显示来自高级for循环的文本字段中的数据

Question

A如下面的代码所示，当按钮被按下时，我想要将数据输入到textfield中，此时我要将其打印为控制台，如何添加到textfield？是text.add吗？

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
import java.util.ArrayList;
import javax.swing.*;


public class displayGui extends JFrame implements WindowListener, ActionListener {

    JButton showData;

    JButton hideData;

    private static final int FRAME_WIDTH = 100;
    private static final int FRAME_HEIGHT = 100;
    JTextField text = new JTextField(20);
    ArrayList<Phone> phones = new ArrayList<>();
    public displayGui() {

        phones.add(new Phone("Sony", "Experia X", 32, 12.5 , 4.6 , "Yes" , 150));
        phones.add(new Phone("Sony", "Experia Y", 64, 14.2 , 5.6 , "Yes" , 175));
        phones.add(new Phone("Samsung", "Galaxy M", 64, 14.5 , 5.4 , "Yes" , 180));
        phones.add(new Phone("Nokia", "3330", 16, 13.2 , 2.3 , "No" , 90));
        phones.add(new Phone("Motorola", "M1", 8, 11.3 , 4.9 , "Yes" , 100));
        phones.add(new Phone("Iphone", "6", 32, 13.5 , 6.4 , "Yes" , 250));
        phones.add(new Phone("Alcatel", "A3", 8, 9.3 , 2.4 , "No" , 50));
        JFrame frame = new JFrame();
        JPanel panel = new JPanel();

        addWindowListener(this);
        showData = new JButton("Show Data");
        add(showData);
        panel.add(text);
        showData.addActionListener(this);


        panel.add(showData);
        hideData = new JButton("Hide Data");
        panel.add(hideData);
        hideData.addActionListener(this);
        frame.add(panel);

        frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
    @Override

    public void actionPerformed(ActionEvent e) {
        if(e.getSource().equals(showData)) {
            if (showData.isSelected()){

                for (Phone phone : phones){
                    System.out.println("Phone Make: " + phone.getMake());
                    System.out.println("Phone Model: " + phone.getModel());
                    System.out.println("Phone Memory: " + phone.getMemory());
                    System.out.println("Phone Camera: " + phone.getCamera());
                    System.out.println("Phone screen-size: " + phone.getScreensize());
                    System.out.println("Is the phone a smart phone: " + phone.getSmart());
                    System.out.println("The phone costs: " + phone.getPrice());
                };

            }
        }



        for (Phone phone : phones){
            System.out.println("Phone Make: " + phone.getMake());
            System.out.println("Phone Model: " + phone.getModel());
            System.out.println("Phone Memory: " + phone.getMemory());
            System.out.println("Phone Camera: " + phone.getCamera());
            System.out.println("Phone screen-size: " + phone.getScreensize());
            System.out.println("Is the phone a smart phone: " + phone.getSmart());
            System.out.println("The phone costs: " + phone.getPrice());
        }

        text.setText("Testing");

    }

    @Override
    public void windowOpened(WindowEvent e) {

    }

    @Override
    public void windowClosing(WindowEvent e) {
        dispose();
        System.exit(0);
    }

    @Override
    public void windowClosed(WindowEvent e) {

    }

    @Override
    public void windowIconified(WindowEvent e) {

    }

    @Override
    public void windowDeiconified(WindowEvent e) {

    }

    @Override
    public void windowActivated(WindowEvent e) {

    }

    @Override
    public void windowDeactivated(WindowEvent e) {

    }
}

import java.io.*;
import java.util.ArrayList;

public class Tester {
    public static void main(String[] args) throws IOException, ClassNotFoundException {

        ArrayList<Phone> phones = new ArrayList<>();
        phones.add(new Phone("Sony", "Experia X", 32, 12.5 , 4.6 , "Yes" , 150));
        phones.add(new Phone("Sony", "Experia Y", 64, 14.2 , 5.6 , "Yes" , 175));
        phones.add(new Phone("Samsung", "Galaxy M", 64, 14.5 , 5.4 , "Yes" , 180));
        phones.add(new Phone("Nokia", "3330", 16, 13.2 , 2.3 , "No" , 90));
        phones.add(new Phone("Motorola", "M1", 8, 11.3 , 4.9 , "Yes" , 100));
        phones.add(new Phone("Iphone", "6", 32, 13.5 , 6.4 , "Yes" , 250));
        phones.add(new Phone("Alcatel", "A3", 8, 9.3 , 2.4 , "No" , 50));

        try {
            System.out.println("Check to see if file exists");
            FileInputStream fileIn = new FileInputStream("phone.ser");
            System.out.println("It exists");
            ObjectInputStream objectIn = new ObjectInputStream(fileIn);
            System.out.println("Reading now");


