我是Java的新手。我有关于获取JInternalFrame的问题。我在网上搜索并找到了例子。我稍微修改了一下这个例子,添加了一个close menuitem,但它并没有使用我的代码。在项目中如果我关闭JInternalFrame而不先选择它,那么我就有错误。我试图遍历WindowMenu以获取所选的JcheckboxMenuitem,但它没有获得任何组件。有人会告诉我该怎么做。
有代码:
// This is example is from Kjell Dirdal.
// Referenced from http://www.javaworld.com/javaworld/jw-05-2001/jw-0525-mdi.html
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.PropertyVetoException;
import javax.swing.DefaultDesktopManager;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JComponent;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JViewport;
import javax.swing.event.MenuEvent;
import javax.swing.event.MenuListener;
public class KjellDirdalNotepad extends JFrame {
private MDIDesktopPane desktop = new MDIDesktopPane();
private JMenuBar menuBar = new JMenuBar();
private JMenu fileMenu = new JMenu("File");
private JMenuItem newMenu = new JMenuItem("New");
private JScrollPane scrollPane = new JScrollPane();
private JMenuItem closeMenu=new JMenuItem("Close");
private int index=1;
private WindowMenu wMenu=null;
public KjellDirdalNotepad() {
menuBar.add(fileMenu);
wMenu=new WindowMenu(desktop);
menuBar.add(wMenu);
fileMenu.add(newMenu);
fileMenu.add(closeMenu);
setJMenuBar(menuBar);
setTitle("MDI Test");
scrollPane.getViewport().add(desktop);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(scrollPane, BorderLayout.CENTER);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
newMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
desktop.add(new TextFrame(String.valueOf(index)));
index=index+1;
}
});
//I added the close menu
closeMenu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
JInternalFrame f=desktop.getSelectedFrame();
if (f==null)
{
for (Component child: wMenu.getComponents()){
if (child instanceof WindowMenu.ChildMenuItem){
JCheckBoxMenuItem item=(JCheckBoxMenuItem) child;
if( item.isSelected()){
DisplayTestMsg(item.getText());
}
}
}
}
else{
f.dispose();
}
}
});
}
public void DisplayTestMsg(String msg){
//custom title, error icon
JTextArea textArea=new JTextArea(msg);
textArea.setColumns(30);
textArea.setLineWrap( true );
textArea.setWrapStyleWord( true );
textArea.setSize(textArea.getPreferredSize().width, 1);
JOptionPane.showMessageDialog(null,
textArea,
"Test",
JOptionPane.WARNING_MESSAGE);
}
public static void main(String[] args) {
KjellDirdalNotepad notepad = new KjellDirdalNotepad();
notepad.setSize(600, 400);
notepad.setVisible(true);
}
}
class TextFrame extends JInternalFrame {
private JTextArea textArea = new JTextArea();
private JScrollPane scrollPane = new JScrollPane();
public TextFrame(String title) {
setSize(200, 300);
setTitle("Edit Text-" + title);
setMaximizable(true);
setIconifiable(true);
setClosable(true);
setResizable(true);
scrollPane.getViewport().add(textArea);
getContentPane().setLayout(new BorderLayout());
getContentPane().add(scrollPane, BorderLayout.CENTER);
}
}
/**
* An extension of WDesktopPane that supports often used MDI functionality. This
* class also handles setting scroll bars for when windows move too far to the
* left or bottom, providing the MDIDesktopPane is in a ScrollPane.
