Fresh PanelSet的子计数为2

Question

我试图创建一个OverhangPanelSetScene，几乎在其中创建一个设置页面。

在进行任何修改之前，我注意到

print "PANEL SET SIZE", m.top.panelSet.getChildCount()

返回2的大小，但是由于没有创建或附加已定义的任何子代，因此我看不到这是怎么回事。

有什么作用？

添加了两个项目：

ITEM            <Component: roSGNode:Poster> =
{
    audioGuideText: ""
    bitmap: <Component: roSGNode:Bitmap>
    bitmapHeight: 45
    bitmapMargins: <Component: roAssociativeArray>
    bitmapWidth: 45
    blendColor: -1
    enableColorBlending: false
    failedBitmap: <Component: roInvalid>
    failedBitmapOpacity: 1
    failedBitmapUri: ""
    height: 0
    loadDisplayMode: "noscale"
    loadHeight: 0
    loadingBitmap: <Component: roInvalid>
    loadingBitmapOpacity: 1
    loadingBitmapUri: ""
    loadStatus: "ready"
    loadSync: false
    loadWidth: 0
    uri: ""
    width: 0
    childRenderOrder: "last"
    clippingRect: <Component: roAssociativeArray>
    enableRenderTracking: false
    inheritParentOpacity: true
    inheritParentTransform: true
    muteAudioGuide: false
    opacity: 1
    renderPass: 4
    renderTracking: "disabled"
    rotation: 0
    scale: <Component: roArray>
    scaleRotateCenter: <Component: roArray>
    translation: <Component: roArray>
    visible: false
    change: <Component: roAssociativeArray>
    focusable: false
    focusedChild: <Component: roInvalid>
    id: ""
}

ITEM            <Component: roSGNode:Poster> =
{
    audioGuideText: ""
    bitmap: <Component: roSGNode:Bitmap>
    bitmapHeight: 45
    bitmapMargins: <Component: roAssociativeArray>
    bitmapWidth: 45
    blendColor: -1
    enableColorBlending: false
    failedBitmap: <Component: roInvalid>
    failedBitmapOpacity: 1
    failedBitmapUri: ""
    height: 0
    loadDisplayMode: "noscale"
    loadHeight: 0
    loadingBitmap: <Component: roInvalid>
    loadingBitmapOpacity: 1
    loadingBitmapUri: ""
    loadStatus: "ready"
    loadSync: false
    loadWidth: 0
    uri: ""
    width: 0
    childRenderOrder: "last"
    clippingRect: <Component: roAssociativeArray>
    enableRenderTracking: false
    inheritParentOpacity: true
    inheritParentTransform: true
    muteAudioGuide: false
    opacity: 1
    renderPass: 4
    renderTracking: "disabled"
    rotation: 0
    scale: <Component: roArray>
    scaleRotateCenter: <Component: roArray>
    translation: <Component: roArray>
    visible: false
    change: <Component: roAssociativeArray>
    focusable: false
    focusedChild: <Component: roInvalid>
    id: ""
}

编辑：

我可以使用面板集通过ScenegraphTutorial确认这一点。初始化后，面板集中有两个孩子。初始化后，有4个孩子。