從JComboBox顯示JTextField中的數據

Question

我希望通過檢查JCheckBox從swing中獲取JComboBox中的值並將其顯示在JTextField中的代碼，以及 setFocus轉換爲JTextField。初始化JTextField應該是空的。當顯示JCheckBox時，顯示JTextField中JComboBox中選定的項目。

Answer 1

示例代碼：

import java.awt.GridLayout; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import javax.swing.JCheckBox; 
import javax.swing.JComboBox; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JPanel; 
import javax.swing.JTextField; 

public class Sample { 

    public static void main(String[] args) { 
     JFrame frame = new JFrame("ComboBox Example"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     JCheckBox checkBox = new JCheckBox("Display Selecte Item"); 
     final JTextField text = new JTextField(""); 
     text.setEditable(false); 
     final JComboBox combo = new JComboBox(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }); 
     checkBox.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       JCheckBox check = (JCheckBox) e.getSource(); 
       if(check.isSelected()) { 
        Object obj = combo.getSelectedItem(); 
        text.setEditable(true); 
        text.requestFocus(); 
        text.setText( obj == null ? "No Item Selected" : obj.toString()); 
       } 
      } 
     }); 

     JPanel panel = new JPanel(); 
     panel.setLayout(new GridLayout(3,2)); 
     panel.add(new JLabel(" Select Item:")); 
     panel.add(combo); 
     panel.add(checkBox); 
     panel.add(new JLabel("")); 
     panel.add(new JLabel("Selected Item")); 
     panel.add(text); 

     frame.add(panel); 
     frame.pack();; 
     frame.setVisible(true); 
    } 

}