AS3 CookBook学习整理(十六)
1. 读取XML元素的属性
假设有下面的xml：
var xml:XML = <menu> <item title="蜀绣" author="李宇春">栏目A</item> <item title="青花瓷" author="周杰伦">栏目B</item> <distinctItem><subItem>特别栏目</subItem></distinctItem> <item title="蓝莲花" author="许巍">栏目C</item> </menu>;
得到某个节点的某个属性
xml.item[1].@author
得到某个节点的所有属性，调用name( ) 方法可显示出属性名
var attrList:XMLList = xml.item[1].attributes();
for each(var node:XML in attrList)
{
trace(node.name() + "：" + node);
}调用attribute("attrName")来得到所有名称为"attrName"的属性
var attrList:XMLList = xml.item.attribute("title");
for each(var node:XML in attrList)
{
trace(node);
}可以使用操作符 * 和 @ 来得到所有属性
var list:XMLList = xml..@*; //如果有特殊字符，需要这样访问：xml..@["music-title"]
for each(var attr:XML in list)
{
trace(attr.name() + ":" + attr);
}2. 删除XML元素，文本节点和属性
使用delete关键字
package {
import flash.display.Sprite;
public class Sample0709 extends Sprite
{
public function Sample0709()
{
var xml:XML = <menu>
<item title="蜀绣" author="李宇春">栏目A</item>
<item title="青花瓷" author="周杰伦">栏目B</item>
<distinctItem><subItem>特别栏目</subItem></distinctItem>
<item title="蓝莲花" author="许巍">栏目C</item>
</menu>;
//删除文本节点
delete xml.item[1].text()[0];
//删除指定节点
delete xml.item[0];//删除子节点
delete xml.distinctItem.subItem;
//删除所有属性 delete xml.item.@*; trace(xml); } } }
3. 载入XML
使用URLLoader.load()方法并且设置dataFormat属性为DataFormat.TEXT读取数据，通过complete事件转换载入的数据为XML实例
PS：为避免非XML正常格式带来的转换错误，应该加入异常处理(捕获TypeError)
package {
import flash.display.Sprite;
import flash.events.Event;
import flash.net.URLLoader;
import flash.net.URLLoaderDataFormat;
import flash.net.URLRequest;
import flash.system.System;
public class Sample0710 extends Sprite
{
public function Sample0710()
{
flash.system.System.useCodePage = true;
var loader:URLLoader = new URLLoader(new URLRequest("http://www.xxx.com/test.xml"));
loader.dataFormat = URLLoaderDataFormat.TEXT;
loader.addEventListener(Event.COMPLETE,onComplete);
}
private function onComplete(event:Event):void
{
try
{
var xml:XML = new XML(event.target.data);
delete xml..channel[0];
trace(xml);
}
catch(e:TypeError)
{
trace("不是有效的XML格式文档，转换错误");
trace(e.message);
}
}
}
}4. 发送XML数据给服务端脚本
调用sendToURL()和navigateToURL()发送数据，注意设置URLRequest的如下属性：
request.data = xml; //一个xml对象
request.contentType = "text/xml";
request.method = URLRequestMethod.POST;
服务器端代码(.net)
protected void Page_Load(object sender, EventArgs e)
{
XmlDocument xml = new XmlDocument();
xml.Load(Request.InputStream);
//XmlNode node = xml.DocumentElement; //获取root
XmlNodeList nodeList = xml.SelectSingleNode("musicBox").ChildNodes;
for (int i = 0; i < nodeList.Count; i++)
{
Response.Write(nodeList.Item(i).Attributes[0].Value + "--" + nodeList.Item(i).InnerXml + "<br />");
}
}flex代码：
package {
import flash.display.Sprite;
import flash.events.MouseEvent;
import flash.net.URLRequest;
import flash.net.URLRequestMethod;
import flash.net.navigateToURL
public class Sample0710 extends Sprite
{
private var request:URLRequest;
public function Sample0710()
{
var xml:XML = <musicBox>
<song author="游鸿明">花沙</song>
<song author="陈奕迅">于心有愧</song>
<song author="许哲佩">日光恋人</song>
</musicBox>;
request = new URLRequest("http://localhost:5611/Default.aspx");
request.data = xml;
request.contentType = "text/xml";
request.method = URLRequestMethod.POST;
