Referring to Instances and Main Movies
earlier sections, we learned how to create
and layer movie clip instances and external
files in the Flash Player. We must be able to refer to that content
in order to effectively control it with ActionScript.
We refer to instances and main movies under four general circumstances, when we want to:
Get or set a property of a clip or a movie
Create or invoke a method of a clip or a movie
Apply some function to a clip or a movie
Manipulate a clip or a movie as data, for example, by storing it in a variable or passing it as an argument to a function
While the circumstances under which we refer to clip instances and movies are fairly simple, the tools we have for making references are many and varied. We’ll spend the rest of this section exploring ActionScript’s instance- and movie-referencing tools.
Using Instance Names
Earlier, we learned that movie clips are referred to by their instance names. For example:
trace(myVariable); // Refer to a variable trace(myClip); // Refer to a movie clip
In order to refer to an instance directly (as shown in the preceding
trace( ) example), the instance must reside on
the timeline to which our code is attached. For example, if we have
an instance named
clouds placed on the main
timeline of a document, we may refer to
from code attached to the main timeline as follows:
// Set a property of the instance clouds._alpha = 60; // Invoke a method on the instance clouds.play( ); // Place the instance in an array ...