Question

所有

我有一个JPanel说JTabbedPane的容器，它包含一个设计和一个预览面板。

JPanel位于JFrame中，

预览面板包含JME3画布。

我想要实现的目标，每当用户移动到应用程序中的另一个面板时，我都可以捕获容器Jpanel的卸载并关闭JME3应用程序，

我找到了以下帖子，

Similar Threads 1

Similar Thread 2

我通过这些线程了解到HierarchyListener可能对我有用，但我被困在如何在那里得到特定的面板卸载检测？

由于米希尔

Answer 1

有三个侦听器对这些事件做出反应AncestorListener，ComponentListener，HierarchyListener
默认使用ComponentListener

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.HierarchyEvent;
import java.awt.event.HierarchyListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.event.AncestorEvent;
import javax.swing.event.AncestorListener;

public class CardlayoutTest extends JFrame {

    private static final long serialVersionUID = 1L;
    public CardLayout card = new CardLayout();

    public CardlayoutTest() {
        JPanel pnlA = new JPanel(new BorderLayout());
        pnlA.add(new JButton("A"), BorderLayout.CENTER);
        JPanel pnlB = new JPanel(new BorderLayout());
        pnlB.add(new JButton("B"), BorderLayout.CENTER);
        JPanel pnlC = new JPanel(new BorderLayout());
        pnlC.add(new JButton("C"), BorderLayout.CENTER);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLayout(card);
        add(pnlA, "A");
        add(pnlB, "B");
        add(pnlC, "C");

        pnlA.addAncestorListener(new EventHandler());
        pnlB.addAncestorListener(new EventHandler());
        pnlC.addAncestorListener(new EventHandler());

        pnlA.addHierarchyListener(new EventHandler());
        pnlB.addHierarchyListener(new EventHandler());
        pnlB.addHierarchyListener(new EventHandler());

        pnlA.addComponentListener(new EventHandler());
        pnlB.addComponentListener(new EventHandler());
        pnlB.addComponentListener(new EventHandler());
    }

    class EventHandler implements AncestorListener, ComponentListener, HierarchyListener {

        @Override
        public void ancestorAdded(AncestorEvent event) {
            System.out.println("CardlayoutTest.EventHandler.ancestorAdded()");
        }

        @Override
        public void ancestorMoved(AncestorEvent event) {
            System.out.println("CardlayoutTest.EventHandler.ancestorMoved()");
        }

        @Override
        public void ancestorRemoved(AncestorEvent event) {
            System.out.println("CardlayoutTest.EventHandler.ancestorRemoved()");
        }

        @Override
        public void hierarchyChanged(HierarchyEvent e) {
            System.out.println("Components Change: " + e.getChanged());
            if ((e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0) {
                if (e.getComponent().isDisplayable()) {
                    System.out.println("Components DISPLAYABILITY_CHANGED : " + e.getChanged());
                } else {
                    System.out.println("Components DISPLAYABILITY_CHANGED : " + e.getChanged());
                }
            }
            if ((e.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) != 0) {
                if (e.getComponent().isDisplayable()) {
                    System.out.println("Components SHOWING_CHANGED : " + e.getChanged());
                } else {
                    System.out.println("Components SHOWING_CHANGED : " + e.getChanged());
                }
            }
        }

        public void componentHidden(ComponentEvent e) {
            System.out.println(e.getComponent().getClass().getName() + " --- Hidden");
        }

        public void componentMoved(ComponentEvent e) {
            System.out.println(e.getComponent().getClass().getName() + " --- Moved");
        }

        public void componentResized(ComponentEvent e) {
            System.out.println(e.getComponent().getClass().getName() + " --- Resized ");
        }

        public void componentShown(ComponentEvent e) {
            System.out.println(e.getComponent().getClass().getName() + " --- Shown");
        }
    }

    public static void main(String[] args) {
        CardlayoutTest t = new CardlayoutTest();
        t.setSize(500, 500);
        System.out.println("CardlayoutTest.main()------------------------ FIRST");
        t.card.show(t.getContentPane(), "A");
        t.setVisible(true);
        System.out.print("\n");
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
        }
        System.out.println("CardlayoutTest.main()------------------------ SECOND");
        t.card.show(t.getContentPane(), "B");
        System.out.print("\n");
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
        }
        System.out.println("CardlayoutTest.main()------------------------ THIRD");
        t.card.show(t.getContentPane(), "C");
        System.out.print("\n");
    }
}

