我的窗口上有3个jpanel,我想在窗口上实现功能，根据菜单选择，可以在执行时选择窗口布局方式，可以么？我的代码怎么没反应呢？

Question

试试调用revalidate(),repaint()等函数,
你所说的不起作用估计是因为没有通知程序布局已经改变

Answer 1

有没有调用到代码呢？System.out.println试试。
如果没有，写成public void actionPerformed(ActionEvent e){...}

Answer 2

好多错误提示；但看了不明白，调用到代码了，但revalidate()怎么用啊，继续请教。Exception occurred during event dispatching:java.lang.IllegalArgumentException: wrong parent for CardLayout at java.awt.CardLayout.checkLayout(CardLayout.java:326) at java.awt.CardLayout.show(CardLayout.java:443) at imageviewer.AnalysisImageFrame1.show3window_actionPerformed(AnalysisImageFrame1.java:417) at imageviewer.AnalysisImageFrame1$12.actionPerformed(AnalysisImageFrame1.java:184) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1450) at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1504) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:378) at javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.java:268) at javax.swing.AbstractButton.doClick(AbstractButton.java:279) at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(BasicMenuItemUI.java:886) at java.awt.Component.processMouseEvent(Component.java:3715) at java.awt.Component.processEvent(Component.java:3544) at java.awt.Container.processEvent(Container.java:1164) at java.awt.Component.dispatchEventImpl(Component.java:2593) at java.awt.Container.dispatchEventImpl(Container.java:1213) at java.awt.Component.dispatchEvent(Component.java:2497) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:2451) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2216) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125) at java.awt.Container.dispatchEventImpl(Container.java:1200) at java.awt.Window.dispatchEventImpl(Window.java:914) at java.awt.Component.dispatchEvent(Component.java:2497) at java.awt.EventQueue.dispatchEvent(EventQueue.java:339) at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:131) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:98) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)

Answer 3

好多错误提示；但看了不明白，调用到代码了，但revalidate()怎么用啊，继续请教。Exception occurred during event dispatching:java.lang.IllegalArgumentException: wrong parent for CardLayout at java.awt.CardLayout.checkLayout(CardLayout.java:326) at java.awt.CardLayout.show(CardLayout.java:443) at imageviewer.AnalysisImageFrame1.show3window_actionPerformed(AnalysisImageFrame1.java:417) at imageviewer.AnalysisImageFrame1$12.actionPerformed(AnalysisImageFrame1.java:184) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1450) at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1504) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:378) at javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.java:268) at javax.swing.AbstractButton.doClick(AbstractButton.java:279) at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseReleased(BasicMenuItemUI.java:886) at java.awt.Component.processMouseEvent(Component.java:3715) at java.awt.Component.processEvent(Component.java:3544) at java.awt.Container.processEvent(Container.java:1164) at java.awt.Component.dispatchEventImpl(Component.java:2593) at java.awt.Container.dispatchEventImpl(Container.java:1213) at java.awt.Component.dispatchEvent(Component.java:2497) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:2451) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2216) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2125) at java.awt.Container.dispatchEventImpl(Container.java:1200) at java.awt.Window.dispatchEventImpl(Window.java:914) at java.awt.Component.dispatchEvent(Component.java:2497) at java.awt.EventQueue.dispatchEvent(EventQueue.java:339) at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:131) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:98) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:85)

Answer 4

     1.可以用菜单选项改变窗体布局
     2. 用repaint()应该不可以。
     3. 仅供参考：
          public void actionPerformed(ActionEvent evt){
    content＝getContentPane();
    Object source=evt.getSource();
    if (source==bordermenu){
      content.setLayout(new BorderLayout());
      content.add(test1,BorderLayout.NORTH);
      content.add(test2,BorderLayout.CENTER);
      //改变布局
      pack();
      doLayout();
      }
    else if (source==gridmenu)
    {
      content.setLayout(null);
      content.setLayout(new GridLayout(1,2));
      content.add(test1);
      content.add(test2);
      pack();
      doLayout();
    }
  }good luky!!

Answer 5

这段程序原来FlowLayout ,想在CardLayout和FlowLayout中任意替换，但变CardLayout是好使，还原成FlowLayout就只显示一个图，别的图没了，怎么回事？ if(show3window.getState()){
      jPanel1.setLayout(null);
      jPanel1.setLayout(cardLayout1);
      jPanel1.add(jPanel2,"jPanel2");
      jPanel1.add(jPanel3,"jPanel3");
      jPanel1.add(jPanel4,"jPanel4");
      pack();
      doLayout();
      cardLayout1.first(jPanel1);    }
    if(!show3window.getState()){
      jPanel1.setLayout(flowLayout2);
      jPanel1.add(jPanel2, "jPanel2");
      jPanel1.add(jPanel4, "jPanel4");
      jPanel1.add(jPanel3, "jPanel3");
      pack();
      doLayout();
   }