as3.0画直线

import flash.display.Shape;
import flash.events.MouseEvent;
import flash.geom.Point;
var line:Shape;
var point:Point;
stage.addEventListener(MouseEvent.MOUSE_DOWN,drawBegin);
stage.addEventListener(MouseEvent.MOUSE_UP,drawEnd);

function drawBegin(e:MouseEvent):void {
    line= new Shape();
    addChild(line);
    point = new Point(mouseX,mouseY);
    stage.addEventListener(MouseEvent.MOUSE_MOVE,drawing);
}
function drawing(e:MouseEvent):void {
    line.graphics.clear();
    line.graphics.moveTo(point.x,point.y);
    line.graphics.lineStyle(2,0);
    line.graphics.lineTo(mouseX,mouseY);
    e.updateAfterEvent();
}
function drawEnd(e:MouseEvent):void {
    stage.removeEventListener(MouseEvent.MOUSE_MOVE,drawing);
}