每当我点击Add Employee并输入有关员工的信息时，我希望我的程序更新TextArea。
（我还没有实现Add Produ Worker按钮的代码，因为我无法使Add Employee按钮工作）。
/**
* *****************************************************************************
* Program Name: EmployeeAndProductionWorkerClasses.java Created Date: 1/31/2016 Created By: Tommy Saechao Purpose: The
* main class of this program. This program demonstrates the use of inheritance in Java.
* *****************************************************************************
*/
package pkg10.pkg1.employee.and.productionworker.classes;
import java.awt.*; //Abstract Window ToolKit, Container and Layouts
import java.awt.event.*; //ActionListener, ActionEvent
import javax.swing.*; //Swing classes
public class EmployeeAndProductionWorkerClasses {
//default employee
static Employee defaultEmployee = new Employee();
//default production worker
static ProductionWorker defaultProductionWorker = new ProductionWorker();
public static void main(String[] args) {
//Window sizes
final int WINDOW_WIDTH = 450;
final int WINDOW_HEIGHT = 350;
//Creates a JFrame Window
JFrame window = new JFrame();
//sets the title of the JFrame window
window.setTitle("Employee and Production Worker Classes");
//Sets size of fthe JFrame window
window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);
//Closes the window if the exit button is clicked
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//sets location of the program being displayed on the screen
window.setLocation(200, 200);
//Creates a container using border layout
Container c = window.getContentPane();
c.setLayout(new BorderLayout());
//Add worker button
JButton addEmployeeBtn = new JButton("Add Employee"); //Creates a button for adding Employees
c.add(addEmployeeBtn, BorderLayout.LINE_START); //Adds the addEmployeeBtn to the left side of the container (c)
//Remove worker button
JButton addProductionWorkerBtn = new JButton("Add Production Worker"); //Creates a button for adding Production Workers
c.add(addProductionWorkerBtn, BorderLayout.LINE_END); //Adds the addProductionWorkerBtn to the right side of the container (c)
//View Workers TextArea
JTextArea viewWorkersTA = new JTextArea(defaultEmployee.toString());
c.add(viewWorkersTA, BorderLayout.CENTER);
addEmployeeBtn.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
String name = JOptionPane.showInputDialog("Name: ");
String employeeNumber = JOptionPane.showInputDialog("Employee Number (###-L): ");
String hireDate = JOptionPane.showInputDialog("Hire Date (mm/dd/yyyy): ");
defaultEmployee = new Employee(name, employeeNumber, hireDate);
}
});
//Display the window.
window.setVisible(true); //sets the window frame visible
}
}
员工类
/*******************************************************************************
* Program Name: Employee.java
* Created Date: 1/31/2016
* Created By: Tommy Saechao
* Purpose: A superclass that holds information about a typical employee.
*******************************************************************************/
package pkg10.pkg1.employee.and.productionworker.classes;
import javax.swing.*; //Swing classes
//Employee Class
public class Employee {
private String name; //Holds the employee's name
private String employeeNumber; //Holds the employee's number
private String hireDate; //Holds when the employee was hired
Employee(String name, String employeeNumber, String hireDate) {
this.name = name; //Initializes employee's name
setEmployeeNumber(employeeNumber); //Initializes employee's number
this.hireDate = hireDate; //initializes hireDate
}
//Default constructor
Employee() {
name = ""; //Default name (blank)
employeeNumber = ""; //Default employee number (blank)
hireDate = ""; //Default employee hire date (blank)
}
//Sets the employee's name
public void setName(String name) {
this.name = name;
}
//Returns the employee's name
public String getName() {
return this.name;
}
//Sets the employee's number
private void setEmployeeNumber(String employeeNumber) {
if (isValidEmployeeNumber(employeeNumber)) { //Determines if the employee number given is valid
this.employeeNumber = employeeNumber; //sets employee number
} else {
this.employeeNumber = ""; //sets employee number to default (blank)
}
}
//Returns employee number
private String getEmployeeNumber() {
return employeeNumber;
}
//sets employee's hire date
private void setHireDate(String hireDate) {
this.hireDate = hireDate;
}
//returns employee's hire date
private String getHireDate() {
return hireDate;
}
//determines if an employee number is valid
private boolean isValidEmployeeNumber(String employeeNumber) {
boolean status = true; //default status value