stage.addEventListener(MouseEvent.CLICK,onClick);
}
private function onClick(event:MouseEvent):void
{
navigateToURL(request);
}
}
}5. 搜索XML
假如有如下的XML：
var xml:XML = <foodGroup>
<fruits>
<fruit color="red">苹果</fruit>
<fruit color="yellow">香蕉</fruit>
<fruit color="green">西瓜</fruit>
<fruit color="yellow">鸭梨99</fruit>
</fruits>
<vegetables>
<vegetable color="red">西红柿</vegetable>
<vegetable color="brown">土豆</vegetable>
<vegetable color="purple">茄子</vegetable>
</vegetables>
</foodGroup>;直接通过点操作符定位
var singleNode:XML = xml.fruits.fruit[0]; //单个节点
var nodeList:XMLList = xml.fruits.fruit;//节点集合
for each(var node:XML in nodeList)
{
trace(node);
}通过双点操作符得到未知路径下的节点
var nodeList:XMLList = xml..vegetable;
for each(var node:XML in nodeList)
{
trace(node);
}通过 * 操作符得到任意节点
var nodeList:XMLList = xml.*.fruit;
for each(var node:XML in nodeList)
{
trace(node);
}@ 符号用来访问属性
var nodeList:XMLList = xml.fruits.fruit.@color;
for each(var node:XML in nodeList)
{
trace(node);
}调用hasOwnProperty("attributeName")检查是否有某属性
var nodeList:XMLList = xml..fruit.(!hasOwnProperty("@color"));
for each(var node:XML in nodeList)
{
trace(node);
}检查节点的属性值
var nodeList:XMLList = xml..fruit.(@color=="yellow");
for each(var node:XML in nodeList)
{
trace(node);
}检查节点值，并应用正则表达式
var nodeList:XMLList = xml.fruits.fruit;
for each(var node:XML in nodeList)
{
if(node=="西瓜")
{
trace(node.@color);
}
if(/\d/.test(node))
{
trace(node);
}
}6. 在XML中使用HTML和特殊字符
使用CDATA标签，以 <![CDATA[ 开始，以 ]]> 结束
package {
import flash.display.Sprite;
import flash.net.URLRequest;
public class Sample0710 extends Sprite
{
private var request:URLRequest;
public function Sample0710()
{
var xml:XML = <menu>
<item><![CDATA[a>b]]></item>
<item><![CDATA[<a href="#">链接</a>]]></item>
</menu>;
for each(var node:XML in xml.elements())
{
trace(node);
}
}
}
}7. 在Flex里调用WebServices
Flash播放器没有内建web services支持，也不理解SOAP；不过Flash播放器能在HTTP上通讯，能解析XML数据，实际上SOAP web services也是在HTTP上通讯且SOAP协议也是以XML为基础的协议，因此用ActionScript完全可以调用web services方法，Flex framework 提供了解决方案
WebServices代码：(.net)
[WebMethod]
public string HelloWorld()
{
return "Hello World";
}
[WebMethod]
public string GetUser(string name, int age)
{
return name + " is " + age + " years old";
}Flex代码：
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<mx:WebService id="ws1" wsdl="http://localhost:4223/WebService1.asmx?WSDL">
<mx:operation name="HelloWorld" result="onResult(event);" fault="onFault(event);">
</mx:operation>
<mx:operation name="GetUser" result="onResult(event);" fault="onFault(event);">
<mx:request>
<name>臣本布衣</name>
<age>26</age>
</mx:request>
</mx:operation>
</mx:WebService>
<mx:Text id="txtValue" x="300" y="50"></mx:Text>
<mx:Button label="调用HelloWorld" click="ws1.HelloWorld.send();" x="300" y="100"></mx:Button>
<mx:Button label="调用GetUser" click="ws1.GetUser.send();" x="300" y="200"></mx:Button>
<mx:Script>
<![CDATA[
import mx.rpc.events.FaultEvent;
import mx.rpc.events.ResultEvent;
private function onResult(event:ResultEvent):void
{
this.txtValue.text = event.result.toString();
}
private function onFault(event:FaultEvent):void
{
this.txtValue.text = event.fault.toString();
}
]]>
</mx:Script>
</mx:Application>8. AS调用Javascript函数
