从Flash 8到CS3

Question

After many years of using Flash 8, I'm moving to CS3 at work. I know I'll have to learn AS 3.0 so, does anyone have any good references or summaries of the major/most noticeable changes? Also, are there any tips/tricks for the flash environment? After spending a few minutes in CS3, I noticed that you can't directly attach actionscript to a button, which is new to me. Any other such pitfalls to watch over?

Answer 1

I made the total switch just about 3 months ago, here are some things that helped me ramp up rather quickly:

1) Do everything in Class files

A lot of AS3 tutorials out there deal with just code pasted on the timeline (which I can't stand because now you have to hunt for what import you need) , but is fine for quick tiny stuff. In the long run it's way better work primarily in Class files. Learning how Classes work opened a huge door for me, it was the same feeling/experience I had when I first discovered Functions in AS2 :)

2) Keep graphics in library and off the workspace

Example, you have a jpg, gif, png file you just imported into your library. Made a movieClip and gave it a class name( MyButton ). Now the code below will place the graphic into the workspace for you:

var myButton:MovieClip = new MyButton();
    myButton.x = 6;
    myButton.y = 22;
    myButton.buttonMode = true;

addChild(myButton);    

3) Get use to the new button code in AS3

It's something all of us new converts had to deal with painfully, but now it's a piece of cake :)

myButton.addEventListener(MouseEvent.MOUSE_UP, clickThis);

function clickThis(event:MouseEvent):void
        {
            navigateToURL(new URLRequest("form.html"), "_self");
            //navigateToURL(request, '_self');
        }

4) Make sure you remove Event Listeners after use

It took me a bit to wrap my around this one... remove em why? Oh they are still running in the background and when I listen again I'll get all kinds of mutated errors.

private function volDown(e:MouseEvent):void
    {
        masker.width = volControl.mouseX;
        userVolume = (masker.width / 100) * 1;
        volControl.addEventListener(MouseEvent.MOUSE_MOVE, volMove);
    }

private function volUp(e:MouseEvent):void
    {
        lastVolPoint = masker.width;
        setVolume(userVolume);
        e.updateAfterEvent();
        volControl.removeEventListener(MouseEvent.MOUSE_MOVE, volMove);
    }

5) Don't forget to pass Events

I'm not a programmer by trade and this has caused so much grief, I'm glad I'm done with this birthing pain:

myButton.addEventListener(MouseEvent.MOUSE_UP, clickThis);

Since the clickThis function is launched via an Event, you have to pass: event:MouseEvent into it like so:

function clickThis(event:MouseEvent):void

Because the code below will throw the dreaded AS3 "Access of undefined property" error that new AS3 guys will always run into.

function clickThis():void

6) Read and post questions on StackOverflow... a lot!

btw I'm still a noob and originally a designer then AS2 dev, I still don't know why we put :void behind a function name.. if we have similar coding backgrounds I hope all that helps :)

Answer 2

I suggest you to look at the ActionScript language migration page on the Adobe devnet. It offers quite a lot articles about the key changes with ActionScript 3.

To answer your problem with the actions on a button, this no longer works (and was already with ActionScript 2 not the best way to do it). AS3 requires the code to be centralized on the timeline. So for giving a button some action, you'll need to give it an instance name and add an event listener for the CLICK event, like this:

function doSomething ( event:MouseEvent ):void
{
    trace( "test" );
}
myButton.addEventListener( MouseEvent.CLICK, doSomething );

Answer 3

Get an Actionscript 3 IDE. Such as Flash Builder, FlashDevlop, or FDT. This will force you to learn really fast.