Java JPOppMenu上的JMenuItems有时不是';画
我有一个JPopupMenu,当按下JButton时显示。此菜单包含一系列JMenuItems,每个项都与一个操作关联,有时会更改。我遇到的问题是,JMenuItems没有被绘制,我只是得到一个灰色的JPopupMenu,但是如果我将鼠标光标移到这些项目上,它们就会出现。我认为问题可能在于更改后没有正确地重新绘制组件,但测试表明,即使项目没有更改,问题仍然会发生。以下是相关代码:Java JPOppMenu上的JMenuItems有时不是';画,java,swing,jmenuitem,jpopupmenu,Java,Swing,Jmenuitem,Jpopupmenu,我有一个JPopupMenu,当按下JButton时显示。此菜单包含一系列JMenuItems,每个项都与一个操作关联,有时会更改。我遇到的问题是,JMenuItems没有被绘制,我只是得到一个灰色的JPopupMenu,但是如果我将鼠标光标移到这些项目上,它们就会出现。我认为问题可能在于更改后没有正确地重新绘制组件,但测试表明,即使项目没有更改,问题仍然会发生。以下是相关代码: if (!listChanged) { myPopupMenu.show(myButton,
if (!listChanged) {
myPopupMenu.show(myButton, x, y);
} else {
List<String> menuList = getMenuList();
MyData data = getData();
myPopupMenu.removeAll();
for (int i = 0; i < menuList.size(); i++) {
String name = menuList.get(i);
JMenuItem item = new JMenuItem(new MyMenuAction(this, name,
data, i));
item.addActionListener(this);
myPopupMenu.add(item);
myPopupMenu.validate();
}
myPopupMenu.repaint();
myPopupMenu.show(myButton, x, y);
}
...
private static class MyMenuAction extends AbstractAction {
private MyClass parent;
private int index;
private MyData data;
public MyMenuAction (MyClass parent, String name,
MyData data, int index) {
super(name);
this.parent = parent;
this.index = index;
this.data = data;
}
@Override
public void actionPerformed(ActionEvent e) {
Object[] actionParameters;
try {
actionParameters = data.getParameters(index);
} catch (ImmediateException e1) {
log(e1.getMessage(), "Error");
return;
}
parent.myButtonAction(actionParameters);
}
}
如果(!listChanged){
显示(我的按钮,x,y);
}否则{
List menuList=getMenuList();
MyData=getData();
myPopupMenu.removeAll();
对于(int i=0;i
只是想澄清一下,这些操作运行良好,JPopupMenu和所有JMenuItems中的10次中有8次都画对了,但我不明白为什么它们有时不出现(不管列表是否已更改)。任何帮助都将不胜感激
编辑:
好的,按照安德鲁·汤普森的建议,这里有一个简短完整的例子。许多方法已被剥离,但基本方法仍然存在。只需点击并按住“显示菜单”按钮,即可显示JPOPUP菜单。由于问题是间歇性的,因此可能需要执行多次,直到问题发生
package main;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.AbstractAction;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JToolBar;
import javax.swing.UIManager;
public class MyClass implements ActionListener, MouseListener {
boolean listChanged = true;
boolean mousePressed = false;
long clickStart;
JPopupMenu myPopupMenu;
JButton myButton;
JFrame myFrame;
ArrayList<String> list;
public static void main(String[] args) {
MyClass myClass = new MyClass();
myClass.start();
}
private void start() {
myFrame = new JFrame();
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
System.out.println(e.getClass().getName() + " " + e.getMessage());
}
startList();
myButton = new JButton("SHOW MENU");
myPopupMenu = new JPopupMenu();
JToolBar toolbar = new JToolBar();
toolbar.add(new JButton("Button1"));
toolbar.add(new JButton("Button2"));
toolbar.add(new JButton("Button3"));
toolbar.add(new JButton("Button4"));
toolbar.add(new JButton("Button5"));
toolbar.add(myButton);
myButton.addMouseListener(this);
toolbar.setBorder(BorderFactory.createEtchedBorder(1));
JPanel emptyPanel = new JPanel();
myFrame.add(toolbar, BorderLayout.PAGE_START);
myFrame.add(emptyPanel, BorderLayout.CENTER);
myFrame.pack();
myFrame.setExtendedState(myFrame.getExtendedState()
| JFrame.MAXIMIZED_BOTH);
myFrame.setVisible(true);
}
public void showMenu() {
if (!listChanged) {
myPopupMenu.show(myButton, 0, myButton.getHeight());
} else {
listChanged = false;
List<String> menuList = getMenuList();
MyData data = getData();
myPopupMenu.removeAll();
for (int i = 0; i < menuList.size(); i++) {
String name = menuList.get(i);
JMenuItem item = new JMenuItem(new MyMenuAction(this, name,
data, i));
item.addActionListener(this);
myPopupMenu.add(item);
myPopupMenu.validate();
}
myPopupMenu.repaint();
