Java 如何将ActionPerformed从ActionListener发送到另一个ActionListener?
我有一个框架(这里称为“MainApplication”),它主要有一个JPanel来显示信息,具体取决于上下文 启动时,Main应用程序有一个空的JPanel 然后,它创建一个“LoginRequest”类,该类创建一个简单的登录/密码表单,并将其发送回main应用程序,main应用程序将其显示在其JPanel中 “LoginRequest”类实现ActionListener,因此当用户单击“Login”按钮时,它会检查登录/密码是否正确,如果用户被授权,我希望卸载该表单,并在主应用程序框架上显示主屏幕 因此,为了做到这一点,我提出了以下建议:Java 如何将ActionPerformed从ActionListener发送到另一个ActionListener?,java,swing,actionlistener,Java,Swing,Actionlistener,我有一个框架(这里称为“MainApplication”),它主要有一个JPanel来显示信息,具体取决于上下文 启动时,Main应用程序有一个空的JPanel 然后,它创建一个“LoginRequest”类,该类创建一个简单的登录/密码表单,并将其发送回main应用程序,main应用程序将其显示在其JPanel中 “LoginRequest”类实现ActionListener,因此当用户单击“Login”按钮时,它会检查登录/密码是否正确,如果用户被授权,我希望卸载该表单,并在主应用程序框架上
public class LoginRequest implements ActionListener {
protected MainApplication owner_m = null;
public LoginRequest(MainApplication owner_p) {
owner_m = owner_p;
}
@Override
public void actionPerformed(ActionEvent event_p) {
// the user just clicked the "Login" button
if (event_p.getActionCommand().equals("RequestLogin")) {
// check if login/password are correct
if (getParameters().isUserGranted(login_l, password_l)) {
// send an ActionEvent to the "MainApplication", so as it will
// be notified to display the next screen
this.owner_m.actionPerformed(
new java.awt.event.ActionEvent(this, 0, "ShowSummary")
);
} else {
messageLabel_m.setForeground(Color.RED);
messageLabel_m.setText("Incorrect user or password");
}
}
}
}
然后,“MainApplication”类(扩展了JFrame):
当ActionEvent从“LoginRequest”类发送到“MainApplication”类时,它会执行代码,但最后什么都没有发生,就好像JFrame没有重新绘制一样
有什么想法吗
谢谢,最好的方法是使用
JDialog
(主框架JFrame
将是父组件)作为登录表单,并使用CardLayout
在面板之间切换(因此无需移除、重新绘制和重新验证):
您的主窗体应该如下所示:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MainFrame{
JFrame frame = new JFrame("Main frame");
JPanel welcomePanel = new JPanel();
JPanel workspacePanel = new JPanel();
JPanel cardPanel = new JPanel();
JButton btnLogin = new JButton("Login");
JLabel lblWelcome = new JLabel("Welcome to workspace");
CardLayout cl = new CardLayout();
LoginRequest lr = new LoginRequest(this);
public MainFrame() {
welcomePanel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
lr.setVisible(true);
}
});
workspacePanel.add(lblWelcome);
cardPanel.setLayout(cl);
cardPanel.add(welcomePanel, "1");
cardPanel.add(workspacePanel, "2");
cl.show(cardPanel,"1");
frame.getContentPane().add(cardPanel);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setPreferredSize(new Dimension(320,240));
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String [] args){
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new MainFrame();
}
});
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class LoginRequest extends JDialog{
/**You can add, JTextFields, JLabel, JPasswordField..**/
JPanel panel = new JPanel();
JButton btnLogin = new JButton("Login");
public LoginRequest(final MainFrame mf) {
setTitle("Login");
panel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
//Put some login logic here
mf.cl.show(mf.cardPanel,"2");
dispose();
}
});
add(panel, BorderLayout.CENTER);
setModalityType(ModalityType.APPLICATION_MODAL);
setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
pack();
setLocationByPlatform(true);
}
}
您的登录表单应如下所示:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MainFrame{
JFrame frame = new JFrame("Main frame");
JPanel welcomePanel = new JPanel();
JPanel workspacePanel = new JPanel();
