Java JPanel#设置可见不工作。
我在使用Netbeans查看JPanel时遇到了问题;我举了一个简单的例子来说明发生了什么。 Netbeans在我设计组合和面板时创建代码->直到“private void TheFrame(java.awt.event.WindowEvent evt)” 我把panelOne(JPanel).setVisible(false)和 这管用! 在从组合中选择一个项目(item2/item4)之后,我希望显示panelOne,但这不起作用Java JPanel#设置可见不工作。,java,swing,netbeans,jpanel,Java,Swing,Netbeans,Jpanel,我在使用Netbeans查看JPanel时遇到了问题;我举了一个简单的例子来说明发生了什么。 Netbeans在我设计组合和面板时创建代码->直到“private void TheFrame(java.awt.event.WindowEvent evt)” 我把panelOne(JPanel).setVisible(false)和 这管用! 在从组合中选择一个项目(item2/item4)之后,我希望显示panelOne,但这不起作用 /** * * @author Alessandro
/**
*
* @author Alessandro
*/
public class UIFrame extends javax.swing.JFrame {
/**
* Creates new form UIFrame
*/
public UIFrame() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
panelOne = new javax.swing.JPanel();
comboBox = new javax.swing.JComboBox();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
addWindowListener(new java.awt.event.WindowAdapter() {
public void windowActivated(java.awt.event.WindowEvent evt) {
TheFrame(evt);
}
});
javax.swing.GroupLayout panelOneLayout = new javax.swing.GroupLayout(panelOne);
panelOne.setLayout(panelOneLayout);
panelOneLayout.setHorizontalGroup(
panelOneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 349, Short.MAX_VALUE)
);
panelOneLayout.setVerticalGroup(
panelOneLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 52, Short.MAX_VALUE)
);
comboBox.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
comboBox.addItemListener(new java.awt.event.ItemListener() {
public void itemStateChanged(java.awt.event.ItemEvent evt) {
ItemListener(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(30, 30, 30)
.addComponent(panelOne, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(122, 122, 122)
.addComponent(comboBox, javax.swing.GroupLayout.PREFERRED_SIZE, 143, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addContainerGap(21, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(comboBox, javax.swing.GroupLayout.PREFERRED_SIZE, 29, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(33, 33, 33)
.addComponent(panelOne, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(175, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void TheFrame(java.awt.event.WindowEvent evt) {
panelOne.setVisible(false);
}
private void ItemListener(java.awt.event.ItemEvent evt) {
String test = (String)(evt.getItem());
switch (test)
{
case "Item1":
panelOne.setVisible(false);
case "Item2":
panelOne.setVisible(true);
case "Item3":
panelOne.setVisible(false);
case "Item4":
panelOne.setVisible(true);
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new UIFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JComboBox comboBox;
private javax.swing.JPanel panelOne;
// End of variables declaration
}
/**
*
*@作者亚历山德罗
*/
公共类UIFrame扩展了javax.swing.JFrame{
/**
*创建新表单UIFrame
*/
公共UIFrame(){
初始化组件();
}
/**
*从构造函数中调用此方法来初始化表单。
*警告:不要修改此代码。此方法的内容始终为
*由表单编辑器重新生成。
*/
@抑制警告(“未选中”)
//
私有组件(){
panelOne=newjavax.swing.JPanel();
comboBox=newjavax.swing.JComboBox();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
addWindowListener(新java.awt.event.WindowAdapter(){
public void windowActivated(java.awt.event.WindowEvent evt){
帧(evt);
}
});
javax.swing.GroupLayout panelOneLayout=新的javax.swing.GroupLayout(panelOne);
panelOne.setLayout(panelOneLayout);
panelOneLayout.setHorizontalGroup(
createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0,349,短。最大值)
);
panelOneLayout.setVerticalGroup(
createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0,52,短。最大值)
);
setModel(新的javax.swing.DefaultComboxModel(新字符串[]{“Item 1”、“Item 2”、“Item 3”、“Item 4”});
comboBox.addItemListener(新java.awt.event.ItemListener(){
public void itemStateChanged(java.awt.event.ItemEvent evt){
项目监听器(evt);
}
});
javax.swing.GroupLayout=newjavax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(布局);
layout.setHorizontalGroup(
createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(30,30,30)
.addComponent(panelOne,javax.swing.GroupLayout.PREFERRED\u SIZE,javax.swing.GroupLayout.DEFAULT\u SIZE,javax.swing.GroupLayout.PREFERRED\u SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(122、122、122)
