JComboBox动作监听器 [英] JComboBox Action listener

问题描述

我遇到了这个问题。
我有多个JComboBox（总共5个）。

I'm having this problem. I have multiple JComboBoxes (5 total).

对于每个comboBox，我添加了一个ActionListener，但所有这些都是相同的ActionListener，名为：

To each comboBox I add an ActionListener, but the same ActionListener for all of them, called:

ComboBoxActionPerformed(java.awt.event.ActionEvent e)

当执行该操作时，我会查看事件（e）并执行：

and when that action is performed I look at the event (e) and do:

JComboBox c = ((JComboBox)e.getSource());
//DO WORK relating to c as thats the combobox that triggered.

但问题是当我在任何组合框中更改某些内容时，Action始终由最后一个触发我附加actionlistner的组合框。

but the problem is when I change something in any of my comboboxes the Action is always triggered by the last combo box to which I am attaching the actionlistner.

任何人都有任何想法吗？

anyone have any idea?

然后我切换到ItemListner 。
这就是我在做什么

I then switched to ItemListner. This is what im doing a

class MyActionListner implements ItemListener 
{
    //STUFF
        @Override
        public void itemStateChanged(ItemEvent evt) 
        {
            //DO STUFF
    }
}

public JComboBox createCombo()
{
    JComboBox box = new JComboBox();
        box.setModel(new javax.swing.DefaultComboBoxModel(new String[] 
                { "val1", "val2","val3" }));
        RulesActionListner actionL = new RulesActionListner();
        box.addItemListener(actionL);
return box;
}

并且createCombo被多次调用
，但不管是哪个组合框item在我的ItemStateChanged方法中被更改了它的
来自最后创建的组合框

and createCombo gets called multiple times but regardless of which combo box item was changed in side my ItemStateChanged method its comming from the last combo box that was created

createCombo在运行时被调用，所以我的变量数为组合框。

createCombo is called at runtime, so i have a variable number of comboboxes.

推荐答案

@ user650608你的问题对我来说不明确，你的意思是 - 走这条路，还是错了？，

@user650608 your questions isn't clear for me, do you mean - going this way, or am I wrong ?,

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

public class ComboBoxTwo extends JFrame implements ActionListener, ItemListener {

    private static final long serialVersionUID = 1L;
    private JComboBox mainComboBox;
    private JComboBox subComboBox;
    private Hashtable<Object, Object> subItems = new Hashtable<Object, Object>();

    public ComboBoxTwo() {
        String[] items = {"Select Item", "Color", "Shape", "Fruit", "Size"};
        mainComboBox = new JComboBox(items);
        mainComboBox.addActionListener(this);
        mainComboBox.addItemListener(this);
        //prevent action events from being fired when the up/down arrow keys are used
        //mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
        getContentPane().add(mainComboBox, BorderLayout.WEST);
        subComboBox = new JComboBox();//  Create sub combo box with multiple models
        subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
        subComboBox.addItemListener(this);
        getContentPane().add(subComboBox, BorderLayout.CENTER);
        String[] subItems1 = {"Select Color", "Red", "Blue", "Green"};
        subItems.put(items[1], subItems1);
        String[] subItems2 = {"Select Shape", "Circle", "Square", "Triangle"};
        subItems.put(items[2], subItems2);
        String[] subItems3 = {"Select Fruit", "Apple", "Orange", "Banana"};
        subItems.put(items[3], subItems3);
        String[] subItems4 = {"Select Size", "Big", "Middle", "Small"};
        subItems.put(items[4], subItems4);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        String item = (String) mainComboBox.getSelectedItem();
        Object o = subItems.get(item);
        if (o == null) {
            subComboBox.setModel(new DefaultComboBoxModel());
        } else {
            subComboBox.setModel(new DefaultComboBoxModel((String[]) o));
        }
    }

    @Override
    public void itemStateChanged(ItemEvent e) {
        if (e.getStateChange() == ItemEvent.SELECTED) {
            if (e.getSource() == mainComboBox) {
                if (mainComboBox.getSelectedIndex() != 0) {
                    FirstDialog firstDialog = new FirstDialog(ComboBoxTwo.this,
                            mainComboBox.getSelectedItem().toString(), "Please wait,  Searching for ..... ");
                }
            } 
        }
    }

    private class FirstDialog extends JDialog {

        private static final long serialVersionUID = 1L;

        FirstDialog(final Frame parent, String winTitle, String msgString) {
            super(parent, winTitle);
            setModalityType(Dialog.ModalityType.APPLICATION_MODAL);
            JLabel myLabel = new JLabel(msgString);
            JButton bNext = new JButton("Stop Processes");
            add(myLabel, BorderLayout.CENTER);
            add(bNext, BorderLayout.SOUTH);
            bNext.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent evt) {
                    setVisible(false);
                }
            });
            javax.swing.Timer t = new javax.swing.Timer(1000, new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent e) {
                    setVisible(false);
                }
            });
            t.setRepeats(false);
            t.start();
            setLocationRelativeTo(parent);
            setSize(new Dimension(400, 100));
            setVisible(true);
        }
    }

    public static void main(String[] args) {
        JFrame frame = new ComboBoxTwo();
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

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