Java 如何将组合框的选定项设置为其他值？

我当前正在尝试将组合框中的选定项设置为其他值。在本例中，我使用的是鞋码，我想选择鞋码，在选择鞋码并点击开始按钮后，我想让它读取尺码代码

这就是我努力实现的目标：

这就是我所拥有的：

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ComboBoxDemo extends JFrame implements ActionListener{
  //declarations
  JButton btnPay = new JButton("Start");

  /*ShoeSizeArray 
  String[] comboLabels = {"5", "5.5","6", "6.5", "7", "7.5", "8", "8.5", "9", "9.5", "10", "10.5", "11", "11.5", 
  "12.5", "13.5", "14", "14.5", "15.5", "16"};*/

  //Sizecode Array
  String[] comboLabels = {"560", "570", "580", "590", "600", "610", "620", "630", "640", "650", "660", "670", "680", "690", "700", "710",
    "720", "730", "740", "750", "760", "770"};
  JComboBox <String> combo = new JComboBox<String>(comboLabels);
  JTextArea display = new JTextArea(5,20); 

  //constructor
  public ComboBoxDemo(){
    super("Combo box");
    //panel for button and combobox
    JPanel buttonPanel = new JPanel();
    //add panel to frame
    add(buttonPanel, BorderLayout.SOUTH);
    //add button and combobox to panel
    buttonPanel.add(btnPay);
    buttonPanel.add(combo);
    //register button with ActionListener
    btnPay.addActionListener(this);
    //add text area to center of frame
    add(display, BorderLayout.CENTER);
  }
  public void actionPerformed(ActionEvent e){
    String sizecode = (String)combo.getSelectedItem();
    display.append("\nYou selected the sizecode " + sizecode);
  }

  public static void main(String[] args){
    JFrame fr = new ComboBoxDemo();
    fr.setLocationRelativeTo(null);
    fr.setSize(200,200);
    fr.setVisible(true);
  }
}

import javax.swing.*；
导入java.awt.*；
导入java.awt.event.*；
公共类ComboBoxDemo扩展JFrame实现ActionListener{
//声明
JButton btnPay=新JButton（“开始”）；
/*鞋底阵列
字符串[]组合标签={“5”、“5.5”、“6”、“6.5”、“7”、“7.5”、“8”、“8.5”、“9”、“9.5”、“10”、“10.5”、“11”、“11.5”，
"12.5", "13.5", "14", "14.5", "15.5", "16"};*/
//尺寸码阵列
字符串[]组合标签={“560”、“570”、“580”、“590”、“600”、“610”、“620”、“630”、“640”、“650”、“660”、“670”、“680”、“690”、“700”、“710”，
"720", "730", "740", "750", "760", "770"};
JComboBox组合=新的JComboBox（组合标签）；
JTextArea显示=新的JTextArea（5,20）；
//建造师
公共ComboxDemo（）{
超级（“组合框”）；
//按钮和组合框的面板
JPanel buttonPanel=新的JPanel（）；
//将面板添加到框架
添加（按钮面板，边界布局。南部）；
//将按钮和组合框添加到面板
按钮面板添加（btnPay）；
按钮面板添加（组合）；
//使用ActionListener注册按钮
btnPay.addActionListener（此）；
//将文本区域添加到框架的中心
添加（显示、边框布局、中心）；
}
已执行的公共无效操作（操作事件e）{
字符串大小代码=（字符串）组合。getSelectedItem（）；
display.append（“\n您选择了sizecode”+sizecode）；
}
公共静态void main（字符串[]args）{
JFrame fr=新ComboBoxDemo（）；
fr.setLocationRelativeTo（空）；
fr.setSize（200200）；
fr.setVisible（真）；
}
}

创建一个Shoesize类并根据选择设置标签

下面的代码应该对您有所帮助

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

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

public class ComboBoxDemo extends JFrame implements ActionListener {
    // declarations
    JButton btnPay = new JButton("Start");

    // ShoeSizeArray
    String[] sizes = { "5", "5.5", "6", "6.5", "7", "7.5", "8", "8.5", "9", "9.5", "10", "10.5", "11", "11.5", "12.5",
            "13.5", "14", "14.5", "15.5", "16" };