有事件

CardlayoutTest.main（）------------------------第一个组件更改：   javax.swing.JPanel中[，0,0,0x0，无效，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件DISPLAYABILITY_CHANGED：   javax.swing.JPanel中[，0,0,0x0，无效，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   javax.swing.JPanel中[，0,0,0x0，无效，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件DISPLAYABILITY_CHANGED：   javax.swing.JPanel中[，0,0,0x0，无效，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   javax.swing.JPanel中[，0,0,0x0，无效，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件DISPLAYABILITY_CHANGED：   javax.swing.JPanel中[，0,0,0x0，无效，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，=标志16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]   组件SHOWING_CHANGED：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，=标志16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]   组件变更：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，=标志16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]   组件SHOWING_CHANGED：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，=标志16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]   组件变更：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，=标志16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]   组件SHOWING_CHANGED：   Listeners.CardlayoutTest [frame0,0,0,500x500，布局= java.awt.BorderLayout中，标题=，可调整大小的，正常的，defaultCloseOperation = EXIT_ON_CLOSE，的rootPane = javax.swing.JRootPane中[，8,31,484x461，布局= javax.swing中。 JRootPane的$ RootLayout，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 16777673，MAXIMUMSIZE =，=的minimumSize，首选大小=]，rootPaneCheckingEnabled =真]

CardlayoutTest.EventHandler.ancestorMoved（）javax.swing.JPanel ---   调整大小javax.swing.JPanel ---调整大小javax.swing.JPanel ---   调整大小的CardlayoutTest.EventHandler.ancestorMoved（）   CardlayoutTest.EventHandler.ancestorAdded（）   CardlayoutTest.main（）------------------------ SECOND Components   更改：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件SHOWING_CHANGED：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   javax.swing.JPanel中[，0,0,484x461，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件SHOWING_CHANGED：   javax.swing.JPanel中[，0,0,484x461，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   javax.swing.JPanel中[，0,0,484x461，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件SHOWING_CHANGED：   javax.swing.JPanel中[，0,0,484x461，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]

CardlayoutTest.EventHandler.ancestorRemoved（）javax.swing.JPanel ---   隐藏的CardlayoutTest.EventHandler.ancestorAdded（）javax.swing.JPanel   ---显示了javax.swing.JPanel ---显示了CardlayoutTest.main（）------------------------ THIRD组件更改：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件SHOWING_CHANGED：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件变更：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   组件SHOWING_CHANGED：   javax.swing.JPanel中[，0,0,484x461，隐藏，布局= java.awt.BorderLayout中，alignmentX = 0.0，alignmentY = 0.0，边界=，旗帜= 9，MAXIMUMSIZE =，=的minimumSize，首选大小=]   CardlayoutTest.EventHandler.ancestorRemoved（）javax.swing.JPanel ---   隐藏的javax.swing.JPanel ---隐藏

CardlayoutTest.EventHandler.ancestorAdded（）

Answer 2

在面板上实现AncestorListener，您想知道加载/卸载事件。我添加了一个显示和隐藏创建的JPanel的按钮。下面是相同的代码。 AncestorListener告诉我何时完全加载和卸载。

public class PanelTrial extends javax.swing.JPanel implements AncestorListener {

     private Container frame;
     private javax.swing.JPanel btnPanel;

     public PanelTrial(Container frame) {
           this.frame = frame;
           initComponents();
           createBtnPanel();
           btnPanel.addAncestorListener(this);
     }

      // Called on btn click event - to show/hide btnPanel
      private void updateRightPanel(boolean showBtnPanel) {
           jPanel1.removeAll();

           GroupLayout layout = (GroupLayout) jPanel1.getLayout();

           if (showBtnPanel) {
               layout.setHorizontalGroup(layout.createSequentialGroup()
                .addComponent(btnPanel));
               layout.setVerticalGroup(layout.createParallelGroup(
                Alignment.TRAILING).addComponent(btnPanel));

                } else {
                layout.setHorizontalGroup(layout.createSequentialGroup()
                .addComponent(rightPanel));
                layout.setVerticalGroup(layout.createParallelGroup(
                Alignment.TRAILING).addComponent(rightPanel));

            }

            jPanel1.validate();
            this.validate();
       }


     @Override
     public void ancestorAdded(AncestorEvent e) {
           if (e.getSource() == btnPanel) 
                System.out.println("BTNSPANEL LOADED / ADDED");
     }

     @Override
     public void ancestorMoved(AncestorEvent e) {
                 // This is of no use for your purpose 
           System.out.println("Anc Moved - " + e.getSource());
      }

      @Override
      public void ancestorRemoved(AncestorEvent e) {
           if (e.getSource() == btnPanel) 
             System.out.println("BTNSPANEL UNLOADED / REMOVED");
      }

检测JPanel卸载/关闭事件

2 个答案: