First of all I've just a couple hours experience with Flash and AS3 therefore, I'm sorry if it is a bit easy question.
What I want do to is a simple space war games to learn basics of AS3 and flash. Altough I dont know much things about layers, I think my game should contain two layers, one for background and the second one is for enemies spaceships and our spaceship.
I added a jpeg format file to library to use it as a background. (as you can see from the link :http://prntscr.com/2pe6zb and http://prntscr.com/2pe733 )
And I create a as3 documentFile which is called Arkaplan.as and content of it is:
package{
import flash .display.*;
public class Arkaplan extends MovieClip{
public function Arkaplan(){
var hero:backGround =new backGround();
addChild(hero);
}
}
}
However, I got an error which says that : "1180: Call to a possibly undefined method BackGround."
Is there anyone to help me to solve what is wrong ?
EDIT
When I changed the code above lilke :
package{
import flash .display.*;
public class Arkaplan extends MovieClip{
public function Arkaplan(){
var myBitmap:Bitmap = new Bitmap(new backGround(500, 500));
var myMovieclip:MovieClip=new MovieClip();
myMovieclip.addChild(myBitmap);
addChild(myMovieclip);
trace("deneme 1-2");
}
}
}
Problem is solved but I dont know why it runs correctly know ? To be able to use Bitmap Do I have to add it as a child to movieClip ?
Any time you use the word 'new' you are creating a new object. The word after new will be the name of a Class that Flash will try to locate. You must either have an external .as file that matches that name or have a library item set to 'export for ActionScript' with a Class name that matches that name.
You can access a library item's properties by right-clicking on it in the library and clicking 'properties'. With the 'advanced' option open, check the 'export for ActionScript' box and enter a Class name that matches the one you want to create.
Related
I recently picked up Emanuele Feronato's Flash Game Development by Example to try and help expand my knowledge of game design and actionscript 3, and I'm stuck on the first chapter where we're building basically a memory match two game where you have ten sets of tiles and you try and match them up by clicking on them.
In the code I'm stuck on, Mr. Feronato is adding the tiles to the stage using a for loop and addChild, here's the code in particular:
// tile placing loop
for (i:uint=0; i<NUMBER_OF_TILES; i++) {
tile = new tile_movieclip();
addChild(tile);
tile.cardType=tiles[i];
tile.x=5+(tile.width+5)*(i%TILES_PER_ROW);
tile.y=5+(tile.height+5)*(Math.floor(i/TILES_PER_ROW));
tile.gotoAndStop(NUMBER_OF_TILES/2+1);
tile.buttonMode = true;
tile.addEventListener(MouseEvent.CLICK,onTileClicked);
}
// end of tile placing loop
In the 5th line, you can see that he creates a custom property of the tile variable called "cardType," but when I try and run the code I get the error "Access of possibly undefined property cardType through a reference with static type Tile." I have the class Tile extending MovieClip, and the main class extends Sprite, but as far as I can tell I've written the code exactly as in the book and can't get past this. I thought about just using a normal int variable cardType to hold tiles[i] but later on you use the cardType property on a mouse event so I'm a little stuck.
Has something changed in Flash that no longer allows you to create custom properties in this way? Or did I just do something stupid that I'm not catching.
As always, thank you so much for the help.
ActionScript supports dynamic classes, in which properties may be added during runtime. Without the dynamic keyword, a class is sealed, meaning its properties may not be altered.
MovieClip is an example of a dynamic class.
Instantiating a MovieClip from code (or MovieClip instance created in Flash Professional), adding this property would be supported:
var tile:MovieClip = new MovieClip();
tile.cardType = "custom value";
However from code, even if extending MovieClip you must add the dynamic keyword:
package {
import flash.display.MovieClip;
public dynamic class Tile extends MovieClip {
/* ... */
}
}
Now, you may add properties to your Tile instance:
var tile:Tile = new Tile();
tile.cardType = "custom value";
So I had been messing around in AS3 for awhile and had done some basic starting flash game things, but then found out I could use air to make them for mobile platforms. So I tried copying over what I had worked on before, but I am running into issues.
