关闭一个JFrame,然后再打开另一个JFrame [英] Close one JFrame before opening another JFrame
问题描述
我想在打开另一个 JFrame
之前完全关闭它.
I want to close completely one JFrame
before opening another .
考虑代码:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.InetAddress;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
/**
*
* @author X
*
*/
class ServerConnect extends JFrame implements ActionListener
{
private static final long serialVersionUID = 1L;
private JTextField m_serverIP;
private JTextField m_serverPort; // you can use also JPasswordField
private JButton m_submitButton;
// location of the jframe
private final int m_centerX = 500;
private final int m_centerY = 300;
// dimensions of the jframe
private final int m_sizeX = 1650;
private final int m_sizeY = 150;
/**
* Ctor
*/
ServerConnect()
{
this.setTitle("Sever Side Listener");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
m_serverIP = new JTextField(20);
m_serverPort = new JTextField(20);
JPanel gui = new JPanel(new BorderLayout(3,3));
gui.setBorder(new EmptyBorder(5,5,5,5));
gui.setSize(m_sizeX , m_sizeY);
this.setContentPane(gui);
JPanel labels = new JPanel(new GridLayout(0,1));
JPanel controls = new JPanel(new GridLayout(0,1));
gui.add(labels, BorderLayout.WEST);
gui.add(controls, BorderLayout.CENTER);
labels.add(new JLabel("Server IP: "));
controls.add(m_serverIP);
labels.add(new JLabel("Server Port: "));
controls.add(m_serverPort);
m_submitButton = new JButton("Start Listening");
m_submitButton.addActionListener(this);
gui.add(m_submitButton, BorderLayout.SOUTH);
this.setLocation(m_centerX , m_centerY);
this.setSize(m_sizeX , m_sizeY);
this.pack();
this.setVisible(true);
}
public static void main(String[] args) {
new ServerConnect();
}
@Override
public void actionPerformed(ActionEvent event) {
Object object = event.getSource();
if (object == this.m_submitButton)
{
// grab all values from the connection box
// if one of them is missing then display an alert message
String ip = this.m_serverIP.getText().trim();
String port = this.m_serverPort.getText().trim();
if (ip.length() == 0)
{
JOptionPane.showMessageDialog(null, "Please enter IP address !");
return;
}
if (port.length() == 0)
{
JOptionPane.showMessageDialog(null, "Please enter Port number!");
return;
}
int s_port = 0;
try
{
// try parse the Port number
// throws exception when an incorrect IP address
// is entered , and caught in the catch block
s_port = Integer.parseInt(port);
}
catch(Exception exp)
{
JOptionPane.showMessageDialog(null, "Port number is incorrect!");
return;
}
try
{
// try parse the IP address
// throws exception when an incorrect IP address
// is entered , and caught in the catch block
InetAddress.getByName(ip);
}
catch(Exception exp)
{
JOptionPane.showMessageDialog(null, "IP address is incorrect!");
return;
}
this.setVisible(false);
new ServerGUI(ip , s_port);
}
}
}
在用户输入IP地址和端口后的 actionPerformed()
中,我将窗口设置为false,即:
In actionPerformed()
after the user had entered the IP number and port , I set the window to false , i.e :
this.setVisible(false); // don't show the current window
new ServerGUI(ip , s_port); // open another JFrame
我想完全关闭当前的 JFrame
,而不是将其可见性设置为false.
I want to close the current JFrame
completely, not to set its visibility to false.
我该怎么做?
致谢
推荐答案
您的问题似乎是,如果您在JFrame上调用close,则该程序将退出,因为您已将其setDefaultCloseOperation设置为 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
.
Your problem appears that if you call close on the JFrame, the program will exit since you've set its setDefaultCloseOperation to setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
.
选项:
- 使用不同的defaultCloseOperation,它不会关闭应用程序,可能是
JFrame.DISPOSE_ON_CLOSE
. - 最初使用JDialog而不是JFrame.这些类型的Windows 无法关闭应用程序.这是 JDialog和JOptionPane教程
- 根本不交换JFrame,而是使用CardLayout交换 视图 . CardLayout教程链接
- Use a different defaultCloseOperation, one that doesn't close the application, perhaps
JFrame.DISPOSE_ON_CLOSE
. - Use a JDialog initially instead of a JFrame. These types of windows can't shut down the application. Here is the JDialog and JOptionPane Tutorial
- Don't swap JFrames at all, but rather swap views by using a CardLayout. The CardLayout Tutorial link
我个人的喜好是尽可能使用CardLayout以避免惹恼通常不喜欢一堆窗户向他扑来的用户.当我想以模态方式从用户那里获取信息时,我也使用模态JDialogs,即在用户提供所请求的信息之前,应用程序绝对无法前进,而非模态对话框则为用户提供程序状态监视信息.我几乎从来没有在单个应用程序中使用多个JFrame.
My own preference is to use a CardLayout as much as possible to avoid annoying the user who usually doesn't appreciate having a bunch of windows flung at him. I also use modal JDialogs when I want to get information from the user in a modal fashion, i.e., where the application absolutely cannot move forward until the user gives the requested information, and non-modal dialogs to present program state monitoring information for the user. I almost never use multiple JFrames in a single application.
