flex的Canvas可以和HTML的DIV一样做块状的网格布局
用到的MX标签：constraintColumns、ConstraintColumn、constraintRows、ConstraintRow
给大家说说前提情况：在做MXML布局时，要嵌套很多层级，这里面有很多问题：
1、嵌套太多层级会影响效率！
2、嵌套太多层级，代码的可读性、可维护性差！
3、嵌套太多层级是因为Canvas、Vbox、Hbox功能单一，不能满足需要，而不是必须要这样做。
好吧，来看一个MXML代码示例：
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" minWidth="955" minHeight="600">
<mx:constraintColumns>
<mx:ConstraintColumn id="column1" width="250"/>
<mx:ConstraintColumn id="column2" width="100%"/>
</mx:constraintColumns>
<mx:constraintRows>
<mx:ConstraintRow id="row1" height="25"/>
<mx:ConstraintRow id="row2" height="25"/>
<mx:ConstraintRow id="row3" height="100%"/>
<mx:ConstraintRow id="row4" height="35"/>
</mx:constraintRows>
<mx:Button id="topMenuCvs" label="topMenuCvs" width="100%"
top="row1:0" bottom="row1:0"/>
<mx:Button id="topButtonCvs" label="topButtonCvs" width="100%"
top="row2:0" bottom="row2:0"/>
<mx:Button id="leftNavCvs" label="leftNavCvs" height="100%"
top="row3:0" bottom="row3:0" left="column1:0" right="column1:0"/>
<mx:Button id="leftMainCvs" label="leftMainCvs" height="100%"
top="row3:0" bottom="row3:0" left="column2:0" right="column2:0"/>
<mx:Button id="footCvs" label="footCvs" width="100%"
top="row4:0" bottom="row4:0"/>
</mx:Application>
效果图：
相关文档：
/*Copyright (c) 2006 Adobe Systems Incorporated
Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, m ......
2.2 代码实现
下面给出了FlexBuilder工程的一个文件，设置了Flash的布局。
view plaincopy to clipboardprint?
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
......
servlet 端：
String userId = request.getParameter("userId");
System.out.println(userId);
response.setCharacterEncoding("UTF-8");
response.getWriter().println("hello world -- 我爱你。。。");
Flex 前台端
<fx:Script>
<![CDATA[
import flash.trace.Trace;
private var loader:UR ......
很多时候，我们需要将下拉框里面的数据用树显示出来，这样会便于客户得到清晰的数据，而且比较直接，晾出以下HTML代码，可以直接复制到HTML代码里面运行！
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-tran ......
string str = a.ToString();
str = Regex.Replace(str, @"</?span[^>]*>", "", RegexOptions.IgnoreCase);
str = Regex.Replace(str, @"&#[^>]*;", "", RegexOptions.IgnoreCase);
str = Regex.Replace(str, @"</?marquee[^>]*>", "", RegexOptions.IgnoreCase);
str = Regex.Replace(str, ......
