我的代码如下所示:
private void populateRoleNameComboBox() {
roleNameJComboBox.removeAllItems();
roleNameJComboBox.addItem(UserAccountDirectory.ADMIN_ROLE);
roleNameJComboBox.addItem(UserAccountDirectory.SALESPERSON_ROLE);
roleNameJComboBox.addItem(UserAccountDirectory.SUPPLIER_ROLE);
roleNameJComboBox.addItem(UserAccountDirectory.CUSTOMER_ROLE);
//populatePersonNameComboBox();
}
private void populatePersonNameComboBox() {
personNameJComboBox.removeAllItems();
if(roleNameJComboBox.getSelectedItem().equals(UserAccountDirectory.SUPPLIER_ROLE)){
for(Supplier s : supplierDirectory.getSupplierList()){
personNameJComboBox.addItem(s);
}
}
else if(roleNameJComboBox.getSelectedItem().equals(UserAccountDirectory.SALESPERSON_ROLE)){
for(Person p : employeeDirectory.getSalesPersonList()){
personNameJComboBox.addItem(p);
}
}
else if(roleNameJComboBox.getSelectedItem().equals(UserAccountDirectory.CUSTOMER_ROLE)){
for(Person person : customerDirectory.getCustomerList()){
personNameJComboBox.addItem(person);
}
}
}
我的 personNameJComboBox 没有显示任何值。如何实现逻辑以根据第一个组合框获取第二个组合框的值。
最佳答案
这是一个入门的简单示例。基本上,只要第一个组合框的所选项目发生变化,您就需要更改第二个组合框的模型。
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class ComboBoxTwo extends JFrame implements ActionListener
{
private JComboBox mainComboBox;
private JComboBox subComboBox;
private Hashtable subItems = new Hashtable();
public ComboBoxTwo()
{
String[] items = { "Select Item", "Color", "Shape", "Fruit" };
mainComboBox = new JComboBox( items );
mainComboBox.addActionListener( this );
// prevent action events from being fired when the up/down arrow keys are used
mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE);
getContentPane().add( mainComboBox, BorderLayout.WEST );
// Create sub combo box with multiple models
subComboBox = new JComboBox();
subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4
getContentPane().add( subComboBox, BorderLayout.EAST );
String[] subItems1 = { "Select Color", "Red", "Blue", "Green" };
subItems.put(items[1], subItems1);
String[] subItems2 = { "Select Shape", "Circle", "Square", "Triangle" };
subItems.put(items[2], subItems2);
String[] subItems3 = { "Select Fruit", "Apple", "Orange", "Banana" };
subItems.put(items[3], subItems3);
// mainComboBox.setSelectedIndex(1);
}
public void actionPerformed(ActionEvent e)
{
String item = (String)mainComboBox.getSelectedItem();
Object o = subItems.get( item );
if (o == null)
{
subComboBox.setModel( new DefaultComboBoxModel() );
}
else
{
subComboBox.setModel( new DefaultComboBoxModel( (String[])o ) );
}
}
public static void main(String[] args)
{
JFrame frame = new ComboBoxTwo();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setLocationRelativeTo( null );
frame.setVisible( true );
}
}
关于java - 如何获取组合框的值?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19575247/