XPCollection未加载

Question

我的一个类中有一个XPCollection。它是另一个类的XPCollection。当我运行应用程序时，XPCollection不会被加载。我可以在调试时在断点中清楚地看到它。这是我在我的对象中使用的代码。 ：

  private XPCollection<LimitAllocationTotals> _LimitAllocationTotals;

    public XPCollection<LimitAllocationTotals> LimitAllocationTotals   LimitAllocationTotals
    {
        get
        {


            if (LimitAllocations.IsLoaded && LimitAllocations != null)
            {
                UnitOfWork uow = new UnitOfWork();
                _LimitAllocationTotals = new XPCollection<LimitAllocationTotals>(uow, new BinaryOperator("Oid", Guid.Empty));
                _LimitAllocationTotals.Session = this.Session;
                foreach (LimitAllocation allocation in LimitAllocations)
                {
                    LimitAllocationTotals allocationTotals = new LimitAllocationTotals(this.Session);

                    allocationTotals.MTMLimit += allocation.MTMLimit;
                    allocationTotals.ARLimit += allocation.ARLimit;
                    allocationTotals.Volume += allocation.Volume;
                    allocationTotals.MaxTenor = allocation.MaxTenor;
                    allocationTotals.SourceEntity = allocation.SourceEntity;
                    allocationTotals.Commodity = allocation.Commodity;
                    allocationTotals.ConvertedVolume = allocation.ConvertedVolume;
                    _LimitAllocationTotals.Add(allocationTotals);

                }


                foreach (LimitExtension extension in LimitExtensions)
                {
                    if (extension.ExpirationDate >= DateTime.Now)
                    {
                        LimitAllocationTotals searchAllocation = null;
                        foreach (LimitAllocationTotals allocation in _LimitAllocationTotals)
                        {
                            if (allocation.SourceEntity != null && allocation.SourceEntity.Oid.Equals(extension.SourceEntity.Oid))
                            {
                                searchAllocation = allocation;
                                break;
                            }
                        }

                        if (searchAllocation == null)
                        {
                            searchAllocation = new LimitAllocationTotals(this.Session);
                            searchAllocation.SourceEntity = extension.SourceEntity;
                            _LimitAllocationTotals.Add(searchAllocation);
                        }

                        searchAllocation.MTMLimit += extension.MTMLimit;
                        searchAllocation.ARLimit += extension.ARLimit;
                        searchAllocation.Volume += extension.Volume;
                        searchAllocation.Commodity = extension.Commodity;
                        searchAllocation.MaxTenor += extension.MaxTenor;
                       // searchAllocation.CalculateMeasureConversion(_Commodity, _VolumeUnit);
                        //searchAllocation.VolumeUnit = extension.VolumeUnit;

                    }
                }
            }
            return _LimitAllocationTotals;
        }
        set
        {
            SetPropertyValue("LimitAllocationTotals", ref _LimitAllocationTotals, value);

        }
    }

Answer 1

按需加载XPCollection。来自the documentation：

  

在大多数情况下，需要创建一个集合来访问一个对象   数据存储中的特定类型。 XPCollection类实现   延迟加载，即它填充了来自的持久对象   按需存储数据。例如，您可以创建XPCollection   实例，标记为包含自定义Person对象。该   但是，集合将使用数据中的Person对象填充   仅在访问集合的内容时存储。

您可以通过调用XPCollection.Load()强制来自数据存储的加载，但通常是this should not be necessary。

Answer 2

您可以在OnLoaded方法上安全地初始化该集合，或者您可以在属性getter中检查IsLoading和IsSaving属性值，如果其中任何一个为true，则返回。只有当（IsLoading || IsSaving）== false时，您才能安全地从DB加载集合。

你可以尝试使用getter方法;

public XPCollection<LimitAllocationTotals> LimitAllocationTotals 
{
        get
        {
            if (IsLoading || IsSaving)
                return _LimitAllocationTotals;

            //  .... your codes
