swing 下拉菜单

package rom;

import java.lang.*;

import javax.swing.BorderFactory;

import javax.swing.ButtonGroup;

import javax.swing.JButton;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JRadioButton;

import javax.swing.WindowConstants;

import javax.swing.border.BevelBorder;

import javax.swing.plaf.BorderUIResource;

import java.awt.*;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

public class Xamle_4 extends JFrame{

	public Xamle_4(String name) {

		JFrame jf =new JFrame(name);

		Container container = jf.getContentPane();

		jf.setLayout(null);

		//container.setLayout(new GridLayout(2, 1,10,10)); //设置布局方式

		JPanel p1 = new JPanel();

		JPanel p2 = new JPanel();

		JPanel p3 = new JPanel();

		JPanel p4 = new JPanel();

		JPanel p5 = new JPanel();

		JPanel p6 = new JPanel();

		String [] strings = {"菠萝","香蕉","苹果","哈密瓜","西瓜"}; //创建下拉菜单栏的信息

		JComboBox<String> jComboBox  = new JComboBox<>(strings); //创建下拉菜单栏

		jComboBox.addItemListener(new ItemListener() { //点击下拉多选菜单的监控

			@Override

			public void itemStateChanged(ItemEvent e) {

				if (e.getStateChange()==ItemEvent.SELECTED) { //选择点击

					System.out.println("你选择的是：");

				}

				if(jComboBox.getSelectedItem().equals("菠萝")) {

					System.out.println("菠萝");

				}

				if(jComboBox.getSelectedItem().equals("香蕉")) {

					System.out.println("香蕉");

				}

				if(jComboBox.getSelectedItem().equals("苹果")) {

					System.out.println("苹果");

				}

				if(jComboBox.getSelectedItem().equals("哈密瓜")) {

					System.out.println("哈密瓜");

				}

				if(jComboBox.getSelectedItem().equals("西瓜")) {

					System.out.println("西瓜");

				}

				// TODO Auto-generated method stub

			}

		});

		JRadioButton jr1 = new JRadioButton("按键1"); //添加单选按键

		JRadioButton jr2 = new JRadioButton("按键2"); //添加单选按键

		// p1.setPreferredSize(new Dimension(150, 150));  //设置Jpanel 首选大小 ，Dimension是尺子工具的意思 面板大小

		// p2.setPreferredSize(new Dimension(150, 150)); //设置JPanel 面板大小

		ButtonGroup group = new ButtonGroup();   //创建单选按键集合

		p1.setBorder(BorderFactory.createTitledBorder("选择框边框")); //设置P1面板的边界显示方式，此方式为标题边框  //BorderFactory 是边界工具的意思

		p2.setBorder(BorderFactory.createEmptyBorder());  //创建空白边框

		p3.setBorder(BorderFactory.createLineBorder(Color.BLUE)); //创建线边框 (选择蓝色)

		p4.setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED)); //创建凸起效果边框

		p5.setBorder(BorderFactory.createMatteBorder(20, 20, 20, 20, Color.yellow)); //创建带厚度和颜色的边框

		p6.setBorder(BorderFactory.createSoftBevelBorder(BevelBorder.LOWERED)); //创建带凹面效果的边框

		p1.setBounds(1, 1, 200, 200);  //设置p1 面板的位置和大小

		p2.setBounds(201, 1, 200, 200); //设置p2 面板的位置和大小

		p3.setBounds(402, 1, 200, 200);

		p4.setBounds(1, 201, 200, 200);

		p5.setBounds(201, 201, 200, 200);

		p6.setBounds(402, 201, 200, 200);

		group.add(jr1); //将单选按钮添加到一个组合中

		group.add(jr2);

		p1.add(jr1);

		p1.add(jr2);

		p2.add(new JButton("1"));//创建一个按钮

		p3.add(new JButton("2"));

		p4.add(new JButton("3"));

		p5.add(jComboBox); //将下拉菜单添加到面板里

		container.add(p1);

		container.add(p2);

		container.add(p3);

		container.add(p4);

		container.add(p5);

		container.add(p6);

		jf.setVisible(true); //将框体可视

		jf.setSize(630, 500); //宽 和 高

		setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE); //设置关闭方式

	}

	public static void main(String [] agrs) {

		new Xamle_4("单选按键测试");

	}

}