Java如何获得JComboBox的物品？
本示例演示JComboBox的getItemCount()方法的使用getItemAt(intindex)以及如何获取组合框中的项目数以及如何获取每个项目。
package org.nhooo.example.swing;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class ComboBoxGetItems extends JFrame {
public ComboBoxGetItems() {
initialize();
}
private void initialize() {
setSize(300, 300);
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
setLayout(new FlowLayout(FlowLayout.LEFT));
//创建带有等级作为值的JComboBox；
String[] items = new String[] {"A", "B", "C", "D", "E", "F"};
final JComboBox<String> gradeCombo = new JComboBox<>(items);
getContentPane().add(gradeCombo);
JButton button = new JButton("Get Items");
final JLabel label = new JLabel("Items count: ");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
//在下拉列表框中获取项目数。重复
//从零到组合框项目的数量，并获取每个项目
//指定索引的。
//
//在此示例中，我们只是将项目放置在StringBuilder中
//并稍后打印。
int count = gradeCombo.getItemCount();
StringBuilder builder = new StringBuilder();
for (int i = 0; i < count; i++) {
builder.append(gradeCombo.getItemAt(i));
if (i < count - 1) {
builder.append(", ");
}
}
label.setText("Item count: " + count + "; ["
+ builder.toString() + "]");
}
});
getContentPane().add(button);
getContentPane().add(label);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ComboBoxGetItems().setVisible(true);
}
});
}
}