.addComponent(组合框,javax.swing.GroupLayout.PREFERRED\u SIZE,143,javax.swing.GroupLayout.PREFERRED\u SIZE)))
.addContainerGap(21,简称最大值))
);
layout.setVerticalGroup(
createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(组合框,javax.swing.GroupLayout.PREFERRED\u SIZE,29,javax.swing.GroupLayout.PREFERRED\u SIZE)
.addGap(33,33,33)
.addComponent(panelOne,javax.swing.GroupLayout.PREFERRED\u SIZE,javax.swing.GroupLayout.DEFAULT\u SIZE,javax.swing.GroupLayout.PREFERRED\u SIZE)
.addContainerGap(175,简称最大值))
);
包装();
}//
私有无效帧(java.awt.event.WindowEvent evt){
panelOne.setVisible(假);
}
私有void ItemListener(java.awt.event.ItemEvent evt){
字符串测试=(字符串)(evt.getItem());
开关(测试)
{
案例“项目1”:
panelOne.setVisible(假);
案例“项目2”:
panelOne.setVisible(真);
案例“项目3”:
panelOne.setVisible(假);
案例“项目4”:
panelOne.setVisible(真);
}
}
/**
*@param指定命令行参数
*/
公共静态void main(字符串参数[]){
/*设置Nimbus的外观和感觉*/
//
/*如果Nimbus(在JavaSE6中引入)不可用,请使用默认的外观。
*详情请参阅http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
试一试{
for(javax.swing.UIManager.LookAndFeelInfo:javax.swing.UIManager.getInstalledLookAndFeels()){
if(“Nimbus”.equals(info.getName())){
setLookAndFeel(info.getClassName());
打破
}
}
}捕获(ClassNotFoundException ex){
getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE,null,ex);
}catch(实例化异常){
getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE,null,ex);
}捕获(非法访问例外){
getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE,null,ex);
}catch(javax.swing.UnsupportedLookAndFeelException ex){
getLogger(UIFrame.class.getName()).log(java.util.logging.Level.SEVERE,null,ex);
}
//
/*创建并显示表单*/
invokeLater(new Runnable()){
普布利
"Item 1", "Item 2", "Item 3" and "Item 4"
"item1", "item2", "item3" and "item4"
private void ItemListener(java.awt.event.ItemEvent evt) {
String test = (String) (evt.getItem()); //do not use this
System.out.println(test);
JComboBox box = (JComboBox)evt.getSource();
String selectedString = (String) box.getSelectedItem();
switch (selectedString) { //replaced test with selectedString
case "Item 1":
panelOne.setVisible(false); break;
case "Item 2":
panelOne.setVisible(true); break;
case "Item 3":
panelOne.setVisible(false); break;
case "Item 4":
panelOne.setVisible(true); break;
}
}
switch(var){
case 1: doOne();
case 2: doTwo();
case 3: doThree();
}
switch(var){
case 1: doOne(); break;
case 2: doTwo(); break;
case 3: doThree(); break;
}
import java.awt.BorderLayout;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class UIFrame extends JFrame {
final private JPanel panelOne = new JPanel();
private JComboBox comboBox;
public UIFrame() {
initComponents();
}
private void initComponents() {
setLayout(new BorderLayout());
comboBox = new javax.swing.JComboBox();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
comboBox.setModel(new javax.swing.DefaultComboBoxModel(new String[] {
"Item 1", "Item 2", "Item 3", "Item 4" }));
comboBox.addItemListener(new java.awt.event.ItemListener() {
public void itemStateChanged(java.awt.event.ItemEvent evt) {
ItemListener(evt);
}
});
panelOne.add(new JTextField("Hello"));
add(comboBox, BorderLayout.CENTER);
add(panelOne, BorderLayout.NORTH);
}
private void ItemListener(java.awt.event.ItemEvent evt) {
panelOne.setVisible(false);
String test = (String) (evt.getItem());
System.out.println(test);
JComboBox box = (JComboBox)evt.getSource();
String selectedString = (String) box.getSelectedItem();
switch (selectedString) {
case "Item 1":
panelOne.setVisible(false);
break;
case "Item 2":
panelOne.setVisible(true);
break;
case "Item 3":
panelOne.setVisible(false);
break;
case "Item 4":
panelOne.setVisible(true);
break;
}
}
public static void main(String[] args) {
final UIFrame frame = new UIFrame();
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
frame.pack();
frame.setVisible(true);
}
});
}
}
private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {
PanelChange();
}
private void PanelChange() {
String test = jComboBox1.getSelectedItem().toString();
if (test.equals("Item 1") || test.equals("Item 3")) {
jPanel1.setVisible(false);
}else{
jPanel1.setVisible(true);
}
}
public UIFrame() {
initComponents();
PanelChange();
}