Question

我编写了一个程序，假设设置了应用程序属性。我正在使用JSplit Pane和JScrollPane。程序正在加载正常，但它没有更改右面板的值以响应左侧的列表元素。如果我做错了，请告诉我。我已提到following program

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JDialog;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTabbedPane;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class ApplicationPropertyDlg extends JDialog implements ActionListener,ListSelectionListener {

   private DButton     pb_OK           = null ;
   private DButton     pb_CANCEL       = null ;
   private DButton     pb_APPLY        = null ;
   private String[]         appProp     = null;
   private JList            appList     = null;
   private JSplitPane       appPanel    = null;
   private JScrollPane      listScrollPanel,appScrollPanel  = null; 

   public ApplicationPropertyDlg ( AppDefaultWin parent ) {
      super ( parent, "Properties Application", true ) ;
      initializeAppProp();
      intializeAppList();
      initializeGUI();
      ButtonPanel buttonPanel = new ButtonPanel () ;
      setSize ( 800,700 ) ;
      WinUtil.centerChildInParent ( this, parent ) ;          
      pb_OK     = new JButton ( ) ;
      pb_APPLY  = new JButton ( ) ;
      pb_CANCEL = new JButton ( ) ;

      pb_OK.addActionListener ( this ) ;
      pb_APPLY.addActionListener ( this ) ;
      pb_CANCEL.addActionListener ( this ) ;
      GUISystem.setPreferredButton ( pb_OK ) ;
      GUISystem.setPreferredButton ( pb_CANCEL ) ;
      GUISystem.setPreferredButton ( pb_APPLY ) ;
      getContentPane().setLayout ( new BorderLayout (5,5) ) ;
      getContentPane().add(appPanel);
      getContentPane().add ( buttonPanel, BorderLayout.SOUTH ) ;
      buttonPanel.add ( pb_OK ) ;
      buttonPanel.add ( pb_APPLY ) ;
      buttonPanel.add ( pb_CANCEL ) ;                                 
      setVisible ( true ) ;   
   }

   private void initializeGUI() {
    // TODO Auto-generated method stub
       listScrollPanel = new JScrollPane(appList);
       appScrollPanel = new JScrollPane(new GeneralPage());
       appPanel = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,listScrollPanel,appScrollPanel);
       appPanel.setOneTouchExpandable(true);
       appPanel.setDividerLocation(200);
       //minimum size for individual Panel
       Dimension minimumSize = new Dimension(100, 50);
       listScrollPanel.setMinimumSize(minimumSize);
       appScrollPanel.setMinimumSize(minimumSize);
       //Provide a preferred size for the split pane.
       appPanel.setPreferredSize(appPanel.getPreferredSize());     

}


private void intializeAppList() {
    // TODO Auto-generated method stub
       appList = new JList(appProp);
       appList.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
       appList.setSelectedIndex(0);
       appList.addListSelectionListener(this);


}





private void initializeAppProp() {
    // TODO Auto-generated method stub
    appProp = new String []{"General","Task Bar", "Look and Feel","Country"};
}

   public void propertyChanged ( int property, Object value ) {
      if ( property == PropertySystem.PROPERTY_LANGUAGE )
         setText() ;
      else if ( property == PropertySystem.PROPERTY_LAF )
         GUISystem.setLookAndFeel ( this ) ;
      else
         GUISystem.setPropertiesOnPanel ( getContentPane() ) ;
   }




   public void actionPerformed ( ActionEvent e ) {
         dispose() ;
   }



@Override
public void valueChanged(ListSelectionEvent e) {
    // TODO Auto-generated method stub
    JList list = (JList)e.getSource();
    updateAppPanel(appProp[list.getSelectedIndex()]);

}

private void updateAppPanel(String panelName) {
    // TODO Auto-generated method stub
    if(panelName.equalsIgnoreCase("General"){
        appScrollPanel.removeAll();
        appScrollPanel.add(new GeneralPage());
    }
    else if (panelName.equalsIgnoreCase("Task Bar"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new TaskBarPage());
    }
    else if (panelName.equalsIgnoreCase("Language"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new LanguagePage());
    }
    else if (panelName.equalsIgnoreCase("Look and Feel"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new LookFeelPage());
    }
    else if (panelName.equalsIgnoreCase("Country"){
        appScrollPanel.removeAll();
        appScrollPanel.setViewportView(new SelectCountryPage());
    }
    appScrollPanel.revalidate();
    appScrollPanel.repaint();   
    }
}

Answer 1

首先，向类中添加一个新的控件容器（最好是JPanel）：

    ...
    private JSplitPane       appPanel    = null;
    private JScrollPane      listScrollPanel,appScrollPanel  = null;
    // End of your controls...

    private JPanel tabContainer;

然后，在您的代码初始化appScrollPanel变量的代码部分中，不是传递GeneralPane的新实例，而是像这样传递tabContainer：

     tabContainer = new JPanel();
     tabContainer.setLayout(new CardLayout());
     tabContainer.add(new GeneralPage());
     // Instead of adding GeneralPane directly, add the GeneralPane container
     appScrollPanel = new JScrollPane(tabContainer);

然后，在updateAppPanel方法中，替换appScrollPanel.setViewportView这样的调用：

private void updateAppPanel(String panelName) {
    // TODO Auto-generated method stub
    if(panelName.equalsIgnoreCase("General")){
        tabContainer.removeAll();
        tabContainer.add(new GeneralPage());
    } 
    else if (panelName.equalsIgnoreCase("Task Bar")){
        tabContainer.removeAll();
        tabContainer.add(new TaskBarPage());
    }
    else if (panelName.equalsIgnoreCase("Language")){
        tabContainer.removeAll();
        tabContainer.add(new LanguagePage());
    }
    else if (panelName.equalsIgnoreCase("Look and Feel")){
        tabContainer.removeAll();
        tabContainer.add(new LookFeelPage());
    } 
    else if (panelName.equalsIgnoreCase("Country")){
        tabContainer.removeAll();
        tabContainer.add(new CountryPage());
    }
    appScrollPanel.revalidate();
    appScrollPanel.repaint();   
}

它应该有效：

enter image description here

我建议您将updateAppPanel代码放在循环中吗？如果你需要修改每个else if块的内部主体

，它可以省去一些麻烦

JScrollPane不会将值更改为ListEvents

1 个答案: