在另一个框架上的AS3导入类

Question

I am using external AS files for a new project of mine, which involved creating a place to draw so i used the following tutorial to get a basic idea of what is need.

I got the hope application working and running smoothly until i decided i wanted to add in a preloading & Menu - putting the drawing part of the app on the third frame - which got me this error:

TypeError: Error #1009: Cannot access a property or method of a null object reference.
- at Main/convertToBMD()
- at Main()

So I thought instead of adding the Main.as to the Class under properties i would import the file on the frame instead. Using:

var main:Main = new Main();
addChild(main);

This worked apart from it loses all connections to the instance names.

Line 64 1120: Access of undefined property pencil.
Line 65 1120: Access of undefined property eraser.
Line 65 1120: Access of undefined property txt.
Line 82 1120: Access of undefined property board.
Line 83 1120: Access of undefined property board.

Etc.....

So what i would like to know, is there a better way of doing this and getting it working on any frame?

By changing something in the external script or another way of importing onto frame?

Thank you

Eli

Answer 1

The problem is that named instances are properties of the MainTimeline instance, which is typically the first child of the stage. The properties are not properties of your Main class (anymore).

So, when you want to access these properties from with Main , you could do something like:

var timeline:DisplayObject = stage.getChildAt(0);
var pencil:DisplayObject = timeline["pencil"];

// do stuff with 'pencil'
pencil.x = 500;
...

Note: This assumes Main will have its stage property set, which should be the case once you've added it through addChild(main); . But this means that, in the constructor of Main , you won't be able to access the stage property yet to do the above. If this is a problem, considering having Main wait for the ADDED_TO_STAGE event before using 'pencil', etc.