画扇形代码

public static function DrawSector(graphics:Graphics,
								x:Number=200,
								y:Number=200,
								r:Number=100,
								angle:Number=27,
								startFrom:Number=270
								):void{
		    graphics.moveTo(x,y);
		    angle=(Math.abs(angle)>360)?360:angle;
		    var n:Number=Math.ceil(Math.abs(angle)/45);
		    var angleA:Number=angle/n;
		    angleA=angleA*Math.PI/180;
		    startFrom=startFrom*Math.PI/180;
		    graphics.lineTo(x+r*Math.cos(startFrom),y+r*Math.sin(startFrom));
		    for (var i:int=1; i<=n; i++) {
		        startFrom+=angleA;
		        var angleMid:Number=startFrom-angleA/2;
		        var bx:Number=x+r/Math.cos(angleA/2)*Math.cos(angleMid);
		        var by:Number=y+r/Math.cos(angleA/2)*Math.sin(angleMid);
		        var cx:Number=x+r*Math.cos(startFrom);
		        var cy:Number=y+r*Math.sin(startFrom);
		        graphics.curveTo(bx,by,cx,cy);
		    }
		    if (angle!=360) {
		        graphics.lineTo(x,y);
		    }

	}