Tuesday 8 April 2008

Sound in Flash CS3


In flash, sometimes you might want to add a sound using actionscript, for example:- background music that repeats for ever, or a sound that plays only when you shoot a gun. I'm going to show you how to make this happen!


1st, find a sound or some music that you have in your computer, when you have found one remember its file path.
Next open up flash cs3 and click File:Import:Import to Library. and then choose your sounds file path from the menu that pops up. 



Then, press control + L to open the library and something like this should appear. 

Obviously the sound name will be different, but it will look mostly the same as this.

Next right click on the sound name (highlighted) and choose linkage from the menu that appears.





A box should pop up that looks something like this, but without the "Export for ActionScript" checkbox ticked. 
Check this and then write a class name in the box that is highlighted on the screenshot. But you have to remember this, as we will be using it a bit later. I have called mine "acoust", so if you have problems with the script i suggest you use that name.


Now we are ready to make the sound play.

just 3 lines of actionscript are required to make the sound play.

import flash.media.Sound;
var sound:Sound = new acoust();
sound.play(0, 99);

I am not going to make a demo, as it will be quite CPU intensive and also it will interfere with the later experiments.

Line 1: importing the necessary classes for the sound to play.
Line 2: Setting up a new variable "sound", which is a copy of the class "acoust" that we set up earlier.
Line 3: Setting the variable "sound" to play 99 times starting at 0 miliseconds.

Now lets make some buttons that can stop and play the sound.





This script is a lot more complicated than the 1st script that i showed you this is because i have had  to play and stop the sound on command. For this i had to add 2 more variables, one to see if the sound was playing and another one that is a soundchannel variable. some code:-


import flash.media.Sound;
var sound:Sound = new acoust();
var channel:SoundChannel;
var soundisplaying:Boolean = false;
playbut.addEventListener(MouseEvent.CLICK, playsound);
stopbut.addEventListener(MouseEvent.CLICK, stopsound);
function playsound(event:Event):void {
if (soundisplaying==false) {
channel = sound.play(0, 99);
soundisplaying = true;
}
}
function stopsound(event:Event):void {
channel.stop();
soundisplaying =false;
}



The first thing that you will notice is the new soundChannel variable "channel". This sets up a new channel which i will use to hold the sound.play() function.

Next, you will notice the "soundisplaying" boolean variable, this quite literally tells us if the sound is playing. I set this up to stop multiple versions of the sound playing when you pressed the play button. it is set to false to start with.

The next 2 lines are adding the event listeners for when the buttons are pressed. i have explained buttons in more detail in this tutorial.

You can see that i have added 2 new functions for controlling the sound. 

The first one plays the sound, but only is the boolean soundisplaying is set to false, that is what the if statement is for. The channel = sound.play is the same function as before, then i set the soundisplaying variable to true, so the user can't play the sound more than once.

The next function is the one that stops the sound playing. You cannot directly stop the sound, so you have to stop the soundChannel that it is attached to, so the code is channel.stop().
I also set the soundisplaying boolean to false, so that if you click the play button you can restart the sound.

thats it so far, next time i will be focusing on pausing and then replaying the sound from the pause point.

3 comments:

UnionJackson said...

phwoar! great stuff :D
thanks for the help, you got some ace guides here! :D

Anonymous said...

Thank you! It's awesome of you to share the code. May you have good things come to you in return of your generosity ; )

Anonymous said...

thank you very much!
I see that sound.stop() doesn't work anymore