如何在 AIR Android 应用程序中平滑滚动内容？

Question

我写了一个小的 class 用于在移动设备上滚动内容。 class 工作正常，但滚动感觉不流畅。这是 class:

package  {
import flash.display.Sprite;
import flash.display.InteractiveObject;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.display.InteractiveObject;
import flash.geom.Rectangle;
import com.greensock.TweenMax;
import com.greensock.easing.*;
import flash.utils.setTimeout;

public class FlickScroll extends Sprite {

    private var currentY:Number;
    private var lastY:Number;
    private var vy:Number;
    public var clickable:Boolean = true;
    private var dragging:Boolean = false;
    private var firstY:Number;
    private var secondY:Number;
    private var content:InteractiveObject;
    private var masker:InteractiveObject;
    private var topBounds:Number;
    private var bottomBounds:Number;
    private var Offset:Number;
    public var friction:Number = .90;
    public var flickable:Boolean = false;
    public var scrollVelocity:Number;

    public function FlickScroll(Masker:InteractiveObject, Content:InteractiveObject, TopBounds:Number, BottomBounds:Number) {
        masker = Masker;
        content = Content;
        topBounds = TopBounds;
        bottomBounds = BottomBounds;

        this.addEventListener(Event.ADDED_TO_STAGE, onAddedToStage, false, 0, true);
    }
    private function onAddedToStage(evt:Event):void
    {
        init();
        this.removeEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
        addEventListener(Event.ENTER_FRAME, onLoop, false, 0, true);

        content.mask = masker;
        content.cacheAsBitmap = true;
    }
    private function init():void
    {
        currentY = content.y;
        lastY = content.y;
        vy = 0;
        scrollVelocity = 2;
        content.addEventListener(MouseEvent.MOUSE_DOWN, onContentDown, false, 0, true);
    }
    private function onContentDown(evt:MouseEvent):void
    {

        firstY = content.y;
        Offset = content.mouseY;
        trace(mouseY, Offset, mouseY - Offset);

        content.addEventListener(MouseEvent.MOUSE_MOVE, onContentMove, false, 0, true);
        stage.addEventListener(MouseEvent.MOUSE_UP, onContentUp, false, 0, true);
    }
    private function onContentMove(evt:MouseEvent):void
    {

        dragging = true;
        clickable = false;
        content.y = mouseY - Offset;


        if(content.y > topBounds + 200)
        {
            content.y = topBounds + 200;
        }
        else if(content.y < bottomBounds - 200)
        {
            content.y = bottomBounds - 200;
        }



        trace("ContentY: ", content.y, "Bottom Bounds: ", bottomBounds, "Top Bounds: ", topBounds);

        evt.updateAfterEvent();
    }
    private function onContentUp(evt:MouseEvent):void
    {
        secondY = content.y;
        var dy:Number = secondY - firstY;

        if(dy < 20 && dy > -20)
        {
            clickable = true;
        }

        if(content.y > this.topBounds)
        {
            TweenMax.to(content, .4, {y:topBounds, ease:Expo.easeOut});
        }
        else if( content.y < this.bottomBounds)
        {
            TweenMax.to(content, .4, {y:bottomBounds, ease:Expo.easeOut});
        }
        else
        {
            dragging = false;
        }
        //setTimeout(setDraggingFalse, 400);


        content.removeEventListener(MouseEvent.MOUSE_MOVE, onContentMove);
        content.removeEventListener(MouseEvent.MOUSE_UP, onContentUp);
    }
    private function onLoop(evt:Event):void
    {
        if(this.flickable)
        {

            if(dragging)
            {
                lastY = currentY;
                currentY = mouseY;
                vy = (currentY - lastY)/scrollVelocity;
            }
            else
            {
                content.y += vy;
                vy *= friction;
            }
        }

        if(!dragging)
        {
            if(content.y > topBounds)
            {
                content.y = topBounds;
            }
            else if(content.y < bottomBounds)
            {
                content.y = bottomBounds;
            }
        }
    }
    public function updateBounds(top:Number, bottom:Number):void
    {
        bottomBounds = bottom;
        topBounds = top;
    }

    private function setDraggingFalse():void
    {
        dragging = false;
    }

}

}

抱歉，代码真的很乱。我可以采取哪些步骤使滚动感觉更流畅？任何帮助是极大的赞赏。

Answer 1

如果您使用的是位图，请尝试遵循 this 指南。它处理位图的平滑滚动。

如果您正在处理动画片段，startDrag() 和 stopDrag() 也不错。也许添加一个 Tween 并根据鼠标最后 y 和当前 y 的逐帧比较对其进行减速，以在释放鼠标时获得 "thrust"。可能必须在鼠标移动事件上锁定影片剪辑的 x 位置（或 y 位置，具体取决于您希望它如何滚动）。

如何在 AIR Android 应用程序中平滑滚动内容？

How to smoothly scroll content in an AIR Android Application?

air

actionscript-3