【发布时间】：2023-12-25 13:41:01
【问题描述】：
我创建了一个程序，我可以在其中在 JTextField 中输入数据，并在点击保存按钮时使用 JFileChooser 将数据保存在 .txt 文件中，其中每个 JTextField 都在一个新行中。我还创建了一个按钮，它会弹出一个 JFileChooser 来浏览该文件并填充其相应的单元格。
我是 GUI 新手，我编写的代码不起作用。我尝试了不同的变化，但似乎无法得到它。请有人指出我正确的方向。
输入是
john
Doe
st. Jude
100
这里是代码
import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.table.DefaultTableModel;
import java.util.Scanner
import java.util.Vector;
import java.awt.event.*;
import java.awt.*;
import java.text.DecimalFormat;
import java.io.*;
//import javax.swing.filechooser;
import javax.swing.filechooser.FileFilter;
public class Charity
{
@SuppressWarnings("deprecation")
public static void main(String[] args)
{
JFrame frame = new JFrame("Learning Team Charity Program");
Container cp = frame.getContentPane();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// Charities
final String[] charityArray = {"St.Jude", "CHOC", "Cancer Research", "AIDs Foundation", "Crohns Foundation"};
final JComboBox selector = new JComboBox(charityArray);
JPanel first = new JPanel();
first.setLayout(new FlowLayout());
first.add(selector);
// User input JLabels and JTextFields
JLabel nameLabel = new JLabel("First Name: ");
final JTextField name = new JTextField();
JLabel lastLabel = new JLabel("Last Name: ");
final JTextField lastname = new JTextField();
JLabel donationAmount = new JLabel("Donation Amount: ");
final JTextField donation = new JTextField();
JPanel second = new JPanel();
second.setLayout(new GridLayout(4,2));
second.add(nameLabel); second.add(name);
second.add(lastLabel); second.add(lastname);
second.add(donationAmount); second.add(donation);
// Donate & Exit Buttons
JButton donateButton = new JButton("Donate");
JButton saveButton = new JButton("Save");
JButton exitButton = new JButton("Exit");
JButton openButton= new JButton("Open File");
JPanel third = new JPanel();
third.setLayout(new FlowLayout());
third.add(donateButton);
third.add(saveButton);
third.add(openButton);
third.add(exitButton);
// JTable display
final DefaultTableModel model = new DefaultTableModel();
JTable table = new JTable(model);
model.addColumn("First Name");
model.addColumn("Last Name");
model.addColumn("Charity");
model.addColumn("Donation");
table.setShowHorizontalLines(true);
table.setRowSelectionAllowed(true);
table.setColumnSelectionAllowed(true);
JScrollPane scrollPane = JTable.createScrollPaneForTable(table);
JPanel fourth = new JPanel();
fourth.setLayout(new BorderLayout());
fourth.add(scrollPane, BorderLayout.CENTER);
// Button Events
exitButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
System.exit(1);
}
});
openButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e){
JFileChooser openChooser = new JFileChooser();
int openStatus = openChooser.showOpenDialog(null);
if(openStatus == JFileChooser.APPROVE_OPTION){
try{
File myFile = openChooser.getSelectedFile();
BufferedReader br = new BufferedReader(new FileReader(myFile));
String line;
while((line = br.readLine())!= null){
model.addRow(line.split(","));
}//end while
br.close();
}//end try
catch(Exception e2){
JOptionPane.showMessageDialog(null, "Buffer Reader Error");
}//end catch
}
}
private void setValueAt(String line, int row, int col) {
// TODO Auto-generated method stub
}
});
saveButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e){
JFileChooser fileChooser = new JFileChooser();
int status = fileChooser.showSaveDialog(null);
if (status == JFileChooser.APPROVE_OPTION)
{
fileChooser.addChoosableFileFilter(new FileNameExtensionFilter("Text", ".txt", "txt"));
//fileChooser.setFileFilter(new FileFilter("txt"));
PrintWriter output;
try {
File file = fileChooser.getSelectedFile();
output = new PrintWriter(file +".txt");
for(int row = 0; row<table.getRowCount(); row++){
for(int col = 0; col<table.getColumnCount();col++){
output.println(table.getValueAt(row, col).toString());
}
output.println();
}
output.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
});
donateButton.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent e)
{
DecimalFormat df = new DecimalFormat("##,###.00");
try
{
Object[] rows = new Object[]{name.getText(), lastname.getText(), selector.getSelectedItem(),
donation.getText()};
model.addRow(rows);
name.setText("");
lastname.setText("");
donation.setText("");
}
catch (Exception ex)
{
JOptionPane.showMessageDialog(null, "Enter a Dollar Amount", "Alert", JOptionPane.ERROR_MESSAGE);
return;
}
}
});
// Frame Settings
frame.setSize(470,300);
//frame.setLocation(300,200);
cp.setLayout(new BoxLayout(cp, BoxLayout.Y_AXIS));
cp.add(first);
cp.add(second);
cp.add(third);
cp.add(fourth);
frame.setVisible(true);
}
}
【问题讨论】：
-
使用 DefaultTableModel 并调用其
addRow(...)方法来添加行。另外，不要使用==或!=比较字符串。请改用equals(...)或equalsIgnoreCase(...)方法。了解==检查两个 对象引用 是否相同，这不是您感兴趣的。另一方面，这些方法检查两个字符串是否以相同的顺序具有相同的字符，这就是这里的重点。 -
谢谢。我知道我必须在 addRow 之后的括号中传递一个值。我已经在将数据保存到文本文件中的按钮中完成了它。我只是不知道要传递什么来显示数据。
标签： java swing jtable jtextfield