myPopupMenu.show(myButton, 0, myButton.getHeight());
}
}
private void startList() {
list = new ArrayList<String>();
list.add("Item 1");
list.add("Item 2");
list.add("Item 3");
list.add("Item 4");
list.add("Item 5");
}
private List<String> getMenuList() {
return list;
}
public void myButtonAction() {
Object[] defaultParameters = getDefaultParameters();
myButtonAction(defaultParameters);
}
private Object[] getDefaultParameters() {
// Placeholder
return null;
}
public void myButtonAction(Object[] actionParameters) {
// Placeholder
}
private MyData getData() {
// Placeholder
return new MyData();
}
private void changeList(List<String> newList) {
list.clear();
list.addAll(newList);
listChanged = true;
}
@Override
public void actionPerformed(ActionEvent e) {
// Placeholder
}
@Override
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mousePressed(MouseEvent e) {
if (e.getSource() == myButton) {
mousePressed = true;
clickStart = System.currentTimeMillis();
new Thread(new Runnable() {
@Override
public void run() {
synchronized (this) {
while (mousePressed)
try {
this.wait(10);
if (System.currentTimeMillis() - clickStart > 300) {
MyClass.this.showMenu();
return;
}
} catch (InterruptedException e1) {
break;
}
MyClass.this.myButtonAction();
}
}
}).start();
}
}
@Override
public void mouseReleased(MouseEvent e) {
mousePressed = false;
}
@Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
@Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
private static class MyData {
public Object[] getParameters(int index) {
// Placeholder
return null;
}
}
private static class MyMenuAction extends AbstractAction {
private MyClass parent;
private int index;
private MyData data;
public MyMenuAction(MyClass parent, String name, MyData data, int index) {
super(name);
this.parent = parent;
this.index = index;
this.data = data;
}
@Override
public void actionPerformed(ActionEvent e) {
Object[] actionParameters;
try {
actionParameters = data.getParameters(index);
} catch (Exception e1) {
System.out.println(e1.getMessage());
return;
}
parent.myButtonAction(actionParameters);
}
}
}
packagemain;
导入java.awt.BorderLayout;
导入java.awt.event.ActionEvent;
导入java.awt.event.ActionListener;
导入java.awt.event.MouseEvent;
导入java.awt.event.MouseListener;
导入java.util.ArrayList;
导入java.util.List;
导入javax.swing.AbstractAction;
导入javax.swing.BorderFactory;
导入javax.swing.JButton;
导入javax.swing.JFrame;
导入javax.swing.JMenuItem;
导入javax.swing.JPanel;
导入javax.swing.jpopmenu;
导入javax.swing.JToolBar;
导入javax.swing.UIManager;
公共类MyClass实现ActionListener、MouseListener{
布尔listChanged=true;
布尔mousePressed=false;
长点击开始;
JPOppMenu myPopupMenu;
JButton-myButton;
JFrame-myFrame;
数组列表;
公共静态void main(字符串[]args){
MyClass MyClass=新的MyClass();
myClass.start();
}
私有void start(){
myFrame=newjframe();
myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
试一试{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}捕获(例外e){
System.out.println(e.getClass().getName()+“”+e.getMessage());
}
惊吓者();
myButton=新的JButton(“显示菜单”);
myPopupMenu=新的JPopupMenu();
JToolBar toolbar=新的JToolBar();
添加(新的JButton(“Button1”);
添加(新的JButton(“Button2”);
添加(新的JButton(“Button3”);
添加(新的JButton(“Button4”);
添加(新的JButton(“Button5”);
工具栏.添加(myButton);
myButton.addMouseListener(这个);
toolbar.setOrder(BorderFactory.createEtchedBorder(1));
JPanel emptyPanel=新的JPanel();
myFrame.add(工具栏、边框布局、页面开始);
添加(emptyPanel,BorderLayout.CENTER);
myFrame.pack();
myFrame.setExtendedState(myFrame.getExtendedState())
|JFrame.MAXIMIZED_两者);
myFrame.setVisible(true);
}
公共void showMenu(){
如果(!listChanged){
显示(myButton,0,myButton.getHeight());
}否则{
listChanged=false;
List menuList=getMenuList();
MyData=getData();
myPopupMenu.removeAll();
对于(int i=0;i