JPanel cardPanel = new JPanel();
JButton btnLogin = new JButton("Login");
JLabel lblWelcome = new JLabel("Welcome to workspace");
CardLayout cl = new CardLayout();
LoginRequest lr = new LoginRequest(this);
public MainFrame() {
welcomePanel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
lr.setVisible(true);
}
});
workspacePanel.add(lblWelcome);
cardPanel.setLayout(cl);
cardPanel.add(welcomePanel, "1");
cardPanel.add(workspacePanel, "2");
cl.show(cardPanel,"1");
frame.getContentPane().add(cardPanel);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setPreferredSize(new Dimension(320,240));
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String [] args){
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new MainFrame();
}
});
}
}
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class LoginRequest extends JDialog{
/**You can add, JTextFields, JLabel, JPasswordField..**/
JPanel panel = new JPanel();
JButton btnLogin = new JButton("Login");
public LoginRequest(final MainFrame mf) {
setTitle("Login");
panel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
//Put some login logic here
mf.cl.show(mf.cardPanel,"2");
dispose();
}
});
add(panel, BorderLayout.CENTER);
setModalityType(ModalityType.APPLICATION_MODAL);
setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
pack();
setLocationByPlatform(true);
}
}
编辑:
你的方式:
大型机类:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class MainFrame{
JFrame frame = new JFrame("Main frame");
JPanel welcomePanel = new JPanel();
JPanel workspacePanel = new JPanel();
JPanel cardPanel = new JPanel();
JButton btnLogin = new JButton("Login");
JLabel lblWelcome = new JLabel("Welcome");
LoginRequest lr = new LoginRequest(this);
public MainFrame() {
welcomePanel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
lr.setVisible(true);
}
});
workspacePanel.add(lblWelcome);
frame.getContentPane().add(welcomePanel);
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setPreferredSize(new Dimension(320,240));
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String [] args){
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new MainFrame();
}
});
}
}
登录请求类:
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class LoginRequest extends JDialog{
/**You can add, JTextFields, JLabel, JPasswordField..**/
JPanel panel = new JPanel();
JButton btnLogin = new JButton("Login");
public LoginRequest(final MainFrame mf) {
setTitle("Login");
panel.add(btnLogin);
btnLogin.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
//Put some login logic here
mf.frame.getContentPane().removeAll();
mf.frame.add(mf.workspacePanel);
mf.frame.repaint();
mf.frame.revalidate();
dispose();
}
});
add(panel, BorderLayout.CENTER);
setModalityType(ModalityType.APPLICATION_MODAL);
setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
pack();
setLocationByPlatform(true);
}
}
调用
LoginRequest
类中的actionPerformed
方法中的repaint
和revalidate
方法。比如:owner_m.repaint();所有者重新验证();为什么不使用模式对话框来收集凭据?@brano88:我已经尝试过了,但它没有改变任何东西…:(@trashgood:是的,你是对的,我可以这么做,但我还是想知道为什么我写的代码不起作用:/谢谢你的完整回答。我会选择卡片布局,尽管有一些修改,因为我的面板“懒惰”(它们在“主应用程序”要求之前没有自行构建)。顺便说一句,我仍然不明白为什么我的第一个代码不起作用…删除/重新绘制/重新验证面板可能不是最好的方法,但它应该起作用…:/你正在尝试在MainApplication类中触发一个事件,但你正在LoginRequest中的actionPerformed
方法中传递这个代码>类。尝试传递owner\m
@adrien。痛苦:作为参考,这里有一个使用validate()
的工作,但是CardLayout
(+1)更好。@brano88:谢谢你的建议,但是我可以将“LoginRequest”对象传递给“main应用程序”,即使在执行的操作中也是如此。(我使用它来知道该操作的调用方是什么).它现在起作用了