsCSV);
            while(lastNames.hasNext()){
                String input = lastNames.next();
                String values[] = input.split(",");
                lasts.add(values[0]);
            }
            lastNames.close();
        } catch (FileNotFoundException e) {
            System.out.println("Cannot Find Last Names CSV File");
        }
    }

    //Getters and Setters

    public String getFirstNameOfPerson(int HumanCount){
        String name = thePeople[HumanCount].getFirstName();
        return name;
    }
    public String getGenderOfPerson(int HumanCount){
        String gender = thePeople[HumanCount].getGender();
        return gender;
    }
    public String getLastNameOfPerson(int HumanCount){
        String name = thePeople[HumanCount].getLastName();
        return name;
    }
    public int getAgeOfPerson(int HumanCount){
        int age = thePeople[HumanCount].getAge();
        return age;
    }

    public String getAgeOfPersonAsString(int HumanCount){
        StringBuilder age = new StringBuilder();
        age.append(thePeople[HumanCount].getAge());
        String theAge = age.toString();
        return theAge;
    }

    public int getPopLength() {
        return popLength;
    }

    public void setPopLength(int i){
        this.popLength = i;
    }

    public int getPopulation() {
        return population;
    }

    public String getPopulationAsString() {
        StringBuilder builder = new StringBuilder();
        builder.append(population);
        String pop = builder.toString();
        return pop;
    }

    public void setPopulation(int population) {
        this.population = population;
    }

    public String getCityName() {
        return CityName;
    }

    public void setCityName(String cityName) {
        CityName = cityName;
    }

    //End of Getters and Setters
}

Human.java：

package jamiesCity;

public class Human {

    private String firstName = "firstName";
    private String lastName = "lastName";
    private int Age = 99;
    private String gender = null;

    public int getAge(){
        return Age;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public void setAge(int age){
        Age = age;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Human(String firstName, String lastName, int Age, String gender){
        this.firstName = firstName;
        this.lastName = lastName;
        this.Age = Age;
        this.gender = gender;
    }

}

任何帮助将非常感激。谢谢：）

充满鳗鱼的气垫船

意见建议：

由于这似乎是一项任务，因此我将避免为您提供代码，而是提供一些一般性的建议，希望它们可以帮助您入门。
为容纳您的Humans的任何数组或集合创建一个int索引变量-此处看起来是thePeople数组。将此索引设置为非静态字段。
在下一个按钮的ActionListener中，推进索引，确保其大小不等于或大于数组或集合，获取该索引的Human，并将其显示在GUI中。
相反，在上一个按钮中，递减索引，确保索引为0或更大，然后获取该索引的Human，然后将其显示在GUI中。
您将要确定如果索引到达边界时该怎么做-变得小于0或等于数组的长度。如果要循环搜索，则如果搜索结果小于零，length - 1则将其分配给，或者将其分配给长度大小，然后将其分配给0。

不相关的建议：

避免使用空布局。空布局和setBounds()Swing新手似乎是创建复杂GUI的最简单，最好的方法，但您创建的Swing GUI越多，使用它们时就会遇到更大的困难。当GUI调整大小时，它们不会重新调整组件的大小；它们是要增强或维护的皇家女巫；放置在滚动窗格中时，它们会完全失败；在所有平台或与原始分辨率不同的屏幕分辨率下，它们看起来都令人作呕。
您将要学习和使用Java命名约定。变量名都应以小写字母开头，而类名应以大写字母开头。学习和遵循此规则将使我们能够更好地理解您的代码，并使您能够更好地理解其他人的代码。

好吧，我撒谎并确实创造了一些东西来测试概念：

import javax.swing.*;
import javax.swing.text.JTextComponent;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.util.ArrayList;
import java.util.List;

@SuppressWarnings("serial")
public class SimpleCityGui extends JPanel {
    private SimpleCity city = new SimpleCity();
    private SimpleHumanPanel humanPanel = new SimpleHumanPanel();

    public SimpleCityGui() {
        humanPanel.setFocusable(false);
        humanPanel.setBorder(BorderFactory.createTitledBorder("Current Human"));

