Actionscript 3.0: Scope

问题:

Tutorials usually don't deal with scope in Actionscript. Can you point me to some documentation and/or explain what should I know about it. I want to avoid problems arising from certain classes are not visible at certain places.

回答1:

These should help.

Function scope:

http://livedocs.adobe.com/flex/3/html/help.html?content=03_Language_and_Syntax_21.html

Packaging and namespace:

http://livedocs.adobe.com/flex/3/html/03_Language_and_Syntax_04.html#119303

回答2:

You're a bit vague, but hopefully I'm getting you ;)

Scope for classes are generally pretty easy to handle, it mostly comes down to packages. Packages are created in a simple tree structure, and in ActionScript3 the filestructre has to follow the namespaces. Which makes it even easier.

You can access any class from anywhere, but if it's in another package you will need to "import" the class. This is done by writing an import statement in the beginning of class or interface where you need to use it. Like so:

import flash.display.MovieClip;

There is an exception to this rule, a class can be declared with the internal keyword, in which case the class will only be available within that package. This is mostly used for helper classes.

Basicly you should not worry about classes not being available.

NB: You create package with the package keyword.