Java CardLayout工作不正常
我用Splitpane、Combobox和其他几个包含按钮和标签的面板编写了这个简单的Cardlayout示例Java CardLayout工作不正常,java,swing,jsplitpane,cardlayout,Java,Swing,Jsplitpane,Cardlayout,我用Splitpane、Combobox和其他几个包含按钮和标签的面板编写了这个简单的Cardlayout示例 import java.awt.BorderLayout; import java.awt.CardLayout; import java.awt.Container; import java.awt.EventQueue; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import java
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Container;
import java.awt.EventQueue;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSplitPane;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
public class splitpane_test extends JFrame implements ItemListener {
private JPanel contentPane;
final static String BUTTONPANEL = "Card with JButtons";
final static String TEXTPANEL = "Card with JTextField";
JPanel cards;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
splitpane_test frame = new splitpane_test();
//frame.addComponentToPane(frame.getContentPane());
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public splitpane_test() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JSplitPane splitPane = new JSplitPane();
contentPane.add(splitPane, BorderLayout.CENTER);
JPanel comboBoxPane = new JPanel();
String comboBoxItems[] = {BUTTONPANEL, TEXTPANEL};
JComboBox cb = new JComboBox(comboBoxItems);
cb.setEditable(false);
cb.addItemListener(this);
comboBoxPane.add(cb);
splitPane.setLeftComponent(comboBoxPane);
//Create the "cards".
JPanel card1 = new JPanel();
card1.add(new JButton("Button 1"));
card1.add(new JButton("Button 2"));
card1.add(new JButton("Button 3"));
JPanel card2 = new JPanel();
card2.add(new JTextField("TextField", 20));
//Create the panel that contains the "cards".
cards = new JPanel();
cards.add(card1, BUTTONPANEL);
cards.add(card2, TEXTPANEL);
splitPane.setRightComponent(cards);
cards.setLayout(new CardLayout(0, 0));
}
@Override
public void itemStateChanged(ItemEvent e) {
// TODO Auto-generated method stub
System.out.print("Event Triggered \n");
CardLayout cl = (CardLayout) (cards.getLayout());
cl.show(cards, TEXTPANEL);
}
}
我可以看到左边有combobox的splitpane,右边有其他cardlayout面板。
当我更改组合框项目时,没有任何事情发生在正确的大小上。
为了验证我是否击中了卡出,我使用了
系统输出打印(“事件触发\n”)强>
但我看到的令人惊讶的事情是,它为每个组合框项显示两次,就像它调用两次一样
Event Triggered
Event Triggered
事件触发
事件触发
你能告诉我我做错了什么,为什么触发的事件会被两次击中吗。
谢谢你的时间和帮助
System.out.println(“事件触发:+e”)代码>
TEXTPANEL
你能告诉我我做错了什么,为什么触发的事件会被击中两次吗
如果查看项目事件
,您将看到一个项目被取消选择,另一个项目被选择。相反,如图所示,收听ActionEvent
,并相应地选择正确的卡
附录:如果您在@Michael Brewer Davis中实施了有益的更改,那么合适的ActionListener
尤其简单:
@Override
public void actionPerformed(ActionEvent e) {
JComboBox jcb = (JComboBox) e.getSource();
CardLayout cl = (CardLayout) cards.getLayout();
cl.show(cards, jcb.getSelectedItem().toString());
}
+我试着用JTree替换combobox,看看它是否能做到同样的效果,但还是不起作用<代码>代码CardLayout c1=(CardLayout)(cards.getLayout());DefaultMutableTreeNode sel=(DefaultMutableTreeNode)树。getLastSelectedPathComponent();如果(sel.isLeaf()){System.out.println(sel+e.getSource().toString());c1.show(cards,sel.toString());}我可以看到调用的面板是正确的,但cardlayout没有改变。如果我手动使用面板名称,它会工作。请告诉我我所犯的错误。非常感谢您的帮助。请查看
DefaultMutableTreeNode.getUserObject()
谢谢您的回答,但它似乎不起作用<代码>代码公共无效值更改(TreeSelection事件e){CardLayout c1=(CardLayout)(cards.getLayout());DefaultMutableTreeNode=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();if(node.isLeaf()){System.out.println(node.getUserObject());c1.show(cards,(String)node.getUserObject();}