本文实例讲述了java swing中jlist选择事件监听器listselectionlistener用法。分享给大家供大家参考，具体如下：
当jlist中的元素被选中时，选择事件将被触发。对于jtable也是一样，你可以把它看做是多个并列的jlist。那么，如果程序需要对该事件做出响应，需要以下步骤：
(1)创建一个实现了 listselectionlistener的监听器；
(2)使用jlist或selectionmodel的addlistselectionlistener添加监听器；
(3)在监听器的valuechanged方法添加响应代码。
在响应代码中需要注意的是getvalueisadjusting值的判断。测试表明，每当我们进行选择时，valuechanged方法都会被激活多次，其中，在最后的鼠标操作中，getvalueisadjusting值为false，而在一系列中间操作中，该值均为true。比如说，用鼠标连续划过一串元素时，会有一系列getvalueisadjusting为true的valuechanged方法激活，且最后一次为false。而我们对选择事件的判定一般是以最后接触为准，因此这里对getvalueisadjusting值进行一个判断。
常用方法如下：
getleadselectionindex()
返回当前选中的元素的index。
getminselectionindex()
返回选中的多个元素中index的最小值，如果选择为空在返回-1。
getmaxselectionindex()
原理同上。
isselectedindex(int index)
判断指定index是否被选中。
clearselection()
清除选中。
getselectedindex()
返回被选中的所有元素中最小的index。
getselectedindices()
返回一个整型数组，包含被选中的所有index。
getselectedvalue()
返回被选中的，index最小的元素值。
getselectedvalues()
返回一个object数组，包含被选中的所有元素对象。
getselectedvalueslist()
返回一个objectlist，包含被选中的所有元素对象。
下面的demo来自于listselectiondemo.java
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/* * copyright (c) 1995, 2008, oracle and/or its affiliates. all rights reserved. * * redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - neither the name of oracle or the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * this software is provided by the copyright holders and contributors "as * is" and any express or implied warranties, including, but not limited to, * the implied warranties of merchantability and fitness for a particular * purpose are disclaimed. in no event shall the copyright owner or * contributors be liable for any direct, indirect, incidental, special, * exemplary, or consequential damages (including, but not limited to, * procurement of substitute goods or services; loss of use, data, or * profits; or business interruption) however caused and on any theory of * liability, whether in contract, strict liability, or tort (including * negligence or otherwise) arising in any way out of the use of this * software, even if advised of the possibility of such damage. */ package awtdemo;/* * listselectiondemo.java requires no other files. */import javax.swing.*;import javax.swing.event.*;import java.awt.*;import java.awt.event.*;@suppresswarnings("serial")public class listselectiondemo extends jpanel { jtextarea output; @suppresswarnings("rawtypes") jlist list; jtable table; string newline = "\n"; listselectionmodel listselectionmodel; @suppresswarnings({ "unchecked", "rawtypes" }) public listselectiondemo() { super(new borderlayout()); string[] listdata = { "one", "two", "three", "four", "five", "six", "seven" }; @suppresswarnings("unused") string[] columnnames = { "french", "spanish", "italian" }; list = new jlist(listdata); listselectionmodel = list.getselectionmodel(); listselectionmodel.addlistselectionlistener( new sharedlistselectionhandler()); jscrollpane listpane = new jscrollpane(list); jpanel controlpane = new jpanel(); string[] modes = { "single_selection", "single_interval_selection", "multiple_interval_selection" }; final jcombobox combobox = new jcombobox(modes); combobox.setselectedindex(2); combobox.addactionlistener(new actionlistener() { public void actionperformed(actionevent e) { string newmode = (string)combobox.getselecteditem(); if (newmode.equals("single_selection")) { listselectionmodel.setselectionmode( listselectionmodel.single_selection); } else if (newmode.equals("single_interval_selection")) { listselectionmodel.setselectionmode( listselectionmodel.single_interval_selection); } else { listselectionmodel.setselectionmode( listselectionmodel.multiple_interval_selection); } output.append("----------" + "mode: " + newmode + "----------" + newline); } }); controlpane.add(new jlabel("selection mode:")); controlpane.add(combobox); //build output area. output = new jtextarea(1, 10); output.seteditable(false); jscrollpane outputpane = new jscrollpane(output, scrollpaneconstants.vertical_scrollbar_always, scrollpaneconstants.horizontal_scrollbar_as_needed); //do the layout. jsplitpane splitpane = new jsplitpane(jsplitpane.vertical_split); add(splitpane, borderlayout.center); jpanel tophalf = new jpanel(); tophalf.setlayout(new boxlayout(tophalf, boxlayout.line_axis)); jpanel listcontainer = new jpanel(new gridlayout(1,1)); listcontainer.setborder(borderfactory.createtitledborder( "list")); listcontainer.add(listpane); tophalf.setborder(borderfactory.createemptyborder(5,5,0,5)); tophalf.add(listcontainer); //tophalf.add(tablecontainer); tophalf.setminimumsize(new dimension(100, 50)); tophalf.setpreferredsize(new dimension(100, 110)); splitpane.add(tophalf); jpanel bottomhalf = new jpanel(new borderlayout()); bottomhalf.add(controlpane, borderlayout.page_start); bottomhalf.add(outputpane, borderlayout.center); //xxx: next line needed if bottomhalf is a scroll pane: //bottomhalf.setminimumsize(new dimension(400, 50)); bottomhalf.setpreferredsize(new dimension(450, 135)); splitpane.add(bottomhalf); } /** * create the gui and show it. for thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createandshowgui() { //create and set up the window. jframe frame = new jframe("listselectiondemo - www.zzvips.com"); frame.setdefaultcloseoperation(jframe.exit_on_close); //create and set up the content pane. listselectiondemo demo = new listselectiondemo(); demo.setopaque(true); frame.setcontentpane(demo); //display the window. frame.pack(); frame.setvisible(true); } public static void main(string[] args) { //schedule a job for the event-dispatching thread: //creating and showing this application's gui. javax.swing.swingutilities.invokelater(new runnable() { public void run() { createandshowgui(); } }); } class sharedlistselectionhandler implements listselectionlistener { public void valuechanged(listselectionevent e) { listselectionmodel lsm = (listselectionmodel)e.getsource(); //system.out.printf("leadselectionindex is %s%n",lsm.getleadselectionindex()); output.append("leadselectionindex is " + lsm.getleadselectionindex() + "\n"); int firstindex = e.getfirstindex(); int lastindex = e.getlastindex(); boolean isadjusting = e.getvalueisadjusting(); output.append("event for indexes " + firstindex + " - " + lastindex + "; isadjusting is " + isadjusting + "; selected indexes:"); if (lsm.isselectionempty()) { output.append(" <none>"); } else { // find out which indexes are selected. int minindex = lsm.getminselectionindex(); int maxindex = lsm.getmaxselectionindex(); for (int i = minindex; i <= maxindex; i++) { if (lsm.isselectedindex(i)) { output.append(" " + i); } } } output.append(newline); output.setcaretposition(output.getdocument().getlength()); } }} |
运行效果：
希望本文所述对大家java程序设计有所帮助。
原文链接：http://www.cnblogs.com/pzy4447/p/4912584.html