    // Sizecode Array
    String[] comboLabels = { "560", "570", "580", "590", "600", "610", "620", "630", "640", "650", "660", "670", "680",
            "690", "700", "710", "720", "730", "740", "750", "760", "770" };
    JComboBox<Shoesize> combo = new JComboBox<Shoesize>();
    JTextArea display = new JTextArea(5, 20);

    // constructor
    public ComboBoxDemo() {
        super("Combo box");
        // panel for button and combobox
        JPanel buttonPanel = new JPanel();
        // add panel to frame
        add(buttonPanel, BorderLayout.SOUTH);
        for (int i = 0; i < sizes.length; i++) {
            Shoesize size = new Shoesize(Double.parseDouble(sizes[i]), comboLabels[i]);
            combo.addItem(size);
        }
        // add button and combobox to panel
        buttonPanel.add(btnPay);
        buttonPanel.add(combo);
        // register button with ActionListener
        btnPay.addActionListener(this);
        // add text area to center of frame
        add(display, BorderLayout.CENTER);
    }

    public void actionPerformed(ActionEvent e) {
        Shoesize sizecode = (Shoesize) combo.getSelectedItem();
        display.append("\nYou selected the sizecode " + sizecode.label);
    }

    public static void main(String[] args) {
        JFrame fr = new ComboBoxDemo();
        fr.setLocationRelativeTo(null);
        fr.setSize(200, 200);
        fr.setVisible(true);
    }

    class Shoesize {
        double size;
        String label;

        public Shoesize(double size, String label) {
            super();
            this.size = size;
            this.label = label;
        }

        @Override
        public int hashCode() {
            final int prime = 31;
            int result = 1;
            result = prime * result + getOuterType().hashCode();
            long temp;
            temp = Double.doubleToLongBits(size);
            result = prime * result + (int) (temp ^ (temp >>> 32));
            return result;
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj)
                return true;
            if (obj == null)
                return false;
            if (getClass() != obj.getClass())
                return false;
            Shoesize other = (Shoesize) obj;
            if (!getOuterType().equals(other.getOuterType()))
                return false;
            if (Double.doubleToLongBits(size) != Double.doubleToLongBits(other.size))
                return false;
            return true;
        }

        private ComboBoxDemo getOuterType() {
            return ComboBoxDemo.this;
        }

        @Override
        public String toString() {
            return String.valueOf(size);
        }

    }
}

导入java.awt.BorderLayout；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入javax.swing.JButton；
导入javax.swing.JComboBox；
导入javax.swing.JFrame；
导入javax.swing.JPanel；
导入javax.swing.JTextArea；
公共类ComboBoxDemo扩展JFrame实现ActionListener{
//声明
JButton btnPay=新JButton（“开始”）；
//鞋底阵列
字符串[]大小={“5”、“5.5”、“6”、“6.5”、“7”、“7.5”、“8”、“8.5”、“9”、“9.5”、“10”、“10.5”、“11”、“11.5”、“12.5”，
"13.5", "14", "14.5", "15.5", "16" };
//尺寸码阵列
字符串[]组合标签={“560”、“570”、“580”、“590”、“600”、“610”、“620”、“630”、“640”、“650”、“660”、“670”、“680”，
"690", "700", "710", "720", "730", "740", "750", "760", "770" };
JComboBox组合=新的JComboBox（）；
JTextArea显示=新的JTextArea（5,20）；
//建造师
公共ComboxDemo（）{
超级（“组合框”）；
//按钮和组合框的面板
JPanel buttonPanel=新的JPanel（）；
//将面板添加到框架
添加（按钮面板，边界布局。南部）；
对于（int i=0；i>>32））；
返回结果；
}
@凌驾
公共布尔等于（对象obj）{
if（this==obj）
返回true；
if（obj==null）
返回false；
如果（getClass（）！=obj.getClass（））
返回false；
Shoesize-other=（Shoesize）obj；
如果（！getOuterType（）.equals（other.getOuterType（）））
返回false；
if（Double.doubleToLongBits（大小）！=Double.doubleToLongBits（其他大小））
返回false；
返回true；
}
私有ComboBoxDemo getOuterType（）{
返回ComboBoxDemo.this；
}
@凌驾
公共字符串toString（）{
返回字符串.valueOf（大小）；
}
}
}