如果是比较简单的调用(例如alert('abc');)，可以直接利用navigateToURL，这也是兼容所有浏览器的做法：
navigateToURL(new URLRequest("javascript:alert('老胡');"), "_self");
navigateToURL(new URLRequest("javascript:myFunc('老胡',27);"), "_self");
一般情况下应该使用ExternalInterface.call(funcName, parameters);
Javascript代码：
<script type="text/javascript">
function saySomething(name, age)
{
alert(name + " is " + age + " years old");
}
function getSomething()
{
return "贾君鹏你妈妈喊你回家吃饭";
}
</script>AS3代码：
package {
import flash.display.Sprite;
import flash.events.MouseEvent;
import flash.external.ExternalInterface;
import flash.net.URLRequest;
import flash.net.navigateToURL;
import flash.text.TextField;
public class Sample0721 extends Sprite
{
private var textBox:TextField;
public function Sample0721()
{
var button:Sprite = new Sprite();
button.graphics.beginFill(0xFF0000);
button.graphics.drawRect(100,100,100,50);
button.graphics.endFill();
button.addEventListener(MouseEvent.CLICK,button_Click)
this.addChild(button);
textBox = new TextField();
textBox.text = "点击获取返回值";
textBox.x = textBox.y = 200;
textBox.addEventListener(MouseEvent.CLICK,textBox_Click);
this.addChild(textBox);
}
private function button_Click(event:MouseEvent):void
{
ExternalInterface.call("saySomething","胡晓伟",26);
}
private function textBox_Click(event:MouseEvent):void
{
textBox.text = ExternalInterface.call("getSomething");
}
}
}PS:要注意在HTML代码里嵌入swf文件的方式，之前仅仅用了Embed嵌入，导致了IE无法获得Javascript函数的返回值
9. Javascript调用AS函数
使用ExternalInterface.addCallback(jsFuncName, asFuncName)
在客户端需要得到Flash播放器的对象引用，浏览器中的Flash播放器有两种类型：ActiveX和plug-in版本，ActiveX版本运行在Internet Explorer上，而plug-in版本运行在其它浏览器上
ActiveX版本播放器由HTML页中的
一般情况下，我们并不知道用户使用什么版本的Flash播放器，有个方法是通过JavaScript的navigator.appName来检测用户浏览器的类型：
如果navigator.appName 包含Microsoft关键字，那么用户使用的就是Internet Explorer，也就是ActiveX 播放器
如果navigator.appName 不包含Microsoft关键字，也就意味着是plug-in 版本播放器
AS代码：
package {
import flash.display.Sprite;
import flash.external.ExternalInterface;
public class Sample0721 extends Sprite
{
public function Sample0721()
{
ExternalInterface.addCallback("drawCircle",addRectToStage);
}
private function addRectToStage():String
{
var circle:Sprite = new Sprite();
circle.graphics.beginFill(0xFFFF00);
circle.graphics.drawCircle(Math.random()*300,Math.random()*300,20);
circle.graphics.endFill();
this.addChild(circle);
return "战斗大师的勇气";
}
}
}Javascript代码：
<script type="text/javascript">
function callAS()
{
var flashPlayer;
if (navigator.appName.indexOf("Microsoft") != -1)
{
flashPlayer = document.getElementById("hxwSwf");
}
else
{
flashPlayer = document["hxwSwf"];
}
alert(flashPlayer.drawCircle());
}
</script>10. 从HTML传递参数给Flash
使用FlashVars以"key1=value1&key2=value2"的形式传递参数（如果有特殊符号，例如&，需要用URL编码为%26)，Flash端通过root.loaderInfo.parameters得到该FlashVars数组的引用
HTML代码：
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"> <param name="FlashVars" value="userName=关云%26长&group=蜀国"> <embed type="application/x-shockwave-flash" FlashVars="userName=张文远&group=魏国"> </object>
AS3代码：
package {
import flash.display.Sprite;
import flash.text.TextField;
public class Sample0721 extends Sprite
{
public function Sample0721()
{
var label:TextField = new TextField();
this.addChild(label);
var obj:Object = root.loaderInfo.parameters;
label.text = obj.userName;
}
}
}
