java中怎么实现横向列表框

实现方法如下:

?1.在一级ul列表内建立一级li元素并清除默认样式。

?2.让所有一级li元素左浮动并清除浮动。

?3.在一级li内创建二级ul列表，二级ul列表内建立二级li元素并清除默认样式。

?4.设置二级ul列表属性display:none让此元素不会被显示。

?5.在JS内动态设置一级li元素被点击时，让其下的二级ul列表属性切换为display:block让此元素显示。

Java程序：

import java.awt.*

import java.awt.event.ItemEvent

import java.awt.event.ItemListener

import javax.swing.*

public class Main extends JFrame implements ItemListener {

JComboBox cmbProvince, cmbCity

JTextField txtProvince, txtCity

String[] provinces = {"请选择省份", "北京市", "上海市", "河南省"}

String[][] cities = {{"东城区", "西城区", "海淀区", "丰台区"}, {"浦东区", "徐汇区", "崇明县"}, {"郑州市", "洛阳市", "开封市"}}

public Main() {

super("请选择省份/城市")

this.setSize(350, 200)

this.setVisible(true)

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE)

this.setLayout(new FlowLayout())

init()

}

public void init() {

cmbProvince = new JComboBox(provinces)

cmbCity = new JComboBox(new String[]{"请选择城市"})

txtProvince = new JTextField(15)

txtCity = new JTextField(15)

this.add(cmbProvince)

this.add(txtProvince)

this.add(cmbCity)

this.add(txtCity)

cmbProvince.addItemListener(this)

cmbCity.addItemListener(this)

}

public static void main(String[] args) {

new Main()

}

@Override

public void itemStateChanged(ItemEvent arg0) {

if(arg0.getStateChange() != ItemEvent.SELECTED){

return

}

JComboBox cmb = (JComboBox) arg0.getSource()

int i

int index

if(cmb == cmbProvince) {

index = cmbProvince.getSelectedIndex()

if(index == 0) {

return

}

cmbCity.removeAllItems()

cmbCity.addItem("请选择城市")

for(i=0 i<cities[index-1].length i++) {

cmbCity.addItem(cities[index-1][i])

}

txtProvince.setText("您选择的省份是：" + cmbProvince.getSelectedItem().toString())

}

else if(cmb == cmbCity) {

index = cmbCity.getSelectedIndex()

if(index == 0) {

return

}

txtCity.setText("您选择的城市是：" + cmb.getSelectedItem().toString())

}

}

}

运行测试：

package test

import java.awt.event.ActionEvent

import java.awt.event.ActionListener

import javax.swing.DefaultListModel

import javax.swing.JButton

import javax.swing.JList

import javax.swing.WindowConstants

public class ListFrame extends javax.swing.JFrame {

private JList jList1

private JButton jButton1

private JButton jButton2

private JList jList2

private DefaultListModel listModel1

private DefaultListModel listModel2

private JButton jButton4

private JButton jButton3

{

//Set Look &Feel

try {

javax.swing.UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel")

} catch(Exception e) {

e.printStackTrace()

}

}

/**

* Auto-generated main method to display this JFrame

*/

public static void main(String[] args) {

ListFrame inst = new ListFrame()

inst.setVisible(true)

}

public ListFrame() {

super()

initGUI()

}

private void initGUI() {

try {

setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE)

getContentPane().setLayout(null)

{

listModel1 = new DefaultListModel()

listModel1.addElement("item 1")

listModel1.addElement("item 2")

listModel1.addElement("item 3")

listModel1.addElement("item 4")

listModel1.addElement("item 5")

listModel1.addElement("item 6")

jList1 = new JList(listModel1)

getContentPane().add(jList1)

jList1.setBounds(42, 28, 119, 203)

}

{

listModel2 = new DefaultListModel()

jList2 = new JList(listModel2)

getContentPane().add(jList2)

jList2.setBounds(238, 28, 119, 196)

}

{

jButton1 = new JButton()

getContentPane().add(jButton1)

jButton1.setText(">")

jButton1.setBounds(168, 84, 63, 28)

jButton1.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent evt) {

jButton1ActionPerformed(evt)

}

})

}

{

jButton2 = new JButton()

getContentPane().add(jButton2)

jButton2.setText("<")

jButton2.setBounds(168, 133, 63, 28)

jButton2.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent evt) {

jButton2ActionPerformed(evt)

}

})

}

{

jButton3 = new JButton()

getContentPane().add(jButton3)

jButton3.setText("添加")

jButton3.setBounds(168, 35, 63, 28)

jButton3.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent evt) {

jButton3ActionPerformed(evt)

}

})

}

{

jButton4 = new JButton()

getContentPane().add(jButton4)

jButton4.setText("删除")

jButton4.setBounds(168, 189, 63, 28)

jButton4.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent evt) {

jButton4ActionPerformed(evt)

}

})

}

pack()

setSize(400, 300)

setLocationRelativeTo(null)

} catch (Exception e) {

e.printStackTrace()

}

}

/** jList1移动到jList2*/

private void jButton1ActionPerformed(ActionEvent evt) {

if(jList1.getSelectedIndex()!=-1){

listModel2.addElement(jList1.getSelectedValue())

int i=jList1.getSelectedIndex()

listModel1.remove(i)

jList1.setSelectedIndex(i>0? i-1:0)

jList2.setSelectedIndex(listModel2.size()-1)

}

}

/** jList2移动到jList1*/

private void jButton2ActionPerformed(ActionEvent evt) {

if(jList2.getSelectedIndex()!=-1){

listModel1.addElement(jList2.getSelectedValue())

int i=jList2.getSelectedIndex()

listModel2.remove(i)

jList2.setSelectedIndex(i>0? i-1:0)

}

}

/** jList1增加项*/

private void jButton3ActionPerformed(ActionEvent evt) {

listModel1.addElement("new item")

}

/** jList1删除项*/

private void jButton4ActionPerformed(ActionEvent evt) {

if(jList1.getSelectedIndex()!=-1){

listModel1.remove(jList1.getSelectedIndex())

}

}

}

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