我需要显示两个带目录名的连接组合框。有一个包含多个目录的起始路径，这些目录显示在第一个jcombobox中，当选择目录时，子目录需要显示在第二个jcombobox中。第二个jcombobox应该能够选择其中一个子目录。每个子子目录包含多个.txt文件。我设法在两个jcomboboxes上显示目录和子目录，包括文件。
package calc.my.pay;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableModel;
import javax.swing.JComboBox;
import java.awt.Color;
import javax.swing.JTable;
import javax.swing.JScrollPane;
public class CalcMyPay extends JFrame implements ActionListener {
private JPanel contentPane;
private JScrollPane scrollPane;
private JComboBox folderSelector, subFolderSelector;
private File[] directory, subDirectory;
private String subPath, finalSubPath, selectedSubDirectory, finalSubDirectory;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
CalcMyPay frame = new CalcMyPay();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
* @throws IOException
*/
public CalcMyPay()
{
setBackground(Color.LIGHT_GRAY);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(350, 10, 1000, 700);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
scrollPane = new JScrollPane();
scrollPane.setBounds(12, 120, 958, 300);
String startPath = "C:/Users/Zeus/Desktop/Content/";
// The starting path of the file
directory = new File(startPath).listFiles();
// Folders dropdown box
folderSelector = new JComboBox();
folderSelector.setBounds(60, 13, 200, 22);
folderSelector.insertItemAt("Choose directory", 0);
folderSelector.setSelectedIndex(0);
for(int i=0; i < directory.length; i++) {
System.out.println(directory[i]);
folderSelector.addItem(directory[i].getName());
}
contentPane.add(folderSelector);
// Sub folder dropdown box
subFolderSelector = new JComboBox();
subFolderSelector.setBounds(300, 13, 200, 22);
subFolderSelector.insertItemAt("Choose subdirectory", 0);
subFolderSelector.setSelectedIndex(0);
contentPane.add(subFolderSelector);
folderSelector.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// Get the folder dropdown selected item
selectedSubDirectory = folderSelector.getSelectedItem().toString();
//System.out.println("Folder selected: " + Arrays.asList(directory).toString().contains(selectedSubDirectory));
//System.out.println("Subfolders based on folder selected : " + Arrays.asList(directory) + " " + selectedSubDirectory);
//subFolderSelector.addItem(folderSelector.getSelectedItem());
// Check if the array from the main directory contains the selected directory
if(Arrays.asList(directory).toString().contains(selectedSubDirectory)) {
// Make a new file that list all the directories in the given path
subPath = startPath + selectedSubDirectory;
subDirectory = new File(subPath).listFiles();
// Sort the array directory in a descending order
Arrays.sort(subDirectory, Collections.reverseOrder());
// Delete the previous list items, if any
subFolderSelector.removeAllItems();
// Iterate through all the directories in the selected folder
for(int i=0; i < subDirectory.length; i++) {
// Pass only directories (files will be omitted)
// ### Should check if directory contains only 4 numbers here
if(subDirectory[i].isDirectory()) {
//subFolderSelector.addItem(folderSelector.getSelectedItem());
subFolderSelector.addItem(subDirectory[i].getName());
}
}
}
}
});
subFolderSelector.addActionListener(new ActionListener() {
int count = 0;
@Override
public void actionPerformed(ActionEvent e) {
count++;
if(count == 3) {
selectedSubSubDirectory = subFolderSelector.getSelectedItem().toString();
// Make an new file that list all the file in the selected sub folder
if(Arrays.asList(subDirectory).toString().contains(selectedSubDirectory)) {
//textFiles = new File(finalSubPath).listFiles();
subSubPath = startPath + selectedSubDirectory + "/" + selectedSubSubDirectory;
textFiles = new File(subSubPath).listFiles();
for(File file: textFiles) {
if(file.isFile() && file.toString().toLowerCase().endsWith("_110.txt")) {
System.out.println(file);
}
}
}
count = 0;
}
}
});
}
}
但是你可以在subDirectorySelector的第二个actionListener中看到我有一个计数器。那里的代码执行三次（因为第二个jcombobox改变了值）。如果在第一个jcombobox中选择相同的路径两次，则会出错。必须有更好（可能）更短的方法来做到这一点。你会改变什么？
由于
答案 0 :(得分：0)
我尝试制作自己的版本，但它非常相似，只是在更新subFolder选择器之前删除了actionListener，并添加了更多检查。
这是我的代码：
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.util.Arrays;
import java.util.Collections;
import javax.swing.JComboBox;
import javax.swing.JFrame;
public class ComboDemo extends JFrame implements ActionListener {
private String rootDir;
private JComboBox box1;
private JComboBox box2;
/**
* Create the frame.
*/
public ComboDemo () {
super("Demo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
createGui();
this.rootDir = "/home";
setRootDir(new File(this.rootDir));
}
/**
* Create the gui components.
*/
private void createGui () {
this.box1 = new JComboBox();
this.box2 = new JComboBox();
this.box1.addActionListener(this);
this.box2.addActionListener(this);
this.box1.insertItemAt("Choose directory :", 0);
this.box1.setSelectedIndex(0);
this.box2.insertItemAt("Choose subdirectory :", 0);
this.box2.setSelectedIndex(0);
setLayout(new FlowLayout(FlowLayout.LEADING));
add(this.box1);
add(this.box2);
}
/**
* Show the gui.
*/
private void showGui () {
setSize(500, 250);
setLocationRelativeTo(null);
setVisible(true);
}
/**
* Update the first selector with the directories listed under the specified
* root directory.
*
* @param dir
* Root directory.
*/
private void setRootDir (File dir) {
for (File file : dir.listFiles()) {
if (file.isDirectory()) {
this.box1.addItem(file.getName());
}
}
}
@Override
public void actionPerformed (ActionEvent e) {
if (e.getSource() instanceof JComboBox) {
JComboBox box = (JComboBox) e.getSource();
// Box 1
if (this.box1.equals(box)) {
String dirName = box.getSelectedItem().toString();
// RootDir / Folder
File dir = new File(this.rootDir + File.separator + dirName);
System.out.println("# Folder : " + dir.getPath());
// Check if there is a least one file
if (dir.exists() && dir.listFiles().length > 0) {
Arrays.sort(dir.listFiles(), Collections.reverseOrder());
// Reset box2
this.box2.removeAllItems();
this.box2.insertItemAt("Choose subdirectory :", 0);
// Update Box2
this.box2.removeActionListener(this);
for (File file : dir.listFiles()) {
if (file.isDirectory()) {
this.box2.addItem(file.getName());
}
}
this.box2.addActionListener(this);
this.box2.setSelectedIndex(0);
}
}
// Box 2
else if (this.box2.equals(box)) {
// Check if box2 is empty
if (box.getItemCount() > 0) {
String dirName = box.getSelectedItem().toString();
// RootDir / Folder / SubFolder
File dir = new File(this.rootDir + File.separator + this.box1.getSelectedItem().toString()
+ File.separator + dirName);
System.out.println("# SubFolder : " + dir.getPath());
// Check if there is a least one file
if (dir.exists() && dir.listFiles().length > 0) {
Arrays.sort(dir.listFiles(), Collections.reverseOrder());
// Print .txt files
for (File file : dir.listFiles()) {
if (file.isFile() && file.getName().endsWith(".txt")) {
System.out.println("\t" + file.getName());
}
}
}
}
}
}
}
public static void main (String[] args) {
ComboDemo demo = new ComboDemo();
demo.showGui();
}
}