Bước 1:
_ Tạo FLA Document “AutoTrailEffect.fla”
_ Tạo movieClip đặt tên linkage là “Clip”.
Bước 2:
_ Tạo file “AutoTrailEffect.as” trong thư mục “com”
CODE:
package com {
import flash.display.MovieClip;
import flash.events.Event;
/**
* @author yoko
*/
public class AutoTrailEffect extends MovieClip {
private const RADIUS : int = 120;
private const FRICTION : Number = .95;
public function AutoTrailEffect() {
stage.frameRate = 24;
createClip();
}
private function createClip() : void {
var CLIP : MovieClip = new Clip() as MovieClip;
CLIP.x = stage.stageWidth / 2 + Math.cos(CLIP.angle * 2) * RADIUS;
CLIP.y = stage.stageHeight / 2 + Math.sin(CLIP.angle * 3) * RADIUS;
CLIP.angle = 0;
addChild(CLIP);
CLIP.addEventListener(Event.ENTER_FRAME, playClip);
}
private function playClip(evt : Event) : void {
evt.target.x = stage.stageWidth / 2 + Math.cos(evt.target.angle * 2) * RADIUS;
evt.target.y = stage.stageHeight / 2 + Math.sin(evt.target.angle * 3) * RADIUS;
evt.target.angle += .05;
var copy_mc : MovieClip = new Clip() as MovieClip;
copy_mc.x = evt.target.x;
copy_mc.y = evt.target.y;
addChild(copy_mc);
copy_mc.addEventListener(Event.ENTER_FRAME, playClipCopy);
}
private function playClipCopy(evt : Event) : void {
evt.target.alpha *= FRICTION;
evt.target.scaleY = evt.target.alpha;
if(evt.target.alpha <= .3) {
evt.target.removeEventListener(Event.ENTER_FRAME, playClip);
}
}
}
// end class
}
Bước 3:
_ Mở file “AutoTrailEffect.fla” gõ đoạn code com.AutoTrailEffect vào Document class
_ Lưu lại xem kết quả
