Java 如何设置JComboBox项的边框

我想在我的应用程序中创建一个默认JComboBox。但是我在设置JComboBox项的边界时遇到了一个小问题

这是JComboBox

package test.combobox;

import java.awt.Color;
import java.awt.Font;
import javax.swing.JComboBox;

public class MyComboBox extends JComboBox<Object> {
    public MyComboBox() {
        super();

        setBackground(new Color(0xFFFFFF));
        setFont(new Font("Tahoma", 0, 14));
    }
}

测试组合框

package test.combobox;

import java.awt.Dimension;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JFrame;
import javax.swing.UIManager;
import net.sf.jasperreports.engine.JRException;

public class TestComboBox {
    public static void main(String[] args) throws JRException {

        UIManager.getCrossPlatformLookAndFeelClassName(); 

        JFrame frame = new JFrame("MyComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(new Dimension(300, 70));

        MyComboBox cb = new MyComboBox();
        cb.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
        cb.setPreferredSize(new Dimension(300, 30));

        frame.getContentPane().add(cb);
        frame.pack();
        frame.setVisible(true);
    }
}

---

JComboBox

中的项目通过界面呈现

请看和以获取示例

这是一个重要的概念，因为

JTable

，

JTree

和

JList

也使用这个概念

package test.combobox;

import java.awt.Dimension;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JFrame;
import javax.swing.UIManager;
import net.sf.jasperreports.engine.JRException;

public class TestComboBox {
    public static void main(String[] args) throws JRException {

        UIManager.getCrossPlatformLookAndFeelClassName(); 

        JFrame frame = new JFrame("MyComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(new Dimension(300, 70));

        MyComboBox cb = new MyComboBox();
        cb.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
        cb.setPreferredSize(new Dimension(300, 30));

        frame.getContentPane().add(cb);
        frame.pack();
        frame.setVisible(true);
    }
}