我正在编写此程序以保留导师的日志。目的是让学生“登录”他/她的信息。我几乎完成了所有代码，除了我无法在第二帧上获取ADD按钮以将文本输入添加到日志中。这就是我所拥有的：
package gui;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;
public class MainGUI extends JFrame {
// Declare variables:
// array lists
String[] columnNames = {"ID", "NAME", "COURSE", "Professor", "Reason for Tutor"};
Object[][] data = new Object[25][5];
// table
JTable table = new JTable(data, columnNames) {
// sets the ability of the cells to be edited by the user
@Override
public boolean isCellEditable(int row, int column) {
return false; // returns false, cannot be edited
}
};
// frames
JFrame frame, frame1;
// panels
JPanel buttonPanel, buttonPanel2, tablePanel, addPanel, editPanel;
// labels
JLabel labelID, labelName, labelCourse, labelProfessor, labelHelp;
// text fields
JTextField txtID, txtName, txtCourse, txtProfessor, txtHelp;
// buttons
JButton btnAdd, btnEdit, btnDelete, btnSort, btnSave, btnAddInput, btnCancel;
// additionals
int keyCode, rowIndex, rowNumber, noOfStudents;
// button handler
ButtonHandler bh = new ButtonHandler();
public MainGUI() {
// setting/modifying table components
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.getSelectionModel().addListSelectionListener(new RowListener());
table.getColumnModel().getColumn(1).setPreferredWidth(200);
table.getColumnModel().getColumn(3).setPreferredWidth(100);
table.getColumnModel().getColumn(4).setPreferredWidth(200);
table.getTableHeader().setResizingAllowed(false);
table.getTableHeader().setReorderingAllowed(false);
JScrollPane scrollPane = new JScrollPane(table);
// main buttons
btnAdd = new JButton("ADD");
btnAdd.addActionListener(bh);
btnEdit = new JButton("EDIT");
btnEdit.addActionListener(bh);
btnEdit.setEnabled(false); // disables the component
btnDelete = new JButton("DELETE");
btnDelete.addActionListener(bh);
btnDelete.setEnabled(false); // disables the component
btnSort = new JButton("SORT");
btnSort.addActionListener(bh);
btnSave = new JButton("SAVE");
btnSave.addActionListener(bh);
// with button Listeners
// sub buttons
btnAddInput = new JButton("Add");
btnAddInput.addActionListener(bh);
btnCancel = new JButton("Cancel");
btnCancel.addActionListener(bh);
// set label names
labelID = new JLabel("ID");
labelName = new JLabel("NAME");
labelCourse = new JLabel("COURSE");
labelProfessor = new JLabel("Professor");
labelHelp = new JLabel("Reason for Tutoring");
// set text fields width
txtID = new JTextField(20);
txtName = new JTextField(20);
txtCourse = new JTextField(20);
txtProfessor = new JTextField(20);
txtHelp = new JTextField(20);
txtID.setDocument(new JTextFieldLimit(15)); // limits the length of input:
// max of 15
txtID.addKeyListener(keyListener); // accepts only numerals
// main frame
// panel for the table
tablePanel = new JPanel();
tablePanel.setLayout(new BoxLayout(tablePanel, BoxLayout.PAGE_AXIS));
tablePanel.setBorder(BorderFactory.createEmptyBorder(10, 2, 0, 10));
tablePanel.add(table.getTableHeader());
tablePanel.add(table);
// panel for the main buttons
buttonPanel = new JPanel();
buttonPanel.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
// positions the main buttons
c.gridx = 0;
c.gridy = 0;
c.ipady = 20;
c.insets = new Insets(10, 10, 10, 10);
c.fill = GridBagConstraints.HORIZONTAL;
buttonPanel.add(btnAdd, c);
c.gridx = 0;
c.gridy = 1;
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 20;
c.insets = new Insets(10, 10, 10, 10);
buttonPanel.add(btnEdit, c);
c.gridx = 0;
c.gridy = 2;
c.fill = GridBagConstraints.HORIZONTAL;
c.ipady = 20;
c.insets = new Insets(10, 10, 10, 10);
buttonPanel.add(btnDelete, c);
c.gridx = 0;
c.gridy = 3;
c.ipady = 20;
c.insets = new Insets(10, 10, 10, 10);
c.fill = GridBagConstraints.HORIZONTAL;
buttonPanel.add(btnSort, c);
c.gridx = 0;
c.gridy = 4;
c.ipady = 20;