*/
class MDIDesktopPane extends JDesktopPane {
private static int FRAME_OFFSET = 20;
private MDIDesktopManager manager;
public MDIDesktopPane() {
manager = new MDIDesktopManager(this);
setDesktopManager(manager);
setDragMode(JDesktopPane.OUTLINE_DRAG_MODE);
}
public void setBounds(int x, int y, int w, int h) {
super.setBounds(x, y, w, h);
checkDesktopSize();
}
public Component add(JInternalFrame frame) {
JInternalFrame[] array = getAllFrames();
Point p;
int w;
int h;
Component retval = super.add(frame);
checkDesktopSize();
if (array.length > 0) {
p = array[0].getLocation();
p.x = p.x + FRAME_OFFSET;
p.y = p.y + FRAME_OFFSET;
} else {
p = new Point(0, 0);
}
frame.setLocation(p.x, p.y);
if (frame.isResizable()) {
w = getWidth() - (getWidth() / 3);
h = getHeight() - (getHeight() / 3);
if (w < frame.getMinimumSize().getWidth())
w = (int) frame.getMinimumSize().getWidth();
if (h < frame.getMinimumSize().getHeight())
h = (int) frame.getMinimumSize().getHeight();
frame.setSize(w, h);
}
moveToFront(frame);
frame.setVisible(true);
try {
frame.setSelected(true);
} catch (PropertyVetoException e) {
frame.toBack();
}
return retval;
}
public void remove(Component c) {
super.remove(c);
checkDesktopSize();
}
/**
* Cascade all internal frames
*/
public void cascadeFrames() {
int x = 0;
int y = 0;
JInternalFrame allFrames[] = getAllFrames();
manager.setNormalSize();
int frameHeight = (getBounds().height - 5) - allFrames.length * FRAME_OFFSET;
int frameWidth = (getBounds().width - 5) - allFrames.length * FRAME_OFFSET;
for (int i = allFrames.length - 1; i >= 0; i--) {
allFrames[i].setSize(frameWidth, frameHeight);
allFrames[i].setLocation(x, y);
x = x + FRAME_OFFSET;
y = y + FRAME_OFFSET;
}
}
/**
* Tile all internal frames
*/
public void tileFrames() {
java.awt.Component allFrames[] = getAllFrames();
manager.setNormalSize();
int frameHeight = getBounds().height / allFrames.length;
int y = 0;
for (int i = 0; i < allFrames.length; i++) {
allFrames[i].setSize(getBounds().width, frameHeight);
allFrames[i].setLocation(0, y);
y = y + frameHeight;
}
}
/**
* Sets all component size properties ( maximum, minimum, preferred) to the
* given dimension.
*/
public void setAllSize(Dimension d) {
setMinimumSize(d);
setMaximumSize(d);
setPreferredSize(d);
}
/**
* Sets all component size properties ( maximum, minimum, preferred) to the
* given width and height.
*/
public void setAllSize(int width, int height) {
setAllSize(new Dimension(width, height));
}
private void checkDesktopSize() {
if (getParent() != null && isVisible())
manager.resizeDesktop();
}
}
/**
* Private class used to replace the standard DesktopManager for JDesktopPane.
* Used to provide scrollbar functionality.
*/
class MDIDesktopManager extends DefaultDesktopManager {
private MDIDesktopPane desktop;
public MDIDesktopManager(MDIDesktopPane desktop) {
this.desktop = desktop;
}
public void endResizingFrame(JComponent f) {
super.endResizingFrame(f);
resizeDesktop();
}
public void endDraggingFrame(JComponent f) {
super.endDraggingFrame(f);
resizeDesktop();
}
public void setNormalSize() {
JScrollPane scrollPane = getScrollPane();
int x = 0;
int y = 0;
Insets scrollInsets = getScrollPaneInsets();
if (scrollPane != null) {
Dimension d = scrollPane.getVisibleRect().getSize();
if (scrollPane.getBorder() != null) {
d.setSize(d.getWidth() - scrollInsets.left - scrollInsets.right, d.getHeight()
- scrollInsets.top - scrollInsets.bottom);
}
d.setSize(d.getWidth() - 20, d.getHeight() - 20);
desktop.setAllSize(x, y);
scrollPane.invalidate();
scrollPane.validate();
}
}
private Insets getScrollPaneInsets() {
JScrollPane scrollPane = getScrollPane();
if (scrollPane == null)
