Question

我正在尝试在ADG上实现延迟加载。而且我陷入了需要将返回的子节点添加到展开节点的程度。

目前我在做：

private function childrenloaded(data:*,item:*):void
{
    var len:int = data.length;
    for(var i=0;i<len;i++)
        (internalMainGrid.dataProvider as HierarchicalCollectionView).addChild(item, data[i]);
}

这很好，但速度很慢。（共计21,990毫秒：919条记录）有什么方法可以加快速度吗？ - 比如直接设置孩子Ex：

var d:LazyHierarchicalData = (internalMainGrid.dataProvider as HierarchicalCollectionView).source as LazyHierarchicalData;
var ind:int = (d.source as RemoteCursorArray).getItemIndex(item);
(d.source as RemoteCursorArray)[ind].children = data;
(d.source as RemoteCursorArray).dispatchEvent(new CollectionEvent(CollectionEvent.COLLECTION_CHANGE));

但这并没有让人耳目一新。

欢迎任何帮助或指导更好的解决方案。提前谢谢！

Answer 1

我做了同样的事情。从我发现 - 使用GroupingCollection（2）和/或SummaryRow真的减慢了它。更不用说在特定节点获取新数据时重置整个树的开放关闭。

从烟雾测试性能来看，拉动/涂抹~2000行需要大约5秒钟。现在每个节点100-200行需要大约1/2秒或更少（不计算首次调用ADG到屏幕时的初始绘制延迟）。

对我来说，我做了以下事情：

扩展HierarchicalData以根据每次从数据库中获取的摘要数据来定制子节点何时存在，并指定哪个属性包含要显示的子项（如果与子属性不同） - 我这样做这是因为我在RobotLegs MVC平台中使用的模型。
扩展AdvancedDataGridGroupItemRenderer以直观地更改公开图标（三角图形）的颜色 - 让用户知道需要提取哪些元素与已有数据的节点。将其分配给groupItemRenderer属性。
使用AdvancedDataGridEvent.ITEM_OPEN侦听器调度包含event.item属性的事件，以便命令＆gt;服务＆gt;响应者在UI请求的确切节点处更新模型（添加到children属性）。
将适当的CollectionChangeEvent添加到顶级集合（它的子节点是ArrayCollections - 嵌套集合不绑定）
在响应者声明完成后调用dataprovider刷新方法。

下面的伪示例：

//Listener on Grid:
protected function onLedgerOpenSummaryNode(event:AdvancedDataGridEvent):void 
{
    trace('LedgerMediator.onLedgerOpenSummaryNode', event.item);

    if (event.item is SummaryTransaction)
    {
        refreshed = false;
        sumTrans = event.item as SummaryTransaction;
        //note - in my service responder I add the resulting db rows to the event.item
        dispatch(new AccountEvent(AccountEvent.SUMMARY_DETAIL, null, account, event.item as SummaryTransaction));
    }
}

//Dataprovider assignment to grid
private function get dataProvider():HierarchicalCollectionView
{
    if (!groupCollection)
    {
        groupCollection = new HierarchicalCollectionView();
        groupCollection.source = new OnDemandCollection();
    }

    return groupCollection;
}

//assigns the initial source to the demand collection
private function loadTransactions():void
{
    var odc:OnDemandCollection = OnDemandCollection(dataProvider.source);
        odc.source = account.summaryTransactions.children;

    transactionChangeDetection(true);
    view.callLater(deferrDataProviderUpdate);
}

//called when the service.responder dispatches it's 'complete event'.
private function deferrDataProviderUpdate():void 
{
    if (refreshed) return;
    dataProvider.refresh(); 
}

//add change event listener to the top-level collection
private function transactionChangeDetection(add:Boolean):void
{
    var collection:ArrayCollection;
    //nested collections are not binding up the object chain, so change listeners must be added/removed to/from each collection.
    for each ( var summary:SummaryTransaction in account.summaryTransactions.collection)
    {
        collection = summary.transactions.collection;
        add ? collection.addEventListener(CollectionEvent.COLLECTION_CHANGE, onTransactionUpdate)
            : collection.removeEventListener(CollectionEvent.COLLECTION_CHANGE, onTransactionUpdate);
    }
}

//block the refresh method - only interested in add,delete,update
protected function onTransactionUpdate(event:CollectionEvent):void 
{
    if (event.kind == CollectionEventKind.REFRESH) return;
    view.callLater(deferrDataProviderUpdate);
}


public class ExtAdvancedDataGridGroupItemRenderer extends AdvancedDataGridGroupItemRenderer 
{
    private var defaultColor:ColorTransform;

    public function ExtAdvancedDataGridGroupItemRenderer() 
    {
        super();
    }

    override protected function commitProperties():void 
    {
        super.commitProperties();
        if (disclosureIcon) defaultColor = disclosureIcon.transform.colorTransform;
    }

    override protected function updateDisplayList(w:Number, h:Number):void 
    {
        super.updateDisplayList(w, h);

        if (!listData || !data) return;

        var adgld:AdvancedDataGridListData = AdvancedDataGridListData(listData);
        var adg:AdvancedDataGrid = adgld.owner as AdvancedDataGrid;
        var hcv:HierarchicalCollectionView = adg.dataProvider as HierarchicalCollectionView;
        var source:IHierarchicalData = hcv.source;

        var useDefaultColor:Boolean;
        var visible:Boolean;
        if (!data) visible = false;
        else if (!source.canHaveChildren(data)) visible = false;
        else if (source.hasChildren(data)) 
        {
            useDefaultColor = true;
            visible = true;
        }
        else
        {
            visible = true;

            var ct:ColorTransform = new ColorTransform();
                ct.color = 0xBCB383;
            disclosureIcon.transform.colorTransform = ct;
        }

        if (useDefaultColor) disclosureIcon.transform.colorTransform = defaultColor;
        disclosureIcon.visible = visible;
    }
}

public class OnDemandCollection extends HierarchicalData
{

    public function OnDemandCollection() 
    {
        super();
    }


    override public function getChildren(node:Object):Object 
    {
        if (node is SummaryGrouping) return SummaryGrouping(node).children;
        else if (node is SummaryTransaction) return SummaryTransaction(node).children;
        else if (node is Transaction) return Transaction(node).children;

        return {};
    }

    override public function canHaveChildren(node:Object):Boolean 
    {
        if (node is SummaryGrouping)
        {
            return true;
        }
        else if (node is SummaryTransaction)
        {
            var sumTran:SummaryTransaction = SummaryTransaction(node);
            return sumTran.numTransactions > 0;
        }
        else if (node is Transaction)
        {
            var tran:Transaction = Transaction(node);
            return tran.isSplit;
        }
        else if (node is Split) return false;
        else if (node.hasOwnProperty('children'))
        {
            var list:IList = node['children'] as IList;
            return list.length > 0;
        }
        else return false;
    }
}

Answer 2

您应该从collection_change发送internalMainGrid.dataProvider个事件来触发视图中的更改或调用refresh()方法（它属于ICollectionView，由{HierarchicalCollectionView实现1}}作为IHierarchicalCollectionView）的实现者，在同一个dataProvider上。

将子项添加到Hierarchical CollectionView

2 个答案: