上面那个界面里的下拉式列表（即“苹果呵呵呵”） 每次点击下拉就会出异常，异常信息如下 :
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: cannot add to layout: constraint must be a string (or null)
at java.awt.BorderLayout.addLayoutComponent(BorderLayout.java:426)
at java.awt.Container.addImpl(Container.java:1125)
at javax.swing.JLayeredPane.addImpl(JLayeredPane.java:231)
at java.awt.Container.add(Container.java:1003)
at javax.swing.PopupFactory$LightWeightPopup.show(PopupFactory.java:754)
at javax.swing.JPopupMenu.showPopup(JPopupMenu.java:842)
at javax.swing.JPopupMenu.setVisible(JPopupMenu.java:790)
at javax.swing.JPopupMenu.show(JPopupMenu.java:965)
at javax.swing.plaf.basic.BasicComboPopup.show(BasicComboPopup.java:207)
at javax.swing.plaf.basic.BasicComboPopup.togglePopup(BasicComboPopup.java:1127)
at javax.swing.plaf.basic.BasicComboPopup$Handler.mousePressed(BasicComboPopup.java:824)
at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:280)
at java.awt.Component.processMouseEvent(Component.java:6524)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6292)
at java.awt.Container.processEvent(Container.java:2234)[/color]
at java.awt.Component.dispatchEventImpl(Component.java:4883)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4530)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:719)
at java.awt.EventQueue$4.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)[/color]
求助帮忙看看是我的代码写的有问题吗..？或是加载的package有问题..? 下面是我写的代码.. ：
package manager_ui;
import java.awt.BorderLayout;
import java.awt.*;
import java.awt.GridLayout;
import java.awt.event.*;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.BorderFactory;
import javax.swing.ComboBoxModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import javax.swing.filechooser.FileFilter;
import javax.swing.filechooser.FileNameExtensionFilter;
//import javax.swing.JComboBoxDemo.Model;
//import com.hanfeng.ui.UI.Conversion1;
public class manager_ui extends JFrame {
private JTextField jtfa;
private JComboBox jComboBox1;
private JButton jba;
private JTextField jwordpath;
private JTextField jwordOpath;
private JTextField jword;
private JButton jfilepath;
private JButton jwordname;
private JButton jwordOname;
private JButton jbc;
private String[] fruit={"苹果呵呵呵","香蕉","桔子","梨","芒果"};
private JButton jtrans;
public manager_ui() {
super("自动化工具");
}
public void initUI(){
//this.getContentPane().setLayout(new GridBagLayout());
this.setBounds(450, 450, 750, 600);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e) {
super.windowClosing(e);
System.exit(0);
}});