[ActionScript 3.0] 动态绘制扇形实例（拖拽绘制）

  1 package
  2 {
  3     import flash.display.Shape;
  4     import flash.display.Sprite;
  5     import flash.events.MouseEvent;
  6     
  7     /**
  8      * @author Frost.Yen
  9      * @E-mail 871979853@qq.com
 10      * @create 2015-7-13 上午11:14:16
 11      *
 12      */
 13     [SWF(width="800",height="600")]
 14     public class DrawSectorTest extends Sprite
 15     {
 16         private var _sector:Sprite;
 17         private var _dragSp:Sprite;
 18         private var _radian:Number;//弧度
 19         private const _radius:uint = 100;//半径
 20         private const _angle:Number = 60;//初始角度
 21         public function DrawSectorTest()
 22         {
 23             _sector = new Sprite();
 24             _dragSp = new Sprite();
 25             _sector.x = _dragSp.x = stage.stageWidth*0.5;
 26             _sector.y = _dragSp.y = stage.stageHeight*0.5;
 27             this.addChild(_sector);
 28             this.addChild(_dragSp);
 29             
 30             
 31             _dragSp.graphics.beginFill(0,.2);
 32             _dragSp.graphics.drawRect(0,-5,_radius,10);
 33             _dragSp.graphics.endFill();
 34             
 35             drawSector(_sector,0,0,_radius,_angle,0);
 36             _dragSp.rotation = _angle;
 37             _dragSp.addEventListener(MouseEvent.MOUSE_DOWN,onDragDown);
 38         }
 39         private function onDragDown(e:MouseEvent):void
 40         {
 41             stage.addEventListener(MouseEvent.MOUSE_MOVE,onDragMove);
 42             stage.addEventListener(MouseEvent.MOUSE_UP,onDragOut);
 43         }
 44         private function onDragMove(e:MouseEvent):void
 45         {
 46             _dragSp.rotation = Math.atan2(_dragSp.parent.mouseY - _dragSp.y,_dragSp.parent.mouseX - _dragSp.x) * 180 / Math.PI ;
 47             _radian = (_dragSp.rotation) * Math.PI / 180;
 48             /**这是关键，因为rotation的区间是[0,180][0,-180],如果直接用_dragSp.rotation会导致拖拽绘制扇形错误*/
 49             if (_dragSp.rotation > 180){
 50                 _radian = _radian + Math.PI;
 51             }
 52             if (_radian < 0){
 53                 _radian = _radian + 2 * Math.PI;
 54             }
 55             drawSector(_sector,0,0,_radius,_radian*180/Math.PI,0);
 56         }
 57         private function onDragOut(e:MouseEvent):void
 58         {
 59             stage.removeEventListener(MouseEvent.MOUSE_MOVE,onDragMove);
 60             stage.removeEventListener(MouseEvent.MOUSE_UP,onDragOut);
 61             
 62         }
 63         /**
 64          * 绘制扇形
 65          * @param    mc 承载扇形的对象
 66          * @param    x 圆心角x
 67          * @param    y 圆心角y
 68          * @param    r 半径
 69          * @param    angle 绘制角度
 70          * @param    startFrom 起始角度
 71          * @param    color 填充颜色
 72          * @param    hasFrame 是否填充边框
 73          */
 74         private function drawSector(sp:Sprite,x:Number=0,y:Number=0,r:Number=100,angle:Number=60,startAngle:Number=0,color:Number=0xff0000,hasFrame:Boolean=true):void {
 75             sp.graphics.clear();
 76             if(hasFrame) {
 77                 sp.graphics.lineStyle(0,0xffff00);
 78             }
 79             sp.graphics.beginFill(color,1);
 80             sp.graphics.moveTo(x,y);
 81             angle=(Math.abs(angle)>360)?360:angle;
 82             var n:Number=Math.ceil(Math.abs(angle)/45);
 83             var angleA:Number=angle/n;
 84             angleA=angleA*Math.PI/180;
 85             startAngle=startAngle*Math.PI/180;
 86             sp.graphics.lineTo(x+r*Math.cos(startAngle),y+r*Math.sin(startAngle));
 87             for (var i:int=1; i<=n; i++) {
 88                 startAngle+=angleA;
 89                 var angleMid:Number=startAngle-angleA/2;
 90                 var bx:Number=x+r/Math.cos(angleA/2)*Math.cos(angleMid);
 91                 var by:Number=y+r/Math.cos(angleA/2)*Math.sin(angleMid);
 92                 var cx:Number=x+r*Math.cos(startAngle);
 93                 var cy:Number=y+r*Math.sin(startAngle);
 94                 sp.graphics.curveTo(bx,by,cx,cy);
 95             }
 96             if (angle!=360) {
 97                 sp.graphics.lineTo(x,y);
 98             }
 99             sp.graphics.endFill();
100         }
101     }
102 }