Actionscript 3 在greensock LinePath2D中淡入淡出项目

这是LinePath2D类中提供的示例代码

import com.greensock.*;
import com.greensock.easing.*;
import com.greensock.motionPaths.*;
import flash.geom.Point;

//create a LinePath2D with 5 Points
var path:LinePath2D = new LinePath2D([new Point(0, 0), 
                                      new Point(100, 100), 
                                      new Point(350, 150),
                                      new Point(50, 200),
                                      new Point(550, 400)]);

//add it to the display list so we can see it (you can skip this if you prefer)
addChild(path);

//create an array containing 30 blue squares
var boxes:Array = [];
for (var i:int = 0; i < 30; i++) {
    boxes.push(createSquare(10, 0x0000FF));
}

//distribute the blue squares evenly across the entire path and set them to autoRotate
path.distribute(boxes, 0, 1, true);

//put a red square exactly halfway through the 2nd segment
path.addFollower(createSquare(10, 0xFF0000), path.getSegmentProgress(2, 0.5));

//tween all of the squares through the path once (wrapping when they reach the end)
TweenMax.to(path, 20, {progress:1});

//while the squares are animating through the path, tween the path's position and rotation too!
TweenMax.to(path, 3, {rotation:180, x:550, y:400, ease:Back.easeOut, delay:3});

//method for creating squares
function createSquare(size:Number, color:uint=0xFF0000):Shape {
    var s:Shape = new Shape();
    s.graphics.beginFill(color, 1);
    s.graphics.drawRect(-size / 2, -size / 2, size, size);
    s.graphics.endFill();
    this.addChild(s);
    return s;
}

淡入淡出元素的最简单方法是什么

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我应该在每个项目中添加一个tween，还是挂接到更新侦听器中？

我已经准备好了

        TweenMax.to(path, $speedNorm, { progress:1, ease:Linear.easeNone, repeat: -1, onUpdate:function():void
            {
                for (var j:int = 0; j < path.followers.length; j++) 
                {
                    var $follower:PathFollower = path.followers[j];
                    if ($follower.progress < 1/$numPoints) {
                        $follower.target.alpha = $follower.progress * $numPoints;
                    }
                    else if ($follower.progress > 1-1/$numPoints) {
                        $follower.target.alpha = (1-$follower.progress) * $numPoints;
                    }
                }
            }
        });

TweenMax.to（path，$speedNorm，{progress:1，ease:Linear.easeNone，repeat:-1，onUpdate:function（）：void
{
对于（var j:int=0；j1-1/$numPoints）{
$follower.target.alpha=（1-$follower.progress）*$numPoints；
}
}
}
});

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其中，$numpoints根据示例为30。我会做一个更新侦听器，因为它可能会稍微更有效。这是我正在尝试的方向，它有点困难，因为它需要更改/扩展LinePath2D类，以允许访问一些受保护的属性。看起来比我想象的要复杂。我不清楚你到底想做什么。你想让你的方块在到达你路径的尽头时分别淡入淡出吗？还是在这两个孩子开始和结束的同时？最好更新您的问题，使其更清晰地显示我确实需要的属性（追随者）已经公开。我确实在类中发现了一个小错误，但是，第一个和最后一个对象重叠（因为0和1的进度相同）最后一个对象不应添加或相应地调整位置。