        JPanel btnPanel = new JPanel();
        btnPanel.add(new JButton(new AddHumanAction("Add")));
        btnPanel.add(new JButton(new NextAction("Next")));
        btnPanel.add(new JButton(new PreviousAction("Previous")));

        setLayout(new BorderLayout());
        add(humanPanel, BorderLayout.CENTER);
        add(btnPanel, BorderLayout.PAGE_END);
    }

    private class AddHumanAction extends AbstractAction {
        SimpleHumanPanel innerHumanPanel = new SimpleHumanPanel();

        public AddHumanAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(0);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            innerHumanPanel.clear();
            Component parentComponent = SimpleCityGui.this;
            SimpleHumanPanel message = innerHumanPanel;
            String title = "Create a Human";
            int optionType = JOptionPane.OK_CANCEL_OPTION;
            int messageType = JOptionPane.PLAIN_MESSAGE;
            int selection = JOptionPane.showConfirmDialog(parentComponent,
                    message, title, optionType, messageType);

            if (selection == JOptionPane.OK_OPTION) {
                city.addHuman(innerHumanPanel.createHuman());
                humanPanel.setHuman(city.getCurrentHuman());
            }
        }
    }

    private class NextAction extends AbstractAction {

        public NextAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(0);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            SimpleHuman nextHuman = city.next();
            if (nextHuman != null) {
                humanPanel.setHuman(nextHuman);
            }
        }
    }

    private class PreviousAction extends AbstractAction {

        public PreviousAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(0);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            SimpleHuman previousHuman = city.previous();
            if (previousHuman != null) {
                humanPanel.setHuman(previousHuman);
            }
        }
    }

    private static void createAndShowGui() {
        SimpleCityGui mainPanel = new SimpleCityGui();

        JFrame frame = new JFrame("SimpleCityGui");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}

@SuppressWarnings("serial")
class SimpleHumanPanel extends JPanel {
    private static final int COLS = 10;
    private static final Insets INSETS = new Insets(5, 5, 5, 5);
    private JTextField firstNameField = new JTextField(COLS);
    private JTextField lastNameField = new JTextField(COLS);
    private JTextComponent[] textComponents = { firstNameField, lastNameField };
    private SimpleHuman human;

    public SimpleHumanPanel() {
        setLayout(new GridBagLayout());
        add(new JLabel("First Name:"), createGbc(0, 0));
        add(firstNameField, createGbc(1, 0));
        add(new JLabel("Last Name:"), createGbc(0, 1));
        add(lastNameField, createGbc(1, 1));
    }

    @Override
    public void setFocusable(boolean focusable) {
        super.setFocusable(focusable);
        for (JTextComponent jTextComponent : textComponents) {
            jTextComponent.setFocusable(focusable);
        }
    }

    public void setHuman(SimpleHuman human) {
        this.human = human;
        firstNameField.setText(human.getFirstName());
        lastNameField.setText(human.getLastName());
    }

    public SimpleHuman getHuman() {
        return human;
    }

    public void clear() {
        this.human = null;
        for (JTextComponent jTextComponent : textComponents) {
            jTextComponent.setText("");
        }
    }

    public SimpleHuman createHuman() {
        String firstName = firstNameField.getText();
        String lastName = lastNameField.getText();
        human = new SimpleHuman(firstName, lastName);
        return human;
    }

    private static GridBagConstraints createGbc(int x, int y) {
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = x;
        gbc.gridy = y;
        gbc.insets = INSETS;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        return gbc;
    }
}

class SimpleCity {
    private List<SimpleHuman> humanList = new ArrayList<>();
    private int humanListIndex = -1; // start with a nonsense value

    public void addHuman(SimpleHuman h) {
        humanList.add(h);
        if (humanListIndex == -1) {
            humanListIndex = 0;
        }
    }

    public SimpleHuman getHuman(int index) {
        return humanList.get(index);
    }

    public SimpleHuman getCurrentHuman() {
        if (humanListIndex == -1) {
            return null;
        }
        return humanList.get(humanListIndex);

    }

    public SimpleHuman next() {
        if (humanListIndex == -1) {
            return null;
        }

        humanListIndex++;
        humanListIndex %= humanList.size(); // set back to 0 if == size
        return humanList.get(humanListIndex);
    }

    public SimpleHuman previous() {
        if (humanListIndex == -1) {
            return null;
        }

        humanListIndex--;
        humanListIndex += humanList.size();
        humanListIndex %= humanList.size();
        return humanList.get(humanListIndex);
    }
}

class SimpleHuman {
    private String firstName;
    private String lastName;

    public SimpleHuman(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result
                + ((firstName == null) ? 0 : firstName.hashCode());
        result = prime * result
                + ((lastName == null) ? 0 : lastName.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        SimpleHuman other = (SimpleHuman) obj;
        if (firstName == null) {
            if (other.firstName != null)
                return false;
        } else if (!firstName.equals(other.firstName))
            return false;
        if (lastName == null) {
            if (other.lastName != null)
                return false;
        } else if (!lastName.equals(other.lastName))
            return false;
        return true;
    }

    @Override
    public String toString() {
        return "SimpleHuman [firstName=" + firstName + ", lastName=" + lastName
                + "]";
    }

}