从Jlist中删除项目

Question

我有一个简单的JLIST，其中包含来自List<String>的数据，现在我想从JLIST中删除选定的项目。这是代码：

final DefaultListModel<String> model = new DefaultListModel();
final JList list = new JList(model);
//filling list
//loop for every element from List<String>
 public static void sample(DefaultListModel model, List<String> data)
      for(int i=;i<data.size();i++)
        {model.addElement(data.get(i));}
//btn pressed
public void actionPerformed(ActionEvent arg0) {
    int index = list.getSelectedIndex();
    model.removeElementAt(index);
}

我得到此错误：

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: -1
at java.util.ArrayList.elementData(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at javax.swing.JList.fireSelectionValueChanged(Unknown Source)
at javax.swing.JList$ListSelectionHandler.valueChanged(Unknown Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown Source)
at javax.swing.DefaultListSelectionModel.removeIndexInterval(Unknown Source)
at javax.swing.plaf.basic.BasicListUI$Handler.intervalRemoved(Unknown Source)
at javax.swing.AbstractListModel.fireIntervalRemoved(Unknown Source)
at javax.swing.DefaultListModel.remove(Unknown Source)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

有什么窍门还是什么？感谢您的帮助。

Answer 1

假设您的索引是非负的（其他人提到的），请参阅（在听众中）是否有效：

((DefaultListModel) jList.getModel()).remove(index);

如果是这样，那么您正在使用陈旧的型号。

Answer 2

根据Javadoc，建议使用remove()代替removeElementAt()，因此：

public void actionPerformed(ActionEvent arg0) {
    int index = list.getSelectedIndex();
    if (index != -1) {
        model.remove(index);
}

Answer 3

根据 getSelectedIndex()的javadoc：

返回最小的选定单元格索引；只有一个 单项在列表中选择。选择多个项目时， 它只是最小的选定索引。返回-1如果没有 选择

您遇到错误的原因是因为出于某种原因，从您的列表中选择了任何项目，因此由此方法返回-1。当您致电removeElementAt()并将其传递-1作为参数值时，它会给您带来例外。

您需要做的是如下：

public void actionPerformed(ActionEvent arg0) {
    int index = list.getSelectedIndex();
    if(index >= 0){ //Remove only if a particular item is selected
        model.removeElementAt(index);
    }
}

Answer 4

问题是您在侦听器中有问题，因为当元素被删除时，所选值将会更改。这就是您的"评估"方法试图使所选值处于错误位置的原因。我看不到您的方法有价值，但我认为这是原因。

Answer 5

DefaultListModel model=new DefaultListModel();
    model.clear();
 jList1.setModel(model);

如果要删除所有项目

Answer 6

int selectedIndex = yourJLIST.getSelectedIndex();
    String [] ListData = new String[yourJLIST.getModel().getSize()];
    for (int i = 0; i < ListData.length; i++) {
        if(i == selectedIndex){
            
        }else{
            ListData[i] = yourJLIST.getModel().getElementAt(i);
        }
    }
    yourJLIST.setListData(ListData);