            phones = (ArrayList<Phone>) objectIn.readObject();
            for (Phone phone : phones){
                System.out.println("Phone Make: " + phone.getMake());
                System.out.println("Phone Model: " + phone.getModel());
                System.out.println("Phone Memory: " + phone.getMemory());
                System.out.println("Phone Camera: " + phone.getCamera());
                System.out.println("Phone screen-size: " + phone.getScreensize());
                System.out.println("Is the phone a smart phone: " + phone.getSmart());
                System.out.println("The phone costs: " + phone.getPrice());
            }

            objectIn.close();
            } catch (FileNotFoundException e1) {
            System.out.println("file does not exist");

            try {
                System.out.println("Creating it now ....");
                FileOutputStream fileOut = new FileOutputStream("phone.ser");

                ObjectOutputStream objectOut = new ObjectOutputStream(fileOut);

                objectOut.writeObject(phones);

                objectOut.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            ///deserialization///
            try {
                FileInputStream fileIn = new FileInputStream("phone.ser");

                ObjectInputStream objectIn = new ObjectInputStream(fileIn);
                Phone newPhone = (Phone) objectIn.readObject();

                objectIn.close();
                System.out.println("Phone Make: " + newPhone.getMake());
                System.out.println("Phone Model: " + newPhone.getModel());
                System.out.println("Phone Memory: " + newPhone.getMemory());
                System.out.println("Phone Camera: " + newPhone.getCamera());
                System.out.println("Phone screen-size: " + newPhone.getScreensize());
                System.out.println("Is the phone a smart phone: " + newPhone.getSmart());
                System.out.println("The phone costs: " + newPhone.getPrice());
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.io.*;
import java.util.ArrayList;

public class MainSer {
    public static void main(String[] args) throws IOException, ClassNotFoundException {
        new displayGui();

        ArrayList<Phone> phones = new ArrayList<>();
        phones.add(new Phone("Sony", "Experia X", 32, 12.5 , 4.6 , "Yes" , 150));
        phones.add(new Phone("Sony", "Experia Y", 64, 14.2 , 5.6 , "Yes" , 175));
        phones.add(new Phone("Samsung", "Galaxy M", 64, 14.5 , 5.4 , "Yes" , 180));
        phones.add(new Phone("Nokia", "3330", 16, 13.2 , 2.3 , "No" , 90));
        phones.add(new Phone("Motorola", "M1", 8, 11.3 , 4.9 , "Yes" , 100));
        phones.add(new Phone("Iphone", "6", 32, 13.5 , 6.4 , "Yes" , 250));
        phones.add(new Phone("Alcatel", "A3", 8, 9.3 , 2.4 , "No" , 50));



        //serialization//
        try {
            FileOutputStream fileOut = new FileOutputStream("phone.ser");
            ObjectOutputStream Out = new ObjectOutputStream(fileOut);
            Out.writeObject(phones);
            Out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        ////deserialization///
        try {
            FileInputStream fileIn = new FileInputStream("phone.ser");

            ObjectInputStream objectIn = new ObjectInputStream(fileIn);

            phones = (ArrayList<Phone>) objectIn.readObject();
            for (Phone phone : phones){
                System.out.println("Phone Make: " + phone.getMake());
                System.out.println("Phone Model: " + phone.getModel());
                System.out.println("Phone Memory: " + phone.getMemory());
                System.out.println("Phone Camera: " + phone.getCamera());
                System.out.println("Phone screen-size: " + phone.getScreensize());
                System.out.println("Is the phone a smart phone: " + phone.getSmart());
                System.out.println("The phone costs: " + phone.getPrice());
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        }
    }

import java.io.Serializable;

public class Phone implements Serializable {
    private String make;
    private String model;
    private double memory;
    private double camera;
    private double screensize;
    private String smart;
    private int price;

    public Phone(String make , String model , double memory , double camera, double screensize, String smart , int price){
        this.make = make;
        this.model = model;
        this.memory = memory;
        this.camera = camera;
        this.screensize = screensize;
        this.smart = smart;
        this.price = price;

    }

    public String getMake() {
        return make;
    }

    public String getModel() {
        return model;
    }

    public double getMemory() {
        return memory;
    }

    public double getCamera() {
        return camera;
    }

    public double getScreensize() {
        return screensize;
    }

    public String getSmart() {
        return smart;
    }

    public int getPrice() {
        return price;
    }
}

当我运行它时，我现在让它在控制台上运行。但需要输入到文本字段中。谢谢

Answer 1

在我看来，你看过一本旧的Swing教程。Swing应用程序不需要扩展类JFrame，也不需要实现WindowListener。

我建议您在JTable中而不是在文本字段中显示数据。

您的Phone类可以是记录。

import java.io.Serializable;

public record Phone(String make,
                    String model,
                    double memory,
                    double camera,
                    double screensize,
                    String smart,
                    int price) implements Serializable {

    public static int getFieldCount() {
        return 7;
    }
}

GUI代码中使用了fieldCount方法。(见下文)

