AWT窗口关闭侦听器/事件 [英] AWT Window Close Listener/Event

问题描述

如果这是一个n00b的问题，我很抱歉，但是，一旦我创建了Window侦听器，窗口事件和其他所有内容，我已经花费了太多的时间了，我该如何指定什么方法调用？这是我的代码：

I am sorry if this is a n00b question, but I have spent way too long for this once I create the Window listener, window event, and everything else, how do I specify what method to invoke? Here is my code:

private static void mw() {
    Frame frm = new Frame("Hello Java");
    WindowEvent we = new WindowEvent(frm, WindowEvent.WINDOW_CLOSED);
    WindowListener wl = null;
    wl.windowClosed(we);
    frm.addWindowListener(wl);
    TextField tf = new TextField(80);
    frm.add(tf);
    frm.pack();
    frm.setVisible(true);

}

我正在尝试获取一个URL，并下载它，我已经做了一切工作，我只是想让窗口关闭。

I am trying to get a URL, and Download it, I have everything else worked out, I am just trying to get the window to close.

推荐答案

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class FrameByeBye {

    // The method we wish to call on exit.
    public static void showDialog(Component c) {
        JOptionPane.showMessageDialog(c, "Bye Bye!");
    }

    public static void main(String[] args) {
        // creating/udpating Swing GUIs must be done on the EDT.
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {

                final JFrame f = new JFrame("Say Bye Bye!");
                // Swing's default behavior for JFrames is to hide them.
                f.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
                f.addWindowListener( new WindowAdapter() {
                    @Override
                    public void windowClosing(WindowEvent we) {
                        showDialog(f);
                        System.exit(0);
                    }
                } );
                f.setSize(300,200);
                f.setLocationByPlatform(true);
                f.setVisible(true);

            }
        });
    }
}

---

另外查看 Runtime.addShutdownHook（Thread） 对于在关闭之前执行至关重要的任何操作。

---

Also look into Runtime.addShutdownHook(Thread) for any action that is vital to perform before shutting down.

..产生不依赖于在系统上安装JVM / JRE以执行

..produce "Native" executables that do not depend on the JVM/JRE installed on the system to function"

更好的选择是：

1. 使用Swing创建富客户端。


2. 使用 deployJava.js 来检查用户具有适当的JRE。


3. 使用 Java Web Start 安装并启动应用程序（并在需要时从网上更新）。

1. Use Swing to create the rich client.
2. Use deployJava.js to check the user has an appropriate JRE.
3. Use Java Web Start to install and launch the app. (and update it when needed) direct from the net.

---

<因为你提到小程序和下载请注意，只有受信任的小程序/应用程序JWS。可以跨域获取数据，它将采用相同的信任版本将文件保存到本地文件系统，也可以使用JWS&使用JNLP API文件服务。

---

And since you mention 'applet' and 'download' note that only a trusted applet/JWS app. can get data across domains, and it would take either a trusted version of same to save files to the local file system, or being deployed using JWS & using the JNLP API file services.

一旦你有一个富客户端应用程序。使用JWS启动 - 小程序可能变得无关紧要。

Once you have a rich client app. launched using JWS - the applet might become irrelevant.

OK - 我输入，这是代码的AWT版本。

OK - I give in. Here is an AWT version of that code.

import java.awt.*;
import java.awt.event.*;

class FrameByeBye {

    // The method we wish to call on exit.
    public static void showMessage() {
        System.out.println("Bye Bye!");
    }

    public static void main(String[] args) {
        Frame f = new Frame("Say Bye Bye!");
        f.addWindowListener( new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent we) {
                showMessage();
                System.exit(0);
            }
        } );
        f.setSize(300,200);
        f.setLocationByPlatform(true);
        f.setVisible(true);
    }
}

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