if (employeeNumber.length() != 5) //an employee number is a length of 5 characters
{
status = false;
} else if ((!Character.isDigit(employeeNumber.charAt(0))) //First character must be a digit
|| (!Character.isDigit(employeeNumber.charAt(1))) //Second character must be a digit
|| (!Character.isDigit(employeeNumber.charAt(2))) //Third character must be a digit
|| (employeeNumber.charAt(3) != '-') //fourth character must be a hyphen
|| (Character.toUpperCase(employeeNumber.charAt(4)) < 'A') //4th character must be in between letters A-Z
|| (Character.toUpperCase(employeeNumber.charAt(4)) > 'M'))
{
status = false; //status is false if conditions don't meet
}
return status; //returns if the employee number is valid (true for valid)
}
//Returns a string value holding informatino about the employee
public String toString()
{
String str = "Name: " + name + "\nEmployee Number: "; //sets str equal to the employee's name
if (employeeNumber == "") //employee must have a valid number, if they have a blank number, it is invalid
str += "INVALID EMPLOYEE NUMBER";
else //concatenate str with the employee's number
str += employeeNumber;
str += ("\nHire Date: " + hireDate); //concatenate the str with the employee's hire date
return str; //return str
}
//////////////////////////////////////////////////GUI///////////////////////////////////
////////Show Info////////
private JPanel showInfoPanel;
private JTextArea employeeInformation;
public void buildPanel()
{
showInfoPanel = new JPanel();
employeeInformation = new JTextArea(this.toString(), 10, 50);
showInfoPanel.add(employeeInformation);
}
public JPanel getInfoPanel()
{
this.buildPanel();
return showInfoPanel;
}
}
ProductionWorker Class
/*******************************************************************************
* Program Name: ProductionWorker.java
* Created Date: 1/31/2016
* Created By: Tommy Saechao
* Purpose: A subclass that inherits information from the Employee superclass.
* This subclass contains information about a production worker.
*******************************************************************************/
package pkg10.pkg1.employee.and.productionworker.classes;
import java.text.DecimalFormat;
//subclass of Employee
public class ProductionWorker extends Employee{
//Day Shift value is 1, Night shift value is 2
public static final int DAY_SHIFT = 1;
public static final int NIGHT_SHIFT = 2;
private int shift; //holds the shift value
private double hourlyPayRate; //holds the hourly pay rate
//default constructor
ProductionWorker()
{
super(); //calls the default super class constructor
//Employee's name, employeeNumber, and hireDate will be blank ("")
shift = DAY_SHIFT; //default shift is day shift
hourlyPayRate = 0.0; //default pay is zero
}
//constructor
ProductionWorker(String name, String employeeNumber, String hireDate, int shift, int hourlyPayRate)
{
super(name, employeeNumber, hireDate); //calls superclass constructor
//Employee's name, emloyee number, and hire date will be set equal to
//name, employeeNumber, and hireDate from this constructor's givevn arguments
this.shift = shift; //sets shift value
this.hourlyPayRate = hourlyPayRate; //sets employee's hourly pay rate value
}
//sets shift
public void setShift (int shift)
{
this.shift = shift;
}
//sets pay rate
public void setPayRate (double hourlyPayRate)
{
this.hourlyPayRate = hourlyPayRate;
}
//returns shift number
public int getShift()
{
return shift;
}
//returns pay rate
public double getPayRate()
{
return hourlyPayRate;
}
//provides information about a production worker
public String toString()
{
//formats a double value to appear as the dollar format
DecimalFormat dollar = new DecimalFormat("#,##0.00");
/*calls superclass' toString method, which gives str information about the employee's
name, employee number, and hire date*/
String str = super.toString();
//adds shift time to str
str += "\nShift: ";
if (shift == DAY_SHIFT)
str += "Day";
else if (shift == NIGHT_SHIFT)
str += "Night";
else
//the employee doesn't have a valid shift number (valid is DAY_SHIFT (1) and NIGHT_SHIFT (2) )
str += "INVALID SHIFT NUMBER";
//adds hourly pay rate information to str
str += ("\nHourly Pay Rate: $" + dollar.format(hourlyPayRate));
return str; //returns str
}
}
答案 0 :(得分：3)
如果要更新文本区域（或任何Swing组件），则需要对组件的引用。
因此，您需要将变量定义为类中的实例变量。然后，您可以直接在该类中更新变量，或者您需要为可以从ActionListener访问的该类创建updateTextArea(...)方法。
查看How to Write a Mouse Listener上Swing教程中的部分。这里的演示代码显示了如何构建代码的示例，以便您可以从侦听器更新文本区域。它应该让你更好地了解如何设计你的课程。
答案 1 :(得分：0)
如果您想设置JTextArea使用textArea.setText("My Text");
如果您想在现有文字中添加更多文字，请使用textArea.append("Text To Add");
只需在按钮ActionListener中放置您想要使用的那个，就可以了。