MACROMEDIA FLEX, Справочник

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this 213
this
Availability
Flash Player 5.
Usage
this
Description
Identifier; refers to the object in the currently executing scope. If you are in a method and you
want a reference to the object instance, use the
this
identifier. You can also use the
this
identifier to pass a class instance as an argument of a method to itself or another class.
Because
this
is evaluated in the context of the script that contains it, you can’t use
this
in a
script to refer to a variable defined in a class file. Create ApplyThis.as, and enter the following
code:
class ApplyThis {
var str:String = "Defined in ApplyThis.as";
function conctStr(x:String):String {
return x+x;
}
function addStr():String {
return str;
}
}
Then, in a FLA or AS file, add the following ActionScript:
var obj:ApplyThis = new ApplyThis();
var abj:ApplyThis = new ApplyThis();
abj.str = "defined in FLA or AS";
trace(obj.addStr.call(abj, null)); //output: defined in FLA or AS
trace(obj.addStr.call(this, null)); //output: undefined
trace(obj.addStr.call(obj, null)); //output: Defined in applyThis.as
Similarly, to call a function defined in a dynamic class, you must use
this
to invoke the function
in the proper scope:
// incorrect version of Simple.as
/*
dynamic class Simple {
function callfunc() {
trace(func());
}
}
*/
// correct version of Simple.as
dynamic class simple {
function callfunc() {
trace(this.func());
}
}
CHAPTER 5
ActionScript Core Language Elements