我使用一个自定义表模型来显示Phone对象的列表。

从Java 8开始，我更喜欢使用ActionListener实现方法参考。

我创建了两个表model_s -一个空的和一个非空的。单击_Show数据按钮时，我设置非空模型，单击隐藏数据按钮时设置空模型。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.util.Arrays;
import java.util.List;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;

public class DisplayGui {
    private PhoneModel emptyModel;
    private PhoneModel model;
    private JTable table;

    private void buildAndDisplayGui() {
        JFrame frame = new JFrame("Phones");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(createTable(), BorderLayout.CENTER);
        frame.add(createButtons(), BorderLayout.PAGE_END);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private JPanel createButtons() {
        JPanel panel = new JPanel();
        JButton showData = new JButton("Show Data");
        showData.addActionListener(this::showData);
        panel.add(showData);
        JButton hideData = new JButton("Hide Data");
        hideData.addActionListener(this::hideData);
        panel.add(hideData);
        return panel;
    }

    private void createModel() {
        model = new PhoneModel(new Phone("Sony", "Experia X", 32, 12.5 , 4.6 , "Yes" , 150),
                               new Phone("Sony", "Experia Y", 64, 14.2 , 5.6 , "Yes" , 175),
                               new Phone("Samsung", "Galaxy M", 64, 14.5 , 5.4 , "Yes" , 180),
                               new Phone("Nokia", "3330", 16, 13.2 , 2.3 , "No" , 90),
                               new Phone("Motorola", "M1", 8, 11.3 , 4.9 , "Yes" , 100),
                               new Phone("Iphone", "6", 32, 13.5 , 6.4 , "Yes" , 250),
                               new Phone("Alcatel", "A3", 8, 9.3 , 2.4 , "No" , 50));
    }

    private JScrollPane createTable() {
        createModel();
        emptyModel = new PhoneModel();
        table = new JTable(emptyModel);
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        JScrollPane scrollPane = new JScrollPane(table);
        return scrollPane;
    }

    private void hideData(ActionEvent event) {
        table.setModel(emptyModel);
    }

    private void showData(ActionEvent event) {
        table.setModel(model);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(() -> new DisplayGui().buildAndDisplayGui());
    }
}

class PhoneModel extends AbstractTableModel {
    private List<Phone> phones;

    public PhoneModel(Phone... phones) {
        this(Arrays.asList(phones));
    }

    public PhoneModel(List<Phone> phones) {
        this.phones = phones;
    }

    @Override
    public Class<?> getColumnClass(int columnIndex) {
        Class<?> theClass;
        switch (columnIndex) {
            case 0:
            case 1:
            case 5:
                theClass = String.class;
                break;
            case 2:
            case 3:
            case 4:
                theClass = Double.class;
                break;
            case 6:
                theClass = Integer.class;
                break;
            default:
                throw new ArrayIndexOutOfBoundsException(columnIndex);
        }
        return theClass;
    }

    @Override
    public int getColumnCount() {
        return Phone.getFieldCount();
    }

    @Override
    public String getColumnName(int column) {
        String name;
        switch (column) {
            case 0:
                name = "Make";
                break;
            case 1:
                name = "Model";
                break;
            case 2:
                name = "Memory";
                break;
            case 3:
                name = "Camera";
                break;
            case 4:
                name = "Screen Size";
                break;
            case 5:
                name = "Smart";
                break;
            case 6:
                name = "Price";
                break;
            default:
                throw new ArrayIndexOutOfBoundsException(column);
        }
        return name;
    }

    @Override
    public int getRowCount() {
        return phones == null ? 0 : phones.size();
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        Phone phone = phones.get(rowIndex);
        Object val;
        switch (columnIndex) {
            case 0:
                val = phone.make();
                break;
            case 1:
                val = phone.model();
                break;
            case 2:
                val = Double.valueOf(phone.memory());
                break;
            case 3:
                val = Double.valueOf(phone.camera());
                break;
            case 4:
                val = Double.valueOf(phone.screensize());
                break;
            case 5:
                val = phone.smart();
                break;
            case 6:
                val = Integer.valueOf(phone.price());
                break;
            default:
                throw new ArrayIndexOutOfBoundsException(columnIndex);
        }
        return val;
    }
}

隐藏的数据如下所示：

(这是最初的显示，因为我最初设置了空表模型。)

​

​

所显示的数据：

​

​