Right now I am just trying to find out how to add an instance of a MovieClip to the stage. I have an image converted to a MovieClip with it's own class so I can manipulate it later (such as moving around) and I have this in my Main class:
class Main extends MovieClip
{
var space:Background; //Background is the MovieClip
function Main():void
{
space = new Background(stage);
stage.addChild(space);
}
}
But when I run the program, the image doesn't show up. It works that way when I just had a standard AS3 program and I don't understand why it would be different when I am trying to use AIR. Any assistance would be greatly appreciated, thank you.
Put the word 'public' in front of 'class' in your first line.
Also remove the 'stage' from the first line in your constructor: make it space = new Background();
And do you really need 'stage' in the addChild statement? Unnecessarily verbose!
I can run this code through the AIR compiler (AIR SDK 3.8 or later):
package
{
import flash.display.MovieClip;
public class MAIN extends MovieClip
{
var space:Background;
public function MAIN()
{
space = new Background();
stage.addChild(space);
}
}
}
With an image inside the Background class it shows up fine. My 'Background' is a library symbol linked for Actionscript. If your 'Background' is pure Actionscript are you adding a graphic to it?
Rajneesh Gaikwad had the answer, I didn't have my Main class as my Document class.
Just to preface: I haven't used Flash in a long long time, however, I am still aware of the environment.
Backstory: I created a small .fla to perform actions on a MovieClip on the stage (in my case, a health/HP bar). I made the health effect using a Document Class (HealthBar.as).
The question: What I'm trying to figure out now is how, in a totally separate .fla, to create multiple instances of these health bars and be able to access the methods in Document Class HealthBar.as from the Document Class in this new .fla
If I am doing this incorrectly in the first place, feel free to yell at me, and let me know how doing something like this SHOULD have been done.
Thanks for any help
You're halfway there with a document class. Now you just need to make it into a proper class in your com.domain.className (or drop the .as file into the same directory as your fla). While creating classfiles is trivial, online examples seem to muck it up, so here's Adobe's official demo (bleh).
That said, creating more healthbars basically looks like this...
Class
package {
public class HealthBar extends Sprite {
public function HealthBar() {
// constructor
trace("Healthbar created")
}
}
}
Document Code
import HealthBar;
for (var i:int = 0; i < 10; i++) {
var randomHealthBar:HealthBar = new HealthBar(); // <-- magic sauce
addChild(randomHealthBar);
}
// traces: "Healthbar created" 10 times
Shouldn't you be able to copy the movieclip from the healthbar .fla into your main .fla and then give it an actionscript linkage of HealthBar?
Then you should be able to call new HealthBar whenever you need one in your main file.
I'm having problems attaching MovieClips to different instances of a class. I'm kinda new to ActionScript 3, honestly, so this question might be a bit noobish. I did the research, though, but haven't found the kind of answer that I expected.
function AddNewElement(clip:MovieClip, array:Array, name:String, firstValue:int, secondValue:int):Element
As you may be able to guess, this is the function I made to create instances of a class in a dynamic way and add them to an array. I'm having problems with the very first parameter, though. How do I pass a MovieClip from my library to this function?
I saw a lot of answers to problems similar to this one stating that each MovieClip should be a class on its own, but since I have like forty MCs and I want to use them all for more or less the same thing I feel that it kills the purpose of classes, really.
How should I approach this?
First you need to give your library symbols unique class names from the linkage section while exporting or later from the "properties" option. You will see this input when you check the "Export for ActionScript" option there. Then you will need to instantiate your library symbol (with the new keyword) and cast it to MovieClip to pass to this function. So
AddNewElement(new LibrarySymbolClass() as MovieClip,[],'etc',0,0);
AddNewElement(MovieClip(new LibrarySymbolClass()),[],'etc',0,0);
will both let you do what you want.
