当从 JComboBox 中选择项目时，如何让 JLabel 显示数组中的值

Question

我正在尝试创建一个算命先生，让你从一个JCombobox中选择一个颜色，然后让你根据你选择的颜色从另一个JCombobox中选择一个数字。例如，如果我选择"红色"或"黄色"，则会显示这组#-{1,3,4,7}。但是，如果我选择"蓝色"或"绿色"，则会显示这组#-{2,6,8,5}。一旦选择一个数字，那么我想在屏幕底部的状态栏（JLabel）上显示与该数字绑定的"财富数组"中的财富。这是我到目前为止的代码：-

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Example2 extends JFrame implements ItemListener {

    private JComboBox maincombobox;
    private JComboBox subcombobox;
    private JLabel labels;
    public Example2(){
        String[] items = {"Select a Color","Red","Blue","Yellow","Green"};
        maincombobox =  new JComboBox(items);
        maincombobox.addItemListener(this);
        getContentPane().add(maincombobox);
        subcombobox = new JComboBox();
        subcombobox.addItemListener(this);      
        subcombobox.setEnabled(true);
        subcombobox.setPrototypeDisplayValue("XXXXXXXXXXXXX");
        getContentPane().add(subcombobox,BorderLayout.EAST);
        labels =  new JLabel("Default");
        getContentPane().add(labels, BorderLayout.SOUTH);

             }
    public void itemStateChanged(ItemEvent e) {
        String[] subitems1 = {"Choose a number","1","3","4","7"};
        String[] subitems2= {"Choose a number","2","6","8","5"};
        String[] fortune = {"Today is you lucky day", "You will get strange looks from people", "Don't touch your left foot today", 
                "You will forget a crucial thing today", "You will meet a mysterious person", "Will win a million dollars", 
                "Good day in the financial market", "Get a life","Think hard, you will find the answer"};

        if (e.getSource() == maincombobox) {
            if (maincombobox.getSelectedItem().equals("Select a Color")) {
               subcombobox.setEnabled(false);
            }    
            else if (maincombobox.getSelectedItem().equals("Red") ||
                maincombobox.getSelectedItem().equals("Yellow") ){
                subcombobox.setEnabled(true);
                subcombobox.removeAllItems();
                for (int i = 0; i < subitems1.length; i++) {
                    subcombobox.addItem(subitems1[i]);
                }
            }
            else if (maincombobox.getSelectedItem().equals("Blue") ||
                maincombobox.getSelectedItem().equals("Green") ){

                subcombobox.setEnabled(true);
                subcombobox.removeAllItems();
                for (int i = 0; i < subitems2.length; i++) {
                    subcombobox.addItem(subitems2[i]);
                }
            }
        }
    }
    public static void main(String[] args){
        JFrame frame = new Example2();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300,200);
        frame.setVisible(true);
        frame.setLocationRelativeTo(null); 
    }
}

Answer 1

添加以下代码：

if(e.getSource()==subcombobox){
    int choice=Integer.parseInt(subcombobox.getSelectedItem());
    //here the selected number gets stored into the int variable choice
    labels.setText(fortune[choice]);
    //here the text for "labels" is set from your fortune string array
}

根据您的喜好更改代码，但这本身是不言自明

Answer 2

我写的逻辑完美地检查这个

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
public class Example2 extends JFrame implements ItemListener {
private JComboBox maincombobox;
private JComboBox subcombobox;
private JLabel labels;
public Example2(){
    String[] items = {"Select a Color","Red","Blue","Yellow","Green"};
    maincombobox =  new JComboBox(items);
    maincombobox.addItemListener(this);
    getContentPane().add(maincombobox);
    subcombobox = new JComboBox();
    subcombobox.addItemListener(this);      
    subcombobox.setEnabled(true);
    subcombobox.setPrototypeDisplayValue("XXXXXXXXXXXXX");
    getContentPane().add(subcombobox,BorderLayout.EAST);
    labels =  new JLabel("Default");
    getContentPane().add(labels, BorderLayout.SOUTH);

         }
public void itemStateChanged(ItemEvent e) {
    String[] subitems1 = {"Choose a number","1","3","4","7"};
    String[] subitems2= {"Choose a number","2","6","8","5"};
    String[] fortune = {"Today is you lucky day", "You will get strange looks from people", "Don't touch your left foot today", 
            "You will forget a crucial thing today", "You will meet a mysterious person", "Will win a million dollars", 
            "Good day in the financial market", "Get a life","Think hard, you will find the answer"};
    if (e.getSource() == maincombobox)
    {
        if (maincombobox.getSelectedItem().equals("Select a Color"))
        {
            subcombobox.setEnabled(false);
        }
        else if (maincombobox.getSelectedItem().equals("Red") || maincombobox.getSelectedItem().equals("Yellow"))
        {
            subcombobox.setEnabled(true);
            subcombobox.removeAllItems();
            for (int i = 0; i < subitems1.length; i++)
            {
                subcombobox.addItem(subitems1[i]);
            }
        }
        else if (maincombobox.getSelectedItem().equals("Blue") || maincombobox.getSelectedItem().equals("Green"))
        {
            subcombobox.setEnabled(true);
            subcombobox.removeAllItems();
            for (int i = 0; i < subitems2.length; i++)
            {
                subcombobox.addItem(subitems2[i]);
            }
        }
    }

    else if (subcombobox.getItemCount()>0)
    {
        for(int i=0;i<8;i++)
        {
                if (subcombobox.getSelectedItem().equals(Integer.toString(i)))
                {
                    labels.setText(fortune[i]);
                }
        }
    }
}
public static void main(String[] args){
    JFrame frame = new Example2();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300,200);
    frame.setVisible(true);
    frame.setLocationRelativeTo(null); 
}

}

我刚刚在底部添加了代码是

else if (subcombobox.getItemCount()>0)
{
    for(int i=0;i<8;i++)
    {
            if (subcombobox.getSelectedItem().equals(Integer.toString(i)))
            {
                labels.setText(fortune[i]);
            }
    }
}

如果有效，请勾选它作为正确答案