c.insets = new Insets(10, 10, 10, 10);
c.fill = GridBagConstraints.HORIZONTAL;
buttonPanel.add(btnSave, c);
frame = new JFrame("Student Database");
frame.setVisible(true);
frame.setResizable(false);
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.add(tablePanel, BorderLayout.CENTER);
frame.add(buttonPanel, BorderLayout.EAST);
frame.pack();
// ADD frame
// panel for adding
addPanel = new JPanel();
addPanel.setLayout(new GridBagLayout());
// positions the components for adding
// labels
c.insets = new Insets(1, 0, 1, 1);
c.gridx = 0;
c.gridy = 0;
addPanel.add(labelID, c);
c.gridy = 1;
addPanel.add(labelName, c);
c.gridy = 2;
addPanel.add(labelCourse, c);
c.gridy = 3;
addPanel.add(labelProfessor, c);
c.gridy = 4;
addPanel.add(labelHelp, c);
// text fields
c.gridx = 1;
c.gridy = 0;
c.ipady = 1;
addPanel.add(txtID, c);
c.gridy = 1;
c.ipady = 1;
addPanel.add(txtName, c);
c.gridy = 2;
c.ipady = 1;
addPanel.add(txtCourse, c);
c.gridy = 3;
c.ipady = 1;
addPanel.add(txtProfessor, c);
c.gridy = 4;
c.ipady = 1;
addPanel.add(txtHelp, c);
// panel for other necessary buttons
buttonPanel2 = new JPanel();
buttonPanel2.setLayout(new GridLayout(1, 1));
buttonPanel2.add(btnAddInput);
buttonPanel2.add(btnCancel);
frame1 = new JFrame("Student Database");
frame1.setVisible(false);
frame1.setResizable(false);
frame1.setDefaultCloseOperation(HIDE_ON_CLOSE);
frame1.add(addPanel, BorderLayout.CENTER);
frame1.add(buttonPanel2, BorderLayout.PAGE_END);
frame1.pack();
}// end
KeyListener keyListener = new KeyListener() {
@Override
public void keyTyped(KeyEvent e) {
}
@Override
public void keyPressed(KeyEvent e) {
keyCode = e.getKeyCode();
if (!(keyCode >= 48 && keyCode <= 57) && !(keyCode >= 96 && keyCode <= 105)
&& !(keyCode >= 37 && keyCode <= 40) && !(keyCode == 127 || keyCode == 8)) {
txtID.setEditable(false);
}
}
@Override
public void keyReleased(KeyEvent e) {
txtID.setEditable(true);
}
};
class RowListener implements ListSelectionListener {
@Override
public void valueChanged(ListSelectionEvent event) {
if (event.getValueIsAdjusting()) {
rowIndex = table.getSelectedRow();
if (data[rowIndex][0] == null || data[rowIndex][0] == "") {
btnEdit.setEnabled(false);
btnDelete.setEnabled(false);
} else {
btnEdit.setEnabled(true);
btnDelete.setEnabled(true);
}
}
}
}// end
class ButtonHandler implements ActionListener {
@Override
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("ADD")) {
// text fields for Student input data
txtID.setText("");
txtName.setText("");
txtCourse.setText("");
txtProfessor.setText("");
txtHelp.setText("");
frame1.setTitle("Add Student data"); // title bar name for add
btnAddInput.setActionCommand("ADD");
btnAddInput.setText("ADD");
frame1.setVisible(true);
} if (e.getActionCommand().equals("EDIT")) {
txtID.setText(data[rowIndex][4] + ""); // will preview the ID
// input during Add
txtName.setText(data[rowIndex][1] + ""); // will preview the Name
// input during Add
txtCourse.setText(data[rowIndex][2] + ""); // will preview the
// Course input during
// Add
txtProfessor.setText(data[rowIndex][3] + ""); // will preview the Year
// input during Add
txtHelp.setText(data[rowIndex][0] + ""); // will preview the
// Gender input during
// Add
txtID.setEditable(false); // forbids the user to edit the entered
// ID number
frame1.setTitle("Edit Student data"); // title bar name for edit
btnAddInput.setActionCommand("Edit2");
btnAddInput.setText("ACCEPT");
frame1.setVisible(true); // sets the visibility of frame1
} else if (e.getActionCommand().equals("DELETE")) {
int confirm = JOptionPane.showConfirmDialog(frame, "ARE YOU SURE?", "CONFIRM",
JOptionPane.YES_NO_OPTION);
if (confirm == 0) {
rowIndex = table.getSelectedRow();
rowNumber = 0;
noOfStudents--;
for (int i = 0; i <= 10; i++) {
