java中如何处理JFrame窗口事件？
这个例子告诉你如何处理JFrame窗口事件，如windowOpened，windowClosing，windowClosed，等处理这些事件，我们需要一个添加WindowListener监听器JFrame实例。在这里，我们使用WindowAdapter抽象类并实现要处理的事件的方法。
package org.nhooo.example.swing;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class WindowListenerDemo extends JFrame {
public WindowListenerDemo() {
initializeComponent();
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new WindowListenerDemo().setVisible(true));
}
private void initializeComponent() {
setSize(300, 300);
setTitle("Window Listener");
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
this.addWindowListener(new WindowAdapter() {
//打开窗口时调用。
public void windowOpened(WindowEvent e) {
System.out.println("Window Opened Event");
}
//在关闭窗口的过程中调用。
//此时关闭操作可以被覆盖。
public void windowClosing(WindowEvent e) {
System.out.println("Window Closing Event");
}
//窗口关闭时调用。
public void windowClosed(WindowEvent e) {
System.out.println("Window Close Event");
}
//当窗口被图标化时调用。
public void windowIconified(WindowEvent e) {
System.out.println("Window Iconified Event");
}
//取消图标化窗口时调用。
public void windowDeiconified(WindowEvent e) {
System.out.println("Window Deiconified Event");
}
//激活窗口时调用。
public void windowActivated(WindowEvent e) {
System.out.println("Window Activated Event");
}
//禁用窗口时调用。
public void windowDeactivated(WindowEvent e) {
System.out.println("Window Deactivated Event");
}
//更改窗口状态时调用。
public void windowStateChanged(WindowEvent e) {
System.out.println("Window State Changed Event");
}
//当“窗口”设置为焦点窗口时调用，这意味着
//窗口或其子组件之一将接收键盘
//事件。
public void windowGainedFocus(WindowEvent e) {
System.out.println("Window Gained Focus Event");
}
//当窗口不再是焦点窗口时调用
//该键盘事件将不再传递到窗口或任何
//它的子组件。
public void windowLostFocus(WindowEvent e) {
System.out.println("Window Lost Focus Event");
}
});
}
}