However, since not all your library elements need to extend the MovieClip class, you would better pick DisplayObject instead of MovieClip. So a better version of your function would be
import flash.display.DisplayObject;
function AddNewElement(clip:DisplayObject, ...):* {
// some code here
return clip;
}
var clip:LibrarySymbolClass = AddNewElement(new LibrarySymbolClass() as DisplayObject,[],'etc',0,0);
trace(clip);
Using asterisk in the return value type will let it return the object with its right type (as [object LibrarySymbolClass] in this example).
Why not to create the movie clips on runtime, aka. creating them in the runtime execution context then instantiating each of them at the moment when you invoke the class. If each of the MC's is different, then either you create a MC class for each of them, giving them a name which end up in a ascending number, then using a for loop you put them in an array like so:
var mc_num:int = 40 // the number of MovieClips
var arr:Array = new Array();
for (var i:int=0; i < mc_num; i++) {
arr.push("myMovieClip" + String(i));
}
..then making reference to each of them by using the array index. I skip the part where you associate the images to MovieClips.
After that you invoke the desired MC as below:
var mc_1:MovieClip = arr[1] as MovieClip;
stage.addChild(mc_1);
When you create a MovieClip in Flash it gives you certain options, one of those options is for Flash to create a class for that MovieClip. That being said if you have that option applied to all forty movie clips then you create something like a master movie clip class and have each movie clip class extend the master movie clip class. The only thing is that you would have to create a .as file for each of your 40 movie clips and add extends MasterMovieClip to the class declaration. For example:
public class MasterMovieClip extends MovieClip {
// All of the variables and methods pertaining to each movie clip go here
}
Then each individual movie clip would resemble this class.
public class IndividualMovieClip_1 extends MasterMovieClip {
// Just include a constructor, even though you don't have to
}
Now all of your individual movie clips will have the same methods and variables, as long as said methods and variables are public, not private.
With this method you would have to create all 40 classes, however there might be a way in Flash when creating a new movie clip to set which class the movie clip extends and then you wouldn't have to create 40 different classes.
Update:
I re-read your question and thought of something else, that option I talked about in the first sentence, the one about Flash giving the option to create a class. Well if a class is not given then Flash will dynamically create a class at run-time. I think when it dynamically creates a class it does not maintain the same name as the library movie clip, so when your trying to pass the static name of your movie clip to your function, it has no clue what your talking about and throws a runtime error.
I am making an edutainment game using flash cs5, I'm really new at using flash, in fact we never yet tackle it at school, but I insist on learning about it.
In my codes, I encountered this error
C:\Users\acer\Desktop\JikanLibrary\Main.as, Line 16 1119: Access of possibly undefined property Click through a reference with static type Class.
This is the code I used in my program
package
{
import flash.display.MovieClip;
import flash.events.MouseEvent;
public class Main extends MovieClip
{
var startPage:StartPage;
var jikanBookshelf:JikanBookshelf;
public function Main()
{
startPage = new StartPage;
jikanBookshelf = new JikanBookshelf;
startPage.jikanBookshelf.addEventListener(MouseEvent.Click, onJikanBookshelf);
addChild(startPage);
function onJikanBookshelf(event:MouseEvent):void
{
addChild(jikanBookshelf);
removeChild(startPage);
}
}
}
}
The error is in this line
startPage.jikanBookshelf.addEventListener(MouseEvent.Click, onJikanBookshelf);
Since I'm really new at flash, I really don't know what went wrong with my codes, it was working a while ago before I put the mouse event. I hope someone could help me.
ActionScript is a case sensitive language. This means that Click is not the same as CLICK. So what you need here is MouseEvent.CLICK
"Why is CLICK all uppercase? Most property names aren't.", you might ask.
That's because CLICK is a static constant property of MouseEvent and the convention amongst ActionScript (and many other languages) programmers is that static constants are written in all uppercase to distinguish them visually from other variables.
'static' means it's a property of the MouseEvent class, not of an instance of MouseEvent.
'const' means it's not a variable: you can't change it's value.
It's a name conflict problem: The class definition name is same as the object name.
The problem in your script is that you have a class definition name startPage and you are trying to create an object of same name startPage.
You have to change the object name to something different. Let say startpage1.