我正在为我想参加的计划进行评估。我仍然对如何解释，理解或正确使用＆＃34;教程＆＃34;位于Tutorials Point，由该计划提供。
使用Netbeans 8.1创建的Jlist - ＆gt; JFrame表单GUI生成器
public class Window extends javax.swing.JFrame {
/**
* Creates new form for BootcampAssessmentGui
*/
public Window() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
controlsbuttonGroup = new javax.swing.ButtonGroup();
partsScrollPane = new javax.swing.JScrollPane();
partsList = new javax.swing.JList<>();
buildScrollPane = new javax.swing.JScrollPane();
buildList = new javax.swing.JList<>();
addButton = new javax.swing.JButton();
removeButton = new javax.swing.JButton();
jMenuBar1 = new javax.swing.JMenuBar();
fileMenu = new javax.swing.JMenu();
loadMenuItem = new javax.swing.JMenuItem();
saveMenuItem = new javax.swing.JMenuItem();
exitMenuItem = new javax.swing.JMenuItem();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Devereaux Assessment");
partsList.setModel(new javax.swing.AbstractListModel<String>() {
String[] strings = { "Case", "Motherboard", "CPU", "RAM", "GPU", "HDD", "PSU" };
public int getSize() { return strings.length; }
public String getElementAt(int i) { return strings[i]; }
});
partsScrollPane.setViewportView(partsList);
buildScrollPane.setViewportView(buildList);
addButton.setText(">>");
addButton.setToolTipText("Add Parts to Build list");
controlsbuttonGroup.add(addButton);
addButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
addButtonActionPerformed(evt);
}
});
removeButton.setText("<<");
removeButton.setToolTipText("Remove Parts from Build list");
controlsbuttonGroup.add(removeButton);
removeButton.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
removeButtonActionPerformed(evt);
}
});
fileMenu.setText("File");
loadMenuItem.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_L, java.awt.event.InputEvent.CTRL_MASK));
loadMenuItem.setIcon(new javax.swing.ImageIcon(getClass().getResource("/com/cooksys/assessment/arrow95.png"))); // NOI18N
loadMenuItem.setText("Load");
fileMenu.add(loadMenuItem);
saveMenuItem.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_S, java.awt.event.InputEvent.CTRL_MASK));
saveMenuItem.setIcon(new javax.swing.ImageIcon(getClass().getResource("/com/cooksys/assessment/floppy13.png"))); // NOI18N
saveMenuItem.setText("Save");
fileMenu.add(saveMenuItem);
exitMenuItem.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_X, java.awt.event.InputEvent.CTRL_MASK));
exitMenuItem.setIcon(new javax.swing.ImageIcon(getClass().getResource("/com/cooksys/assessment/exit18.png"))); // NOI18N
exitMenuItem.setText("Exit");
exitMenuItem.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
exitMenuItemActionPerformed(evt);
}
});
fileMenu.add(exitMenuItem);
jMenuBar1.add(fileMenu);
setJMenuBar(jMenuBar1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(partsScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 209, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 31, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(addButton)
.addComponent(removeButton))
.addGap(28, 28, 28)
.addComponent(buildScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 209, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(buildScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 279, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(partsScrollPane, javax.swing.GroupLayout.PREFERRED_SIZE, 279, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createSequentialGroup()
.addGap(125, 125, 125)
.addComponent(addButton)
.addGap(18, 18, 18)
.addComponent(removeButton)))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void exitMenuItemActionPerformed(java.awt.event.ActionEvent evt) {
System.exit(0);
}
private void addButtonActionPerformed(java.awt.event.ActionEvent evt) {
// add Parts to buildList
for (Object selectedValue : partsList.getSelectedValuesList()) {
buildList.addElement(selectedValue);
partsList.removeElement(selectedValue);
int iSelected = partsList.getSelectedIndex();
if (iSelected == -1) {
return;
}
}
}
private void removeButtonActionPerformed(java.awt.event.ActionEvent evt) {
// remove Parts from buildList
for (Object selectedValue : buildList.getSelectedValuesList()) {
partsList.addElement(selectedValue);
buildList.removeElement(selectedValue);
int iSelected = buildList.getSelectedIndex();
if (iSelected == -1) {
return;
}
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Window.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Window.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Window.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Window.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Window().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton addButton;
private javax.swing.JList<String> buildList;
private javax.swing.JScrollPane buildScrollPane;
private javax.swing.ButtonGroup controlsbuttonGroup;
private javax.swing.JMenuItem exitMenuItem;
private javax.swing.JMenu fileMenu;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JMenuItem loadMenuItem;
private javax.swing.JList<String> partsList;
private javax.swing.JScrollPane partsScrollPane;
private javax.swing.JButton removeButton;
private javax.swing.JMenuItem saveMenuItem;
// End of variables declaration
}
我收到错误无法找到符号 - 符号：方法addElement（Object） location：变量partsList类型的Jlist
错误对我来说非常简单。我的问题是我见过的大多数使用DefaultListModel的例子。 NetBeans正在使用AbstractListModel方法。
我已阅读以下参考资料：
http://www.java2s.com/Code/Java/Swing-JFC/DualJListwithbuttonsinbetween.htm http://docs.oracle.com/javase/tutorial/uiswing/components/list.html#scrollingapi
但老实说，我觉得我没有正确理解这些来源如何用于调试。我觉得我没有正确使用对象 - ＆gt;基于这段代码的字符串：
private void clearDestinationSelected() {
Object selected[] = destList.getSelectedValues();
for (int i = selected.length - 1; i >= 0; --i) {
destListModel.removeElement(selected[i]);
}
destList.getSelectionModel().clearSelection();
}
我将通过评论在代码中包含此协助请求。我不是骗子。我已经查看，工作，搜索并思考了几天。在这一点上，我觉得寻求帮助是谨慎的。
答案 0 :(得分：2)
API会在这里帮助你，因为如果你看看JList API，你会看到你的编译器是正确的，JList没有addElement(...)方法，但不要丢心 - - DefaultListModel类确实具有此方法，您可以通过调用getModel()从JList中提取此方法，然后在提取的模型上调用addElement(...)。
编辑：不好，你使用自己的AbstractListModel派生的模型 - 你需要让你的模型非抽象 - 给它一个类名，然后给你的Model类一个addElement方法。或者更简单地说，使用填充数据的DefaultListModel对象。