如何在JCombBox中进行选择时使JLabel更改图像

时间:2013-01-25 19:28:46

标签: java swing jlabel jcombobox

我希望每次用户在JLabel中选择从文本文件中获取其值的选项时进行JComboBox更改,请真正需要帮助....

import javax.swing.*;
import javax.swing.border.*;
import java.util.*;
import java.util.List;
import java.io.IOException;
import java.util.Scanner;
import java.io.*;
import java.awt.*;
import java.awt.event.*; 
import java.net.*;
import java.applet.*;

public class MusicOnWeb extends JApplet {
    JPanel P = new JPanel();

    JLabel Title = new JLabel();
        JLabel Logo = new JLabel();
            JLabel Category = new JLabel();
            JLabel List = new JLabel();
            JLabel Image = new JLabel();
            JSeparator jSeparator1 = new JSeparator();
            JSeparator jSeparator2 = new JSeparator();
            JSeparator jSeparator3 = new JSeparator();
            JSeparator jSeparator4 = new JSeparator();
            JSeparator jSeparator5 = new JSeparator();
            JButton Cc = new JButton();
            JButton Pp = new JButton();
            JButton Jz = new JButton();
            JButton Wn = new JButton();
            JButton Cart = new JButton();
            JComboBox Combo1 = new JComboBox();
            JComboBox Combo2 = new JComboBox();
            JComboBox Combo3 = new JComboBox();
            JComboBox Combo4 = new JComboBox();

        Font f = new Font("Lucida Calligraphy", Font.BOLD,25);

    final java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("MMMM dd yyyy GGG hh:mm:ss aaa"); 
    JLabel TimeLabel = new JLabel();

     ActionListener al = new ActionListener() {  
        public void actionPerformed(ActionEvent ae) {  
                    TimeLabel.setText(sdf.format(new java.util.Date())); 
            }  
        };

    String[] CB1 = new String[5];
    String[] CB2 = new String[5];
    String[] CB3 = new String[5];
    String[] CB4 = new String[5];

    String Music [ ] = {" Seal.jpg"};

    GridBagConstraints gbc;

public void init() {
        P.setBackground(new Color(102, 102, 102));
        P.setBorder(javax.swing.BorderFactory.createCompoundBorder(javax.swing.BorderFactory.createBevelBorder(javax.swing.border.BevelBorder.RAISED, new java.awt.Color(255, 0, 51), new java.awt.Color(0, 153, 255), new java.awt.Color(0, 204, 153), new java.awt.Color(0, 204, 102)), javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0), 3)));
        P.setLayout(new GridBagLayout());

 try {
    File F= new File("Classics.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB1[i] = inFile.nextLine();
    i++;
}} catch (Exception e) {

    }

 try {
    File F= new File("Western.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB2[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

 try {
    File F= new File("Pop.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB4[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

 try {
    File F= new File("Jazz.txt");
    Scanner inFile = new Scanner(new FileReader(F)).useDelimiter("\\' '| \r");
    int i=0;
    while (inFile.hasNextLine()){
    CB3[i] = inFile.nextLine();
    i++;
}}catch (Exception e)  {

    }

        Title.setFont(new Font("Lucida Calligraphy", 1, 27)); 
        Title.setForeground(new Color(102, 102, 255));
        Title.setHorizontalAlignment(SwingConstants.CENTER);
        Title.setText("<HTML><center><b><u>MusicOnWeb</u></b><BR>An Online Music Store</HTML>");
        Title.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0)));
        gbc = new GridBagConstraints();
        gbc.gridx = 1;
        gbc.gridy = 0;
        gbc.gridwidth = 10;
        gbc.ipadx = 440;    // To resize components
        gbc.ipady = 25;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 45, 0, 0);     // To move components
        P.add(Title, gbc);

        Logo.setIcon(new ImageIcon("C:\\Users\\Kwasi Addai\\Documents\\Java Work\\Project 1\\Logo.jpg"));
        Logo.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0)));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.ipadx = -52;
        gbc.ipady = -23;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 46, 0, 0);
        P.add(Logo, gbc);

        Category.setFont(new Font("Kristen ITC", 1, 24)); 
        Category.setHorizontalAlignment(SwingConstants.CENTER);
        Category.setText("Select the Category");
        Category.setBorder(javax.swing.BorderFactory.createEtchedBorder(javax.swing.border.EtchedBorder.RAISED, new Color(102, 204, 255), java.awt.Color.red));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 2;
        gbc.gridwidth = 3;
        gbc.ipadx = 30;
        gbc.ipady = 13;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 46, 0, 0);
        P.add(Category, gbc);

        List.setFont(new Font("Britannic Bold", 0, 27)); 
        List.setHorizontalAlignment(SwingConstants.CENTER);
        List.setText("List of CD's Available");
        List.setBorder(javax.swing.BorderFactory.createEtchedBorder(java.awt.Color.black, java.awt.Color.white));
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 2;
        gbc.gridwidth = 16;
        gbc.gridheight = 2;
        gbc.ipadx = 248;
        gbc.ipady = 22;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(23, 17, 0, 0);
        P.add(List, gbc);

        Image.setBorder(javax.swing.BorderFactory.createLineBorder(new Color(0, 0, 0), 3));
        Image.setMaximumSize(new Dimension(300, 300));
        Image.setMinimumSize(new Dimension(300, 300));
        gbc = new GridBagConstraints();
        gbc.gridx = 9;
        gbc.gridy = 5;
        gbc.gridwidth = 12;
        gbc.gridheight = 9;
        gbc.ipadx = -12;
        gbc.ipady = -12;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(8, 40, 0, 0);
        P.add(Image, gbc);

        TimeLabel.setText("timeLabel");
        TimeLabel.setFont(f);
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 16;
        gbc.gridwidth = 0;
        gbc.ipadx = 278;
        gbc.ipady = 33;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(15, 40, 0, 0);
        P.add(TimeLabel, gbc);
    new javax.swing.Timer(1000,al).start();  

        jSeparator1.setForeground(new Color(102, 102, 102));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.gridwidth = 23;
        gbc.ipadx = 958;
        gbc.ipady = 3;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(20, 15, 0, 16);
        P.add(jSeparator1, gbc);

        jSeparator2.setBackground(new Color(0, 0, 0));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 4;
        gbc.gridwidth = 4;
        gbc.ipadx = 340;
        gbc.ipady = 2;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(9, 15, 0, 0);
        P.add(jSeparator2, gbc);

        jSeparator3.setOrientation(SwingConstants.VERTICAL);
        gbc = new GridBagConstraints();
        gbc.gridx = 4;
        gbc.gridy = 2;
        gbc.gridheight = 13;
        gbc.ipadx = 11;
        gbc.ipady = 450;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(-2, 1, 0, 0);
        P.add(jSeparator3, gbc);

        jSeparator4.setBackground(new Color(0, 0, 0));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 15;
        gbc.gridwidth = 23;
        gbc.ipadx = 958;
        gbc.ipady = 1;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(0, 15, 0, 16);
        P.add(jSeparator4, gbc);

        jSeparator5.setOrientation(SwingConstants.VERTICAL);
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 16;
        gbc.gridheight = 3;
        gbc.ipadx = 11;
        gbc.ipady = 95;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(0, 180, 10, 0);
        P.add(jSeparator5, gbc);

        Cc.setFont(new Font("Tahoma", 3, 20)); 
        Cc.setForeground(new Color(0, 0, 102));
        Cc.setText("Classic");
        Cc.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 5;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 161;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(29, 65, 0, 0);
        Cc.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB1));
                Combo2.setModel(new DefaultComboBoxModel(CB1));
                Combo3.setModel(new DefaultComboBoxModel(CB1));
                Combo4.setModel(new DefaultComboBoxModel(CB1));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
         P.add(Cc, gbc);

        Pp.setFont(new Font("Tahoma", 3, 20)); 
        Pp.setForeground(new Color(0, 204, 204));
        Pp.setText("Pop");
        Pp.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 9;
        gbc.gridwidth = 2;
        gbc.ipadx = 191;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(16, 65, 0, 0);
        Pp.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB4));
                Combo2.setModel(new DefaultComboBoxModel(CB4));
                Combo3.setModel(new DefaultComboBoxModel(CB4));
                Combo4.setModel(new DefaultComboBoxModel(CB4));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
        P.add(Pp, gbc);

        Jz.setFont(new Font("Tahoma", 3, 20)); 
        Jz.setForeground(new Color(0, 51, 153));
        Jz.setText("Jazz");
        Jz.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 11;
        gbc.gridwidth = 2;
        gbc.ipadx = 185;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(12, 65, 0, 0);
          Jz.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB3));
                Combo2.setModel(new DefaultComboBoxModel(CB3));
                Combo3.setModel(new DefaultComboBoxModel(CB3));
                Combo4.setModel(new DefaultComboBoxModel(CB3));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });
        P.add(Jz, gbc);

        Wn.setFont(new Font("Tahoma", 3, 20)); 
        Wn.setForeground(new Color(0, 102, 102));
        Wn.setText("Western");
        Wn.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 4, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 7;
        gbc.gridwidth = 2;
        gbc.ipadx = 145;
        gbc.ipady = 17;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 65, 0, 0);
          Wn.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Combo1.setModel(new DefaultComboBoxModel(CB2));
                Combo2.setModel(new DefaultComboBoxModel(CB2));
                Combo3.setModel(new DefaultComboBoxModel(CB2));
                Combo4.setModel(new DefaultComboBoxModel(CB2));
                Combo1.setSelectedIndex(0);
                Combo2.setSelectedIndex(0);
                Combo3.setSelectedIndex(0);
                Combo4.setSelectedIndex(0);
            }
        });

