XML作为Actionscript / Flex中的XMLNode

Question

How do I get the root node of an XML object in Actionscript?

One would think that I could say this:

var Node:XMLNode = XMLVar as XMLNode;

But although XMLVar is of type XML, Node will = null.

So how do I do it?

Answer 1

You code is a little confusing because you are using uppercase first characters for you variable names. Take a look at Adobe's coding conventions for AS3 .

var xmlData:XML = new XML();
var node:XMLNode = xmlData.firstChild();

This example is pretty useless, but it just demonstrate the method.

Use the XML object's firstChild method . To get the first node as a XMLNode object.

Answer 2

var node:XMLNode = xmlVar as XMLNode;

although xmlVar is of type XML

XML and XMLNode are not compatible in ActionScript-3. XML class of AS2 (and its related classes) has been renamed to flash.xml.XMLDocument in AS3.

The XMLNode / XMLDocument class represents the legacy XML object that was present in ActionScript 2.0 and that was renamed in ActionScript 3.0. In ActionScript 3.0, consider using the new top-level XML class and related classes instead, which support E4X (ECMAScript for XML). The XMLNode / XMLDocument class is present for backward compatibility.

An object of type XML cannot be cast directly to XMLNode . Since you're trying to cast with as keyword, it just returns null instead of raising an alarm saying the cast failed.

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And as already mentioned, consider using lowerCase names for variables, as UpperCase names are normally used for naming classes.