我有以下问题: 有2个JList的在我的框架:爪哇 - 清除选择在其他的JList
listModel = new DefaultListModel();
ownlistModel = new DefaultListModel();
fillList();
ownBookList = new JList(ownlistModel);
ownBookList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
ownBookList.setLayoutOrientation(JList.VERTICAL);
ownBookList.setSelectedIndex(-1);
userlist = new JList(listModel);
userlist.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
userlist.setLayoutOrientation(JList.VERTICAL);
userlist.setSelectedIndex(0);
现在,这些是互斥的,所以如果有人在一个列表中点击一个项目,应清除其他列表中的先前选择。
ls2Handler = new ListSelectionListener(){
@Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting() == false) {
// System.out.println(ownBookList.getSelectedValue().toString().length());
Global.selectedUser = ownBookList.getSelectedValue().toString();
Global.selectedIndex = ownBookList.getSelectedIndex();
userlist.clearSelection();
updateFields(Global.selectedUser, 1);
}
}
};
lsHandler = new ListSelectionListener() {
@Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting() == false) {
// System.out.println(userlist.getSelectedValue().toString().length());
Global.selectedUser = userlist.getSelectedValue().toString();
Global.selectedIndex = userlist.getSelectedIndex();
ownBookList.clearSelection();
updateFields(Global.selectedUser, 0);
}
}
};
userlist.addListSelectionListener(lsHandler);
ownBookList.addListSelectionListener(ls2Handler);
在调用值是调节功能,我总是得到NullPointerException异常:
在书籍$ 3.valueChanged(书籍异常在线程 “AWT-EventQueue的-0” 显示java.lang.NullPointerException 。 javax.swing.JList.fireSelectionValueChanged(Unknown Source)
为什么?正如你所看到的,它们已经被宣布并且应该可以访问。
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