        P.add(Wn, gbc);

        Cart.setFont(new Font("Wide Latin", 1, 24)); 
        Cart.setText("Add to Cart");
        Cart.setBorder(new javax.swing.border.LineBorder(new Color(0, 0, 0), 5, true));
        gbc = new GridBagConstraints();
        gbc.gridx = 7;
        gbc.gridy = 16;
        gbc.gridwidth = 3;
        gbc.gridheight = 2;
        gbc.ipadx = 53;
        gbc.ipady = 14;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(26, 75, 0, 0);
    Cart.addActionListener(new ActionListener() {
              @Override
    public void actionPerformed(ActionEvent evt) {
    AppletContext ac = getAppletContext();
    URL url = getCodeBase(); // get url of this applet

    try {
    ac.showDocument(new URL(url+"Shopping_Cart.html"));
    } catch(MalformedURLException e) 
    {
        showStatus("URL not found");

        }
    }});
        P.add(Cart, gbc);

        Combo1.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 102, 204)));
        Combo1.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 5;
        gbc.gridwidth = 0;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(23, 17, 0, 0);

        P.add(Combo1, gbc);

        Combo2.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 204, 204)));
        Combo2.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 7;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(16, 17, 0, 0);
        P.add(Combo2, gbc);

        Combo3.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 153, 153)));
        Combo3.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 9;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 17, 0, 0);
        P.add(Combo3, gbc);

        Combo4.setBorder(javax.swing.BorderFactory.createMatteBorder(5, 5, 5, 5, new Color(0, 0, 204)));
        Combo4.setPrototypeDisplayValue("XXXXXXXXXXXX");
        gbc = new GridBagConstraints();
        gbc.gridx = 6;
        gbc.gridy = 11;
        gbc.gridwidth = 2;
        gbc.gridheight = 2;
        gbc.ipadx = 103;
        gbc.ipady = 28;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.insets = new Insets(18, 17, 0, 0);
        P.add(Combo4, gbc);

       GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(layout.createParallelGroup(GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(P, GroupLayout.PREFERRED_SIZE, 970, GroupLayout.PREFERRED_SIZE)
                .addContainerGap()));
        layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(P, GroupLayout.PREFERRED_SIZE, 700, GroupLayout.PREFERRED_SIZE)
                .addGap(0, 68, Short.MAX_VALUE)));
      }
}

2 个答案:

答案 0 :(得分:5)

基本概念很简单。

我倾向于使用ItemListener,因为它对不同类型的选择输入更敏感,然后ActionListener

public class TestComboBox05 {

    public static void main(String[] args) {
        new TestComboBox05();
    }

    public TestComboBox05() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

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

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new GridBagLayout());
            final JLabel lbl = new JLabel();
            add(lbl);
            JComboBox cb = new JComboBox();

            cb.addItemListener(new ItemListener() {
                @Override
                public void itemStateChanged(ItemEvent e) {
                    if (e.getStateChange() == ItemEvent.SELECTED) {
                        lbl.setText(e.getItem().toString());
                    }
                }
            });

            cb.addItem("1");
            cb.addItem("2");
            cb.addItem("3");
            cb.addItem("4");
            cb.addItem("5");
            add(cb);

        }

    }

}

基本上,当触发itemStateChanged事件时,您需要找到所选项目并相应地更改标签的图标。此示例显示更改文本,但概念是相同的。

答案 1 :(得分:3)

这是伪代码。

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

public class ChangeJlableByJComboBox extends JFrame {

    private static final long serialVersionUID = 1L;

    public ChangeJlableByJComboBox() {
        super("TooltipInSwing");
        setSize(400, 300);
        getContentPane().setLayout(new FlowLayout());
        final JLabel b1;
        final JComboBox jb1 = new JComboBox(new String[] { " ", "one", "two",
                "three" });

        b1 = new JLabel("Default Lable");
        getContentPane().add(b1);
        getContentPane().add(jb1);

        jb1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                // setting custom text to JLabel
                if (jb1.getSelectedItem().toString().equals("one"))
                    b1.setText("Lable one ---");
                else if (jb1.getSelectedItem().toString().equals("two"))
                    b1.setText("Lable two ---");
                else if (jb1.getSelectedItem().toString().equals("three"))
                    b1.setText("Lable three ---");
                else
                    b1.setText("----");

                // or Compact version for setting JcomboBox selected item 
                // to JLabel text

                // b1.setText(jb1.getSelectedItem().toString());
                System.out.println(jb1.getSelectedItem().toString());
                // you can also make use of following method
                System.out.println(jb1.getSelectedIndex());
            }
        });

        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        setVisible(true);
    }

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

我希望这可以帮助您解决问题。