Java事件侦听器代码未按预期运行(初学者)
因此,我现在更新了代码:但它仍然没有将字符串设置为输入Java事件侦听器代码未按预期运行(初学者),java,swing,event-handling,windowlistener,Java,Swing,Event Handling,Windowlistener,因此,我现在更新了代码:但它仍然没有将字符串设置为输入 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; public class Funclass extends JFrame implements WindowListener { FlowLayout layout = new FlowLayout(); String[] Skillz
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class Funclass extends JFrame implements WindowListener {
FlowLayout layout = new FlowLayout();
String[] Skillz = {"Analytical", "Numerical", "Leadership",
"Communication", "Organisation", "Interpersonal"};
String[] ROLEZ = {"Developer", "Sales", "Marketing", "Consultant"};
String[] Industries = {"Consulting", "Tech"};
public String R1, R2, R3, R4, RETURNROLE,
RETURNTYPE, RETURNLIST, RETURNCOMPANY;
JTextField Company = new JTextField("Company Name");
JComboBox TYPE = new JComboBox(Industries);
JList Skills = new JList(Skillz);
JComboBox ROLE = new JComboBox(ROLEZ);
JButton Submit = new JButton("Submit");
public Funclass() {
super("Input Interface");
setLayout(layout);
Skills.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
add(Company);
add(TYPE);
add(ROLE);
add(Skills);
Company.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent event) {
if (event.getSource() == Company);
RETURNCOMPANY = event.getActionCommand();
}
});
Skills.addListSelectionListener(
new ListSelectionListener() {
public void valueChanged(ListSelectionEvent event) {
RETURNLIST = (String) Skills.getSelectedValue();
}
});
TYPE.addItemListener(
new ItemListener() {
public void itemStateChanged(ItemEvent event) {
if (event.getStateChange() == ItemEvent.SELECTED) {
RETURNTYPE = Industries[TYPE.getSelectedIndex()];
}
}
});
ROLE.addItemListener(
new ItemListener() {
public void itemStateChanged(ItemEvent event) {
if (event.getStateChange() == ItemEvent.SELECTED) {
RETURNROLE = ROLEZ[ROLE.getSelectedIndex()];
}
}
});
}
public void windowClosed(WindowEvent e) {
CreateCoverLetter creatorObject = new CreateCoverLetter();
creatorObject.openFile();
creatorObject.addBody(RETURNCOMPANY, RETURNROLE, RETURNLIST);
creatorObject.closeFile();
System.out.println(RETURNCOMPANY);
}
public void windowDeiconified(WindowEvent e) {}
public void windowActivated(WindowEvent e) {}
public void windowClosing(WindowEvent e) {}
public void windowDe(WindowEvent e) {}
public void windowIconified(WindowEvent e) {}
public void windowDeactivated(WindowEvent e) {}
public void windowOpened(WindowEvent e) {}
}
我是一个完全的初学者,我试图构建一个简单的程序,从一个基本的GUI获取用户输入并使用它们创建一个文件。出于某种原因,当我运行此程序时,代码会执行,但字符串变量RETURNROLE
,RETURNLIST
,RETURNCOMPANY
没有设置为用户输入的值。有人能解释为什么吗
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.*;
import javax.swing.event.*;
public class Funclass extends JFrame{
FlowLayout layout = new FlowLayout();
String[] Skillz = {"Analytical", "Numerical", "Leadership", "Communication", "Organisation", "Interpersonal"};
String[] ROLEZ = {"Developer", "Sales", "Marketing", "Consultant"};
String[] Industries = {"Consulting", "Tech"};
public String R1, R2, R3, R4, RETURNROLE, RETURNTYPE, RETURNLIST, RETURNCOMPANY;
