Question

ActionScript3.0直线编程，求帮助！

两个点，我现在只会用linestyle编程实现在两点间创建一条直线，现在想要从一点到另一点慢慢出现一条直线(就像有一只看不见的笔在画一样)，该怎么实现啊？

Answer 1

var firstPoint:Point = new Point(10,20);//你的第一个点
var secondPoint:Point = new Point(100,200);//你的第二个点
var dT:uint = 30;//绘制直线的间隔时间
var drawTimes:uint = 50;//绘制直线的线段数，总共执行的时间就是drawTimes * dT
var myTimer:Timer = new Timer(dT, drawTimes);
var curTimes:uint = 0;//当前画线的次数
var dXY:Point = new Point((secondPoint.x - firstPoint.x)/drawTimes, (secondPoint.y - firstPoint.y)/drawTimes);//平均每次画线的移动距离
myTimer.addEventListener(TimerEvent.TIMER, onTimerHandler);
var lineShape:Shape = new Shape();//直线
lineShape.graphics.moveTo(firstPoint.x, firstPoint.y);
addChild(lineShape);
myTimer.start();

function onTimerHandler(e:TimerEvent):void
{
curTimes++;
lineShape.graphics.lineTo(firstPoint.x + dXY.x * curTimes, firstPoint.y + dXY.y * curTimes);
}

Answer 2

用ENTER-FRAME事件的侦听，侦听器里写graphics.clear然后graphics.lineTo一个向终点方向位移少许的新位置。代码：
var p1:Point=new Point(100,100);
var p2:Point=new Point(200,200);
var counter:int=0;
var repeat:int=100;
var s:Sprite=new Sprite;
addChild(s);
stage.addEventListener(Event.ENTER_FRAME,handler);
function handler(e:Event){
if(counter++>repeat){
stage.removeEventListener(Event.ENTER_FRAME,handler);
return;
}
s.graphics.clear();
s.graphics.lineStyle(0,0);
s.graphics.moveTo(p1.x,p1.y);
s.graphics.lineTo(p1.x+(p2.x-p1.x)*counter/repeat),p1.y+(p2.y-p1.y)*counter/repeat);
}