修改
顺便说一句,我几乎从不创建扩展JFrame或任何顶级窗口的类,因为我发现限制太多了.取而代之的是,我的大多数GUI类型类都旨在创建JPanels.这样的好处是,我可以决定何时和在何处放置JPanel,并且可以随时改变主意.它可以放入JFrame,JDialog,JOptionPane,成为可在CardLayout中交换的卡,...在任何地方.
Edit
As an aside, I almost never create classes that extend JFrame or any top-level window since I find that much too restricting. Instead most of my GUI type classes are geared towards creating JPanels. The advantage to this is then I can decide when and where I want to put the JPanel, and can change my mind at any time. It could go into a JFrame, a JDialog, a JOptionPane, be a card that is swapped in a CardLayout,... anywhere.
编辑2
例如,这是一个小程序,它使用您的代码,对其进行了稍微修改,然后将其放入JDialog:
For example, here's a small program that uses your code, slightly modified, and puts it into a JDialog:
我的代码:
import java.awt.Dialog.ModalityType;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.*;
public class MyServerMain extends JPanel {
private JTextField serverIp = new JTextField(8);
private JTextField serverPort = new JTextField(8);
private ServerConnect serverConnect = new ServerConnect();
private JDialog serverConnectDialog = null;
public MyServerMain() {
serverIp.setFocusable(false);
serverPort.setFocusable(false);
add(new JLabel("Server IP:"));
add(serverIp);
add(new JLabel("Server Port:"));
add(serverPort);
add(new JButton(new SetUpServerAction("Set Up Server", KeyEvent.VK_S)));
}
private class SetUpServerAction extends AbstractAction {
public SetUpServerAction(String name, int keyCode) {
super(name);
putValue(MNEMONIC_KEY, keyCode);
}
@Override
public void actionPerformed(ActionEvent evt) {
if (serverConnectDialog == null) {
Window owner = SwingUtilities.getWindowAncestor(MyServerMain.this);
serverConnectDialog = new JDialog(owner, "Server Set Up",
ModalityType.APPLICATION_MODAL);
serverConnectDialog.getContentPane().add(serverConnect);
serverConnectDialog.pack();
serverConnectDialog.setLocationRelativeTo(owner);
}
serverConnectDialog.setVisible(true);
// when here, the dialog is no longer visible
// so extract information from the serverConnect object
serverIp.setText(serverConnect.getServerIp());
serverPort.setText(serverConnect.getServerPort());
}
}
private static void createAndShowGui() {
MyServerMain mainPanel = new MyServerMain();
JFrame frame = new JFrame("My Server Main");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
您修改的代码:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.InetAddress;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
class ServerConnect extends JPanel implements ActionListener {
private static final long serialVersionUID = 1L;
private JTextField m_serverIP;
private JTextField m_serverPort; // you can use also JPasswordField
private JButton m_submitButton;
// location of the jframe
private final int m_centerX = 500;
private final int m_centerY = 300;
// dimensions of the jframe
private final int m_sizeX = 1650;
private final int m_sizeY = 150;
ServerConnect() {
m_serverIP = new JTextField(20);
m_serverPort = new JTextField(20);
JPanel gui = new JPanel(new BorderLayout(3, 3));
gui.setBorder(new EmptyBorder(5, 5, 5, 5));
gui.setSize(m_sizeX, m_sizeY);
setLayout(new BorderLayout()); // !!
add(gui, BorderLayout.CENTER);
JPanel labels = new JPanel(new GridLayout(0, 1));
JPanel controls = new JPanel(new GridLayout(0, 1));
gui.add(labels, BorderLayout.WEST);
gui.add(controls, BorderLayout.CENTER);
labels.add(new JLabel("Server IP: "));
controls.add(m_serverIP);
labels.add(new JLabel("Server Port: "));
controls.add(m_serverPort);
m_submitButton = new JButton("Start Listening");
m_submitButton.addActionListener(this);
gui.add(m_submitButton, BorderLayout.SOUTH);
this.setLocation(m_centerX, m_centerY);
this.setSize(m_sizeX, m_sizeY);
// !! this.pack();
// !! this.setVisible(true);
}
public static void main(String[] args) {
new ServerConnect();
}
@Override
public void actionPerformed(ActionEvent event) {
Object object = event.getSource();
if (object == this.m_submitButton) {
// grab all values from the connection box
// if one of them is missing then display an alert message
String ip = this.m_serverIP.getText().trim();
String port = this.m_serverPort.getText().trim();
if (ip.length() == 0) {
JOptionPane.showMessageDialog(null, "Please enter IP address !");
return;
}
if (port.length() == 0) {
JOptionPane.showMessageDialog(null, "Please enter Port number!");
return;
}
int s_port = 0;
try {
// try parse the Port number
// throws exception when an incorrect IP address
// is entered , and caught in the catch block
s_port = Integer.parseInt(port);
}
catch (Exception exp) {
JOptionPane.showMessageDialog(null, "Port number is incorrect!");
return;
}
try {
// try parse the IP address
// throws exception when an incorrect IP address
// is entered , and caught in the catch block
InetAddress.getByName(ip);
}
catch (Exception exp) {
JOptionPane.showMessageDialog(null, "IP address is incorrect!");
return;
}
// !! this.setVisible(false);
// !! new ServerGUI(ip , s_port);
// !!
Window ownerWindow = SwingUtilities.getWindowAncestor(this);
ownerWindow.dispose();
}
}
// !!
public String getServerIp() {
return m_serverIP.getText();
}
// !!
public String getServerPort() {
return m_serverPort.getText();
}
}
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