创建一个Shoesize类并根据选择设置标签

下面的代码应该对您有所帮助

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

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

public class ComboBoxDemo extends JFrame implements ActionListener {
    // declarations
    JButton btnPay = new JButton("Start");

    // ShoeSizeArray
    String[] sizes = { "5", "5.5", "6", "6.5", "7", "7.5", "8", "8.5", "9", "9.5", "10", "10.5", "11", "11.5", "12.5",
            "13.5", "14", "14.5", "15.5", "16" };

    // Sizecode Array
    String[] comboLabels = { "560", "570", "580", "590", "600", "610", "620", "630", "640", "650", "660", "670", "680",
            "690", "700", "710", "720", "730", "740", "750", "760", "770" };
    JComboBox<Shoesize> combo = new JComboBox<Shoesize>();
    JTextArea display = new JTextArea(5, 20);

    // constructor
    public ComboBoxDemo() {
        super("Combo box");
        // panel for button and combobox
        JPanel buttonPanel = new JPanel();
        // add panel to frame
        add(buttonPanel, BorderLayout.SOUTH);
        for (int i = 0; i < sizes.length; i++) {
            Shoesize size = new Shoesize(Double.parseDouble(sizes[i]), comboLabels[i]);
            combo.addItem(size);
        }
        // add button and combobox to panel
        buttonPanel.add(btnPay);
        buttonPanel.add(combo);
        // register button with ActionListener
        btnPay.addActionListener(this);
        // add text area to center of frame
        add(display, BorderLayout.CENTER);
    }

    public void actionPerformed(ActionEvent e) {
        Shoesize sizecode = (Shoesize) combo.getSelectedItem();
        display.append("\nYou selected the sizecode " + sizecode.label);
    }

    public static void main(String[] args) {
        JFrame fr = new ComboBoxDemo();
        fr.setLocationRelativeTo(null);
        fr.setSize(200, 200);
        fr.setVisible(true);
    }

    class Shoesize {
        double size;
        String label;

        public Shoesize(double size, String label) {
            super();
            this.size = size;
            this.label = label;
        }

        @Override
        public int hashCode() {
            final int prime = 31;
            int result = 1;
            result = prime * result + getOuterType().hashCode();
            long temp;
            temp = Double.doubleToLongBits(size);
            result = prime * result + (int) (temp ^ (temp >>> 32));
            return result;
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj)
                return true;
            if (obj == null)
                return false;
            if (getClass() != obj.getClass())
                return false;
            Shoesize other = (Shoesize) obj;
            if (!getOuterType().equals(other.getOuterType()))
                return false;
            if (Double.doubleToLongBits(size) != Double.doubleToLongBits(other.size))
                return false;
            return true;
        }

        private ComboBoxDemo getOuterType() {
            return ComboBoxDemo.this;
        }

        @Override
        public String toString() {
            return String.valueOf(size);
        }

    }
}

导入java.awt.BorderLayout；
导入java.awt.event.ActionEvent；
导入java.awt.event.ActionListener；
导入javax.swing.JButton；
导入javax.swing.JComboBox；
导入javax.swing.JFrame；
导入javax.swing.JPanel；
导入javax.swing.JTextArea；
公共类ComboBoxDemo扩展JFrame实现ActionListener{
//声明
JButton btnPay=新JButton（“开始”）；
//鞋底阵列
字符串[]大小={“5”、“5.5”、“6”、“6.5”、“7”、“7.5”、“8”、“8.5”、“9”、“9.5”、“10”、“10.5”、“11”、“11.5”、“12.5”，
"13.5", "14", "14.5", "15.5", "16" };
//尺寸码阵列
字符串[]组合
class FooRenderer extends BasicComboBoxRenderer
{
    public Component getListCellRendererComponent(
        JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
    {
        super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);

        if (value instanceof Foo)
        {
            Foo foo = (Foo)value;
            setText( foo.getSize() );
        }

        return this;
    }
}