JTextField Company = new JTextField("Company Name");
JComboBox TYPE = new JComboBox(Industries);
JList Skills = new JList(Skillz);
JComboBox ROLE = new JComboBox(ROLEZ);
public Funclass(){
super("Input Interface");
setLayout(layout);
Skills.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
add(Company);
add(TYPE);
add(ROLE);
add(Skills);
Company.addActionListener(
new ActionListener(){
public void actionPerformed(ActionEvent event){
if(event.getSource()==Company);
RETURNCOMPANY = event.getActionCommand();
}
}
);
Skills.addListSelectionListener(
new ListSelectionListener(){
public void valueChanged(ListSelectionEvent event){
RETURNLIST = (String) Skills.getSelectedValue();
}
});
TYPE.addItemListener(
new ItemListener(){
public void itemStateChanged(ItemEvent event){
if(event.getStateChange()==ItemEvent.SELECTED)
RETURNTYPE = Industries[TYPE.getSelectedIndex()];
}
}
);
ROLE.addItemListener(
new ItemListener(){
public void itemStateChanged(ItemEvent event){
if(event.getStateChange()==ItemEvent.SELECTED)
RETURNROLE = ROLEZ[ROLE.getSelectedIndex()];
}
}
);
CreateCoverLetter creatorObject = new CreateCoverLetter();
creatorObject.openFile();
creatorObject.addBody(RETURNCOMPANY, RETURNROLE, RETURNLIST);
creatorObject.closeFile();
System.out.println(RETURNCOMPANY);
}
}
您正在类的构造函数中创建输出文件,因此该文件是在用户有机会填写或选择任何值之前创建的
我会添加一个Submit按钮或其他东西,然后让它提取UI元素的内容并创建文件。您不需要所有不同的侦听器,因为您可以在提交按钮上读取ActionEvent时的值 您正在类的构造函数中创建输出文件,因此该文件是在用户有机会填写或选择任何值之前创建的
我会添加一个Submit按钮或其他东西,然后让它提取UI元素的内容并创建文件。您不需要所有不同的侦听器,因为您可以在提交按钮上读取ActionEvent时的值 之所以会发生这种情况,是因为您正在构造函数中写入文件,在定义侦听器之后,在触发任何将为这些变量赋值的事件之前 例如,您可以在用户关闭窗口时写入文件,方法是让类实现
WindowListener
,然后实现windowClosed
事件:
public class Funclass extends JFrame implements WindowListener {
// ...
public void windowClosed(WindowEvent e) {
CreateCoverLetter creatorObject = new CreateCoverLetter();
creatorObject.openFile();
creatorObject.addBody(RETURNCOMPANY, RETURNROLE, RETURNLIST);
creatorObject.closeFile();
System.out.println(RETURNCOMPANY);
}
}
发生这种情况的原因是,在定义监听器之后,在触发任何将为这些变量赋值的事件之前,您正在构造函数中写入文件 例如,您可以在用户关闭窗口时写入文件,方法是让类实现
WindowListener
,然后实现windowClosed
事件:
public class Funclass extends JFrame implements WindowListener {
// ...
public void windowClosed(WindowEvent e) {
CreateCoverLetter creatorObject = new CreateCoverLetter();
creatorObject.openFile();
creatorObject.addBody(RETURNCOMPANY, RETURNROLE, RETURNLIST);
creatorObject.closeFile();
System.out.println(RETURNCOMPANY);
}
}
添加了
Company
的ActionListener()
如果您想监听到的某些更改
JTextField Company = new JTextField("Company Name");
然后您必须实现,示例添加了
Company
的一些错误ActionListener()
如果您想监听到的某些更改
JTextField Company = new JTextField("Company Name");
然后,您必须执行示例您是否确定事件正在发生?如果这些事件没有发生,那么这些变量中就永远不会有您希望了解的值。在java中,ALCAP通常指示常量值,这使得代码看起来很奇怪。考虑使用“代替代码”>实现Windows WistList< <代码>。您确定事件是否正在发生?如果这些事件没有发生,那么这些变量中就永远不会有您希望了解的值。ALCAP通常在java中指示常量值,这使得代码看起来很奇怪。考虑使用“代替代码”>实现Windows WisteleNo//Cux.@ Ravin:这个答案(1 +)给出了事件驱动编程的本质。对于这种类型的程序,您不能以线性方式思考,而必须对事件做出响应。@Ravin:这个答案(1+)为您提供了事件驱动编程的本质。对于这种类型的程序,您不能以线性方式思考,但必须响应事件。如果我这样做,我是否必须在主方法中调用windowCLosed方法,如果是,我应该传递什么参数?如果这样做,您将在窗口关闭后立即写入文件,即。,关闭窗口时会自动调用该方法。如果这样做,我是否必须在主方法中调用windowCLosed方法,如果是,我应该传递什么参数?如果这样做,您将在窗口关闭后立即写入文件,即关闭窗口时会自动调用该方法。