📄 popupcursel.htm
字号:
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<TITLE>Getting the Currently Selected Menu or Menu Item (Java Developers Almanac Example)
</TITLE>
<META CONTENT="Patrick Chan" NAME="AUTHOR">
<META CONTENT="Code Examples from The Java Developers Almanac 1.4" NAME="DESCRIPTION">
<META CONTENT="Addison-Wesley/Patrick Chan" NAME="OWNER">
<META CONTENT="3/20/02" NAME="revision">
<META CONTENT="no-cache" HTTP-EQUIV="Pragma">
<LINK href="/almanac.css" media="screen" type="text/css" rel="stylesheet">
</HEAD>
<BODY>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD></TD>
</TR>
</TABLE>
<br>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD></TD>
</TR>
<TR>
<TD rowspan="3"><A HREF="/?l=ex"><IMG BORDER="0" ALIGN="BOTTOM" HSPACE="10" SRC="/egs/almanac14a.jpg"></A></TD><TD VALIGN="top">
<h1>The Java Developers Almanac 1.4</h1>
<br>
Order this book from <a href="/cgi-bin/scripts/redirect.pl?l=ex&url=http://www.amazon.com/exec/obidos/ASIN/0201752808/xeo">Amazon</a>.
</TD>
</TR>
<TR>
<TD align="right" valign="bottom">
<FORM method="get" action="/cgi-bin/search/find.pl">
<INPUT size="25" name="words" type="text"><INPUT value="Search" type="submit">
</FORM>
</TD>
</TR>
</TABLE>
<HR color="#6666cc">
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD valign="top"><script type="text/javascript">
<!--
google_ad_client = "pub-6001183370374757";
google_ad_width = 120;
google_ad_height = 600;
google_ad_format = "120x600_as";
google_ad_channel = "4777242811";
google_ad_type = "text_image";
google_color_border = "FFFFFF";
google_color_bg = "FFFFFF";
google_color_link = "6666CC";
google_color_url = "6666CC";
google_color_text = "000000";
//--></script><script src="http://pagead2.googlesyndication.com/pagead/show_ads.js" type="text/javascript"></script></TD><TD> </TD><TD valign="top">
<DIV ALIGN="LEFT">
<A HREF="/">Home</A>
>
<A HREF="../index.html">List of Packages</A>
>
<A HREF="../javax.swing/pkg.html">javax.swing</A><font color="#666666" class="xsmall-font">
[141 examples]
</font>
>
<B><A HREF="../javax.swing/pkg.html#Menus">Menus</A></B><font color="#666666" class="xsmall-font">
[8 examples]
</font>
</DIV><P>
<h3>e813. Getting the Currently Selected Menu or Menu Item</h3>
The currently selected menu or menu item in a <code>JMenu</code> or
<code>JPopupMenu</code> is tracked by <code>MenuSelectionManager</code> and can be
retrieved by calling <code>MenuSelectionManager.getSelectedPath()</code>.
This method returns an array of <code>MenuElement</code> objects, representing
all the menu objects that are part of the selected menu or menu item.
For example, when a menu is opened in a menu bar, the sequence of
elements in the path is: <code>JMenuBar</code>, <code>JMenu</code>, and
<code>JPopupMenu</code>. If a menu item in the open menu is then selected,
there will be fourth element, a <code>JMenuItem</code>.
<P> The menu path also includes nested menus. For example, if the
currently selected menu item is part of a nested menu in a menu bar,
the sequence of elements is: <code>JMenuBar</code>, <code>JMenu</code>,
<code>JPopupMenu</code>, <code>JMenu</code>, <code>JPopupMenu</code>, and <code>JMenuItem</code>.
Note that a <code>JMenu</code> is always followed by a <code>JPopupMenu</code>.
<P> If a menu item in a popup menu is selected, the sequence of
menu objects is simply <code>JPopupMenu</code> and <code>JMenuItem</code>.
If the menu item is part of a nest menu, the sequence is,
<code>JPopupMenu</code>, <code>JMenu</code>, <code>JPopupMenu</code>, and <code>JMenuItem</code>.
<pre> // Get the selected menu path
MenuElement[] path = MenuSelectionManager.defaultManager().getSelectedPath();
if (path.length == 0) {
// No menus are opened or menu items selected
}
// Retrieve the labels of all the menu elements in the path
for (int i=0; i<path.length; i++) {
Component c = path[i].getComponent();
if (c instanceof JMenuItem) {
JMenuItem mi = (JMenuItem)c;
String label = mi.getText();
// Note: JMenu is a subclass of JMenuItem; also JMenuBar does not have a label
}
}
</pre>
<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td bgcolor="#6666cc" align="center"><font color="#ffffff">
<b>Related Examples</b></font></td>
</tr>
</table>
e808. <a class="eglink" href="Menu.html?l=rel">
Creating a JMenuBar, JMenu, and JMenuItem Component
</a>
<br>
e809. <a class="eglink" href="MenuSep.html?l=rel">
Separating Menu Items in a Menu
</a>
<br>
e810. <a class="eglink" href="Popup.html?l=rel">
Creating a Popup Menu
</a>
<br>
e811. <a class="eglink" href="NestedPopups.html?l=rel">
Creating a Popup Menu with Nested Menus
</a>
<br>
e812. <a class="eglink" href="PopupHw.html?l=rel">
Forcing a Popup Menu to Be a Heavyweight Component
</a>
<br>
e814. <a class="eglink" href="MenuItemSelEvt.html?l=rel">
Creating a Menu Item That Listens for Changes to Its Selection Status
</a>
<br>
e815. <a class="eglink" href="PopupSelChg.html?l=rel">
Listening for Changes to the Currently Selected Menu or Menu Item
</a>
<br>
<table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td align="left">
<br>
See also:
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Actions">
Actions
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JButton">
JButton
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JCheckBox">
JCheckBox
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JComboBox">
JComboBox
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JDesktop%20and%20JInternalFrame">
JDesktop and JInternalFrame
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JFrame,%20JWindow,%20JDialog">
JFrame, JWindow, JDialog
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JLabel">
JLabel
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JList">
JList
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JProgressBar">
JProgressBar
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JRadioButton">
JRadioButton
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JScrollPane">
JScrollPane
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JSlider">
JSlider
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JSpinner">
JSpinner
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JSplitPane">
JSplitPane
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JTabbedPane">
JTabbedPane
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#JToolBar">
JToolBar
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Keystrokes%20and%20Input%20Maps">
Keystrokes and Input Maps
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Layout">
Layout
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Look%20and%20Feel">
Look and Feel
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Progress%20Monitor">
Progress Monitor
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#The%20Screen">
The Screen
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#Tool%20Tips">
Tool Tips
</a>
<a class="eglink" href="/egs/javax.swing/pkg.html?l=rel#UI%20Default%20Values">
UI Default Values
</a>
</td>
</tr>
</table>
<br>
<br>
<FONT class="xsmall-font">
© 2002 Addison-Wesley.
</FONT></TD><TD> </TD><TD valign="top"><A href="http://compositesw.com/devzone?ref=javaalmanac"><IMG alt="Click Here" height="600" width="120" border="0" src="/csw_oad_120x600_final.gif"></A></TD>
</TR>
</TABLE>
</BODY>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<META CONTENT="NO-CACHE" HTTP-EQUIV="PRAGMA">
</HEAD>
</HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -