Flash CS3轻松制作一个简单的弹性跟随鼠标特效

这个动画非常简单，只是有一个圆永远跟随鼠标，而且还有弹性！Flash CS3轻松制作一个简单的弹性跟随鼠标特效。
具体制作说明，使用Flash CS3来实现，用的也是ActionScript 3.0，您如果不懂可以查看本站相关教程。
   新建立一个文档(File > New > ActionScript 3.0)，然后保存为demo.fla，然后按Ctrl+F3打开属性面板，设置帧频为30fps，document class主类为demo。
   然后设置as，打开文本编辑，把下面代码保存为demo.as。
package {
  import flash.display.Shape;
  import flash.display.Sprite;
  import flash.events.Event;
  import flash.ui.Mouse;
  public class SproingDemo extends Sprite {
    private var orb1:Shape;
    private var orb2:Orb;
    private var lineCanvas:Shape;
    private var spring:Number = .1;
    private var damping:Number = .9;
    // Constructor
    public function SproingDemo() {
      init();
    }
    private function init():void {
      // Set up the small orb
      orb1 = new Shape();
      orb1.graphics.lineStyle(1, 0x6633CC);
      orb1.graphics.beginFill(0x6699CC);
      orb1.graphics.drawCircle(0, 0, 10);     
      // Set up the large orb
      orb2 = new Orb(25, 0x00CCFF, 1, 0x0066FF);
      // Set up the drawing canvas for the line drawn between the orbs
      lineCanvas = new Shape();     
      // Add lineCanvas, orb1 and arb2 to this object's display hierarchy
      addChild(orb2);
      addChild(orb1);
      addChild(lineCanvas);     
      // Register for Event.ENTER_FRAME events
      addEventListener(Event.ENTER_FRAME, enterFrameListener);     
      // Hide the mouse pointer
      Mouse.hide();
    }
    private function enterFrameListener(e:Event):void {
      // Set orb1's position to current mouse position
      orb1.x = mouseX;
      orb1.y = mouseY;   
      // Spring orb2 to orb1
      orb2.vx += (orb1.x - orb2.x) * spring;
      orb2.vy += (orb1.y - orb2.y) * spring;
      orb2.vx *= damping;
      orb2.vy *= damping;
      orb2.x += orb2.vx;
      orb2.y += orb2.vy;     
      // Draw a line between the two orbs
      drawLine();
    }   
    private function drawLine():void {
      with (lineCanvas) {
        graphics.clear();
       graphics.moveTo(orb1.x, orb1.y);
       graphics.lineStyle(1, 0x4C59D8);
        graphics.lineTo(orb2.x, orb2.y);
      }
    }
  }
}
然后再建立一个Orb.as，内容如下。
package {
  import flash.display.Shape;
 
  public class Orb extends Shape {
    internal var radius:int;
    internal var vx:Number = 0;
    internal var vy:Number = 0;
    // Constructor
    public function Orb(radius:int = 20, fillColor:int = 0x00FF00, lineThickness:int = 1, lineColor:int = 0) {
      this.radius = radius;
      graphics.lineStyle(lineThickness, lineColor);
      graphics.beginFill(fillColor);
      graphics.drawCircle(0, 0, radius);
    }
  }
}