本文来自http://blog.csdn.net/hellogv/ ，引用必须注明出处！

      最近越来越多人用LWUIT，问得问题也越来越多了。最近超级多人问的是，如何使用List实现表格。以前我用Grid实现了表格(http://blog.csdn.net/hellogv/archive/2009/01/12/3759984.aspx),现在就来说说如何使用List是一个表格。

      先来对比一下Grid表格与List表格：

Grid表格                                List表格

Grid表格与List表格所消耗的资源差不多，List所使用的结构和控件(都是Label)略多，但是Grid使用的是Button(衍生于Label,但是多很多方法和属性)，所以两者的运行速度都差不多，至于用哪个，就看你喜欢了。

本文的源代码可以到这里下载：http://download.csdn.net/source/1792549

本文关键的两个文件是：Cls_CellList.java和ListDemo.java,Cls_CellList.java封装了本文所用的List,而ListDemo.java则是演示使用，代码简单易明，一般人也能看懂，呵呵呵。

Cls_CellList.java主要使用了ListCellRenderer这个东西，源代码如下：

package com.sun.lwuit.uidemo;import com.sun.lwuit.Component;import com.sun.lwuit.Container;import com.sun.lwuit.Label;import com.sun.lwuit.List;import com.sun.lwuit.events.ActionListener;import com.sun.lwuit.layouts.BorderLayout;import com.sun.lwuit.layouts.BoxLayout;import com.sun.lwuit.list.ListCellRenderer;import com.sun.lwuit.plaf.Border;public class Cls_CellList {    static public List createList(CellList[] celllist,int stringWidth,ActionListener lAListner) {        List list = new List(celllist);        list.getStyle().setBgTransparency(0);        //开始显示List        list.setListCellRenderer(new CellRenderer(celllist[0].getColumm().length,stringWidth));        //添加消息处理        list.addActionListener(lAListner);        return list;    } static public class CellRenderer extends Container implements ListCellRenderer {        //初始化显示Columm每个字段的Label        private Label[] lbColumm ;        private Label focus = new Label("");        public CellRenderer(int size,final int stringWidth) {            lbColumm = new Label[size];            setLayout(new BorderLayout());            Container cnt = new Container(new BoxLayout(BoxLayout.X_AXIS));            for(int i=0;i<lbColumm.length;i++)//定义显示Columm每个字段的Label            {                lbColumm[i]=new Label(){                    //很多人都问怎么setWidth平时没什么用，这是因为setWidth必须在重载的时候使用，LWUIT奇怪的地方之一！                    public void setWidth(int arg0) {                        super.setWidth(stringWidth);                    }                };                lbColumm[i].getStyle().setFgColor(getStyle().getFgSelectionColor());//设置为最亮的颜色                lbColumm[i].getStyle().setBgTransparency(0);//设置背景为透明，不然会遮挡focus影响外观                cnt.addComponent(lbColumm[i]);            }                        addComponent(BorderLayout.CENTER, cnt);            focus.getStyle().setBgTransparency(255);            focus.getStyle().setBorder(Border.createRoundBorder(10, 10));        }        public Component getListCellRendererComponent(List list, Object value, int index, boolean isSelected) {            CellList cellList = (CellList) value;            for(int i=0;i<lbColumm.length;i++)            {                lbColumm[i].setText(cellList.getColumm()[i]);            }            return this;        }        public Component getListFocusComponent(List list) {            //Columm栏不具备选中事件            if(list.getSelectedIndex()>0)                return focus;            return null;        }    }    static public class CellList {        //保存该列的所有字段        private String[] lstColumm;        public CellList(String[] columm) {           //复制数组           lstColumm=new String[columm.length];           System.arraycopy(columm, 0, lstColumm, 0, lstColumm.length);        }        //返回该列        public String[] getColumm(){           return lstColumm;        }    }}

ListDemo.java源代码如下：

/* * Copyright ?2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. * */package com.sun.lwuit.uidemo;import com.sun.lwuit.Command;import com.sun.lwuit.Font;import com.sun.lwuit.Form;import com.sun.lwuit.List;import com.sun.lwuit.events.ActionEvent;import com.sun.lwuit.events.ActionListener;import com.sun.lwuit.layouts.BorderLayout;public class ListDemo implements ActionListener  {    public Form form = new Form("ListDemo");    private  Command backCommand = new Command("Back", 1);    private String[][] myList = {        {"  标题1  ","  标题2  ","  标题3  "," 标题4 "},//表格每个字段的显示长度由标题栏的最长一项决定        {"aaaaa","bbbbb","ccccc","ddddd"},        {"11111","222222","33333","444444"},        {"aaaaa","bbbbb","ccccc","ddddd"},        {"11111","222222","33333","444444"},        {"aaaaa","bbbbb","ccccc","ddddd"},        {"11111","222222","33333","444444"},        {"aaaaa","bbbbb","ccccc","ddddd"},        {"11111","222222","33333","444444"}    };    ListDemo(){        form.setLayout(new BorderLayout());        form.addCommand(backCommand);        form.setScrollable(true);        //定义列表的列数        Cls_CellList.CellList[] cellArray = new Cls_CellList.CellList[myList.length];        for (int i = 0; i < cellArray.length; i++) {            cellArray[i] = new Cls_CellList.CellList(myList[i]);        }                //取得Columm的标题栏中长度最大的一项        int stringWidth=0;        for(int i=0;i<myList[0].length;i++)        {            int size=Font.getDefaultFont().stringWidth(myList[0][i])+8;//给最长的字段留点空余            if(stringWidth<size)                stringWidth=size;        }        //构造list并且显示        form.addComponent(BorderLayout.CENTER,Cls_CellList.createList(cellArray,stringWidth,new ListActionListener()));        form.setCommandListener(this);    }    public void actionPerformed(ActionEvent arg0) {          Command command=arg0.getCommand();        if(command==backCommand)            UIDemoMIDlet.backToMainMenu();    }    //按下列表触发的事件    private class ListActionListener implements ActionListener {        public void actionPerformed(ActionEvent evt) {            int selectIndex=((List)evt.getSource()).getSelectedIndex();            String str="";            for(int i=0;i<myList[selectIndex].length;i++)                str=str+myList[selectIndex][i]+"_";            form.setTitle(str);        }    }}