return new Insets(0, 0, 0, 0);
else
return getScrollPane().getBorder().getBorderInsets(scrollPane);
}
private JScrollPane getScrollPane() {
if (desktop.getParent() instanceof JViewport) {
JViewport viewPort = (JViewport) desktop.getParent();
if (viewPort.getParent() instanceof JScrollPane)
return (JScrollPane) viewPort.getParent();
}
return null;
}
protected void resizeDesktop() {
int x = 0;
int y = 0;
JScrollPane scrollPane = getScrollPane();
Insets scrollInsets = getScrollPaneInsets();
if (scrollPane != null) {
JInternalFrame allFrames[] = desktop.getAllFrames();
for (int i = 0; i < allFrames.length; i++) {
if (allFrames[i].getX() + allFrames[i].getWidth() > x) {
x = allFrames[i].getX() + allFrames[i].getWidth();
}
if (allFrames[i].getY() + allFrames[i].getHeight() > y) {
y = allFrames[i].getY() + allFrames[i].getHeight();
}
}
Dimension d = scrollPane.getVisibleRect().getSize();
if (scrollPane.getBorder() != null) {
d.setSize(d.getWidth() - scrollInsets.left - scrollInsets.right, d.getHeight()
- scrollInsets.top - scrollInsets.bottom);
}
if (x <= d.getWidth())
x = ((int) d.getWidth()) - 20;
if (y <= d.getHeight())
y = ((int) d.getHeight()) - 20;
desktop.setAllSize(x, y);
scrollPane.invalidate();
scrollPane.validate();
}
}
}
/**
* Menu component that handles the functionality expected of a standard
* "Windows" menu for MDI applications.
*/
class WindowMenu extends JMenu {
private MDIDesktopPane desktop;
private JMenuItem cascade = new JMenuItem("Cascade");
private JMenuItem tile = new JMenuItem("Tile");
public WindowMenu(MDIDesktopPane desktop) {
this.desktop = desktop;
setText("Window");
cascade.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
WindowMenu.this.desktop.cascadeFrames();
}
});
tile.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
WindowMenu.this.desktop.tileFrames();
}
});
addMenuListener(new MenuListener() {
public void menuCanceled(MenuEvent e) {
}
public void menuDeselected(MenuEvent e) {
removeAll();
}
public void menuSelected(MenuEvent e) {
buildChildMenus();
}
});
}
/* Sets up the children menus depending on the current desktop state */
private void buildChildMenus() {
int i;
ChildMenuItem menu;
JInternalFrame[] array = desktop.getAllFrames();
add(cascade);
add(tile);
if (array.length > 0)
addSeparator();
cascade.setEnabled(array.length > 0);
tile.setEnabled(array.length > 0);
for (i = 0; i < array.length; i++) {
menu = new ChildMenuItem(array[i]);
menu.setState(i == 0);
menu.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
JInternalFrame frame = ((ChildMenuItem) ae.getSource()).getFrame();
frame.moveToFront();
try {
frame.setSelected(true);
} catch (PropertyVetoException e) {
e.printStackTrace();
}
}
});
menu.setIcon(array[i].getFrameIcon());
add(menu);
}
}
/*
* This JCheckBoxMenuItem descendant is used to track the child frame that
* corresponds to a give menu.
*/
class ChildMenuItem extends JCheckBoxMenuItem {
private JInternalFrame frame;
public ChildMenuItem(JInternalFrame frame) {
super(frame.getTitle());
this.frame = frame;
}
public JInternalFrame getFrame() {
return frame;
}
}
}
答案 0 :(得分:0)
如果要在按下按钮时删除JPanel,可以调用JFrame.remove(面板),例如:
final JFrame frame = new JFrame("test");
final JPanel panel = new JPanel();
//add the panel at the start
frame.add(panel);
// when the buttons clicked
button.addActionListener(new ActionListener() {
@Override
public void ActionPerformed(ActionEvent e) {
frame.remove(panel);
frame.repaint();
};
});
答案 1 :(得分:0)
我明白了。我在Class WindowMenu上添加了方法,如下所示。单击关闭按钮而没有选择内部框架时,将调用此方法。
public JInternalFrame getFrontFrame(){
InternalFrame[] array = desktop.getAllFrames();
JInternalFrame f=(JInternalFrame)array[0];
return f;
}