2番目のコンボボックスを埋める方法

Question

トルコの2番目のコンボを埋める方法は？ 最初のコンボの七面鳥を選択すると、アンカラ・イズミールは第2のコンボになりました。

String[] s = {"Turkey", "Rusia", "Italia"}; 
     for (String string : s) { 
      comboBox.addItem(string); 
     } 
     String x = String.valueOf(comboBox.getSelectedItem()); 
     if (x.equalsIgnoreCase("Turkey")) { 
      String[] s1 = {"Ankara", "Izmir"}; 
      for (String ss : s1) { 
       comboBox1.addItem(ss); 
      } 
     } 

Answer 1

 //Add this import 
     import javax.swing.DefaultComboBoxModel; 

     DefaultComboBoxModel dcm = new DefaultComboBoxModel();   

     String[] s = {"Turkey", "Rusia", "Italia"}; 
     // set the datamodel for the second combo box 

     jComboBox2.setModel(dcm); 
     // in the action perform method of the compbo box, add this code 


     private void comboBoxActionPerformed(java.awt.event.ActionEvent evt) {  

    String x = String.valueOf(comboBox.getSelectedItem()); 
    if (x.equalsIgnoreCase("Turkey")) { 
     String[] s1 = {"Ankara", "Izmir"}; 
     for (String ss : s1) { 
      dcm.addElement(ss); 
     } 
    jComboBox2.setModel(dcm); 

    } 

Answer 2

あなたは、項目が選択されたときにアクションを実行するために最初のコンボボックスにActionListenerを追加する必要があります。

ような何か：あなたは別のモデルでは、配列を変更し、最終的に別のJComboBoxのに別のモデルを追加し、その後のItemListenerから、配列の必要数を準備するために、DeafultComboBoxModel（S）でプレイしている

import java.awt.*; 
import java.awt.event.*; 
import java.util.*; 
import javax.swing.*; 
import javax.swing.plaf.basic.*; 

public class ComboBoxTwo extends JPanel implements ActionListener 
{ 
    private JComboBox<String> mainComboBox; 
    private JComboBox<String> subComboBox; 
    private Hashtable<String, String[]> subItems = new Hashtable<String, String[]>(); 

    public ComboBoxTwo() 
    { 
     String[] items = { "Select Item", "Color", "Shape", "Fruit" }; 
     mainComboBox = new JComboBox<String>(items); 
     mainComboBox.addActionListener(this); 

     // prevent action events from being fired when the up/down arrow keys are used 
     mainComboBox.putClientProperty("JComboBox.isTableCellEditor", Boolean.TRUE); 
     add(mainComboBox); 

     // Create sub combo box with multiple models 

     subComboBox = new JComboBox<String>(); 
     subComboBox.setPrototypeDisplayValue("XXXXXXXXXX"); // JDK1.4 
     add(subComboBox); 

     JButton arrow = SwingUtils.getDescendantOfType(JButton.class, subComboBox, "Text", ""); 
     Dimension d = arrow.getPreferredSize(); 
     System.out.println(arrow.getClass()); 
     System.out.println(d); 
     d.width = 35; 
     arrow.setPreferredSize(d); 

     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); 
    } 

    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)); 
     } 
    } 

    private static void createAndShowUI() 
    { 
     try 
     { 
//   UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
     } 
     catch (Exception e) { } 
     JFrame frame = new JFrame("SSCCE"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.add(new ComboBoxTwo()); 
     frame.setLocationByPlatform(true); 
     frame.pack(); 
     frame.setVisible(true); 
    } 

    public static void main(String[] args) 
    { 
     EventQueue.invokeLater(new Runnable() 
     { 
      public void run() 
      { 
       createAndShowUI(); 
      } 
     }); 
    } 
}