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我有一個簡單的表單設置，我跟隨着本書Core Java Vol I如何設置表單，它們有一個頂級類，它擴展了JFrame創建不同組件的對象，並將它們放在框架中。如果這不是「通常」應該這樣做的方式，請讓我知道。混淆了內部類，簡單的動作
當我按下按鈕時編寫內部類來執行操作時，我感到困惑。我可以把我的內部類放在我的AddressBookForm類中，因爲這是我放置按鈕的位置，它可以訪問JTextFields的私有變量。我有問題（假設到目前爲止其他部分都是'好'），我不知道如何獲取addressList.size（），所以我可以更新我的statusBar標籤與插入按鈕時的總人數按下。有什麼想法嗎？謝謝。
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.List;
import java.util.ArrayList;
public class AddressBook
{
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
AddressBookFrame frame = new AddressBookFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JMenuBar menuBar = new JMenuBar();
frame.setJMenuBar(menuBar);
JMenu fileMenu = new JMenu("File");
JMenuItem openItem = new JMenuItem("Open");
JMenuItem saveItem = new JMenuItem("Save");
JMenuItem saveAsItem = new JMenuItem("Save As");
JMenuItem printItem = new JMenuItem("Print");
JMenuItem exitItem = new JMenuItem("Exit");
fileMenu.add(openItem);
fileMenu.add(saveItem);
fileMenu.add(saveAsItem);
fileMenu.add(printItem);
fileMenu.add(exitItem);
menuBar.add(fileMenu);
JMenu editMenu = new JMenu("Edit");
JMenuItem newItem = new JMenuItem("New");
JMenuItem editItem = new JMenuItem("Edit");
JMenuItem deleteItem = new JMenuItem("Delete");
JMenuItem findItem = new JMenuItem("Find");
JMenuItem firstItem = new JMenuItem("First");
JMenuItem previousItem = new JMenuItem("Previous");
JMenuItem nextItem = new JMenuItem("Next");
JMenuItem lastItem = new JMenuItem("Last");
editMenu.add(newItem);
editMenu.add(editItem);
editMenu.add(deleteItem);
editMenu.add(findItem);
editMenu.add(firstItem);
editMenu.add(previousItem);
editMenu.add(nextItem);
editMenu.add(lastItem);
menuBar.add(editMenu);
JMenu helpMenu = new JMenu("Help");
JMenuItem documentationItem = new JMenuItem("Documentation");
JMenuItem aboutItem = new JMenuItem("About");
helpMenu.add(documentationItem);
helpMenu.add(aboutItem);
menuBar.add(helpMenu);
frame.setVisible(true);
}
});
}
}
class AddressBookFrame extends JFrame
{
public AddressBookFrame()
{
setLayout(new BorderLayout());
setTitle("Address Book");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
AddressBookToolBar toolBar = new AddressBookToolBar();
add(toolBar, BorderLayout.NORTH);
AddressBookStatusBar aStatusBar = new AddressBookStatusBar();
add(aStatusBar, BorderLayout.SOUTH);
AddressBookForm form = new AddressBookForm();
add(form, BorderLayout.CENTER);
}
public static final int DEFAULT_WIDTH = 500;
public static final int DEFAULT_HEIGHT = 500;
}
/* Create toolbar buttons and add buttons to toolbar */
class AddressBookToolBar extends JPanel
{
public AddressBookToolBar()
{
setLayout(new FlowLayout(FlowLayout.LEFT));
JToolBar bar = new JToolBar();
JButton newButton = new JButton("New");
JButton editButton = new JButton("Edit");
JButton deleteButton = new JButton("Delete");
JButton findButton = new JButton("Find");
JButton firstButton = new JButton("First");
JButton previousButton = new JButton("Previous");
JButton nextButton = new JButton("Next");
JButton lastButton = new JButton("Last");
bar.add(newButton);
bar.add(editButton);
bar.add(deleteButton);
bar.add(findButton);
bar.add(firstButton);
bar.add(previousButton);
bar.add(nextButton);
bar.add(lastButton);
add(bar);
}
}
/* Creates the status bar string */
class AddressBookStatusBar extends JPanel
{
public AddressBookStatusBar()
{
setLayout(new FlowLayout(FlowLayout.LEFT));
this.statusBarString = new JLabel("Total: " + totalContacts);
add(this.statusBarString);
}
public void updateLabel(int n)
{
contactsLabel.setText((new Integer(n)).toString());
}
private JLabel statusBarString;
private JLabel contactsLabel;
}
class AddressBookForm extends JPanel
{
public AddressBookForm()
{
// create form panel
this.setLayout(new GridLayout(2, 1));
JPanel formPanel = new JPanel();
formPanel.setLayout(new GridLayout(4, 2));
firstName = new JTextField(20);
lastName = new JTextField(20);
telephone = new JTextField(20);
email = new JTextField(20);
JLabel firstNameLabel = new JLabel("First Name: ", JLabel.LEFT);
formPanel.add(firstNameLabel);
formPanel.add(firstName);
JLabel lastNameLabel = new JLabel("Last Name: ", JLabel.LEFT);
formPanel.add(lastNameLabel);
formPanel.add(lastName);
JLabel telephoneLabel = new JLabel("Telephone: ", JLabel.LEFT);
formPanel.add(telephoneLabel);
formPanel.add(telephone);
JLabel emailLabel = new JLabel("Email: ", JLabel.LEFT);
formPanel.add(emailLabel);
formPanel.add(email);
add(formPanel);
// create button panel
JPanel buttonPanel = new JPanel();
JButton insertButton = new JButton("Insert");
JButton displayButton = new JButton("Display");
ActionListener insertAction = new AddressBookListener();
ActionListener displayAction = new AddressBookListener();
insertButton.addActionListener(insertAction);
displayButton.addActionListener(displayAction);
buttonPanel.add(insertButton);
buttonPanel.add(displayButton);
add(buttonPanel);
}
public int getTotalContacts()
{
return addressList.size();
}
private JTextField firstName;
private JTextField lastName;
private JTextField telephone;
private JTextField email;
private JLabel contacts;
private List<Person> addressList = new ArrayList<Person>();
private class AddressBookListener implements ActionListener
{
public void actionPerformed(ActionEvent e)
{
String buttonPressed = e.getActionCommand();
System.out.println(buttonPressed);
if (buttonPressed == "Insert") {
Person aPerson = new Person(firstName.getText(), lastName.getText(), telephone.getText(), email.getText());
addressList.add(aPerson);
}
else {
for (Person p : addressList) {
System.out.println(p);
}
}
}
}
}
我不認爲我完全得到它。所以這個服務是一個幫手類。我會在哪裏申報我的名單？它是一個類的私有變量嗎？我想我沒有看到兩個單獨的類將如何訪問相同的列表。 –
Crystal
2010-06-10 04:19:00
您在助手類中聲明瞭列表，將輔助類注入組件並調用addressBookService.getContacts（），而不是在本地存儲列表。 – 2010-06-10 04:39:18