if (rowIndex != i && i <= noOfStudents) {
data[rowNumber][4] = data[i][4];
data[rowNumber][1] = data[i][1];
data[rowNumber][2] = data[i][2];
data[rowNumber][3] = data[i][3];
data[rowNumber][0] = data[i][0];
rowNumber++;
} else if (rowIndex != i && i > noOfStudents) {
data[rowNumber][4] = "";
data[rowNumber][1] = "";
data[rowNumber][2] = "";
data[rowNumber][3] = "";
data[rowNumber][0] = "";
rowNumber++;
}
}
if (noOfStudents == 1000) {
btnAdd.setEnabled(false);
}
else {
btnAdd.setEnabled(true);
} // continues to add students if
// not equal to 50
if (noOfStudents == 0) {
btnDelete.setEnabled(false);
btnEdit.setEnabled(false);
} else {
btnDelete.setEnabled(true);
btnEdit.setEnabled(true);
}
rowIndex = table.getSelectedRow();
if (data[rowIndex][0] == null || data[rowIndex][0] == "") {
btnEdit.setEnabled(false);
btnDelete.setEnabled(false);
} else {
btnEdit.setEnabled(true);
btnDelete.setEnabled(true);
}
table.updateUI();
} else if (e.getActionCommand().equals("Add")) {
if (txtID.getText().isEmpty() || txtName.getText().isEmpty()
|| txtCourse.getText().isEmpty()// /
|| txtProfessor.getText().isEmpty() || txtHelp.getText().isEmpty()) {
JOptionPane.showMessageDialog(null, "PLEASE FILL IN THE BLANKS.", "ERROR!",
JOptionPane.ERROR_MESSAGE);
}
else {
int dup = 0;
for (int i = 0; i < 10; i++) {
if (txtID.getText().equals(data[i][0])) {
JOptionPane.showMessageDialog(null, "ID NUMBER ALREADY EXISTS.", "ERROR!",
JOptionPane.ERROR_MESSAGE);
dup++;
}
}
if (dup == 0) {
rowIndex = table.getSelectedRow();
data[noOfStudents][4] = txtID.getText();
data[noOfStudents][1] = txtName.getText();
data[noOfStudents][2] = txtCourse.getText();
data[noOfStudents][3] = txtProfessor.getText();
data[noOfStudents][0] = txtHelp.getText();
table.updateUI();
frame1.dispose();
noOfStudents++;
if (noOfStudents == 50){
btnAdd.setEnabled(false);
}
else {
btnAdd.setEnabled(true);
}
if (data[rowIndex][0] == null) {
btnEdit.setEnabled(false);
btnDelete.setEnabled(false);
} else {
btnEdit.setEnabled(true);
btnDelete.setEnabled(true);
}
}
}
table.updateUI();
} else if (e.getActionCommand().equals("Edit2")) {
if (txtID.getText().isEmpty() || txtName.getText().isEmpty()
|| txtCourse.getText().isEmpty() || txtProfessor.getText().isEmpty()
|| txtHelp.getText().isEmpty()) {
JOptionPane.showMessageDialog(null, "INCOMPLETE INPUT.", "ERROR!",
JOptionPane.ERROR_MESSAGE);
} else {
data[rowIndex][4] = txtID.getText();
data[rowIndex][1] = txtName.getText();
data[rowIndex][2] = txtCourse.getText();
data[rowIndex][3] = txtProfessor.getText();
data[rowIndex][0] = txtHelp.getText();
frame1.dispose();
}
table.updateUI();
} else if (e.getActionCommand().equals("Cancel")) {
frame1.dispose();
}
}
}
}// end
class JTextFieldLimit extends PlainDocument {
private int limit;
JTextFieldLimit(int limit) {
super();
this.limit = limit;
}
JTextFieldLimit(int limit, boolean upper) {
super();
this.limit = limit;
}
@Override
public void insertString(int offset, String str, AttributeSet attr)
throws BadLocationException {
if (str == null) {
return;
}
if ((getLength() + str.length()) <= limit) {
super.insertString(offset, str, attr);
}
}
}
public static void main(String[] args) {
new MainGUI();
}// end of main
}
答案 0 :(得分：2)
问题＃1 - 您正在将ActionCommand重新设置为btnAddItem为“ADD”，这将与您的btnAdd命令冲突。
在创建btnAddItem的第71行之后，添加动作命令，并使其与btnAdd项不同（不仅仅是大小写）：
btnAddInput.setActionCommand("AddInput");
然后删除这两行（第247行），因为它们不再需要了：
btnAddInput.setActionCommand("ADD");
btnAddInput.setText("ADD");
然后我们将在第326行更改您的侦听器子句以匹配。改变这个：
} else if (e.getActionCommand().equals("Add")) {
为：
} else if (e.getActionCommand().equals("AddInput")) {
最后，你有一套错位的括号。
在第391行（在//结尾之前的行右侧）删除关闭括号}，然后在第325行添加它，就在此行之前：
} else if (e.getActionCommand().equals("Add")) {
你正在做其他一些不好的事情 - 你不应该改变ActionCommands，或者将所有这些东西放在一个ButtonHandler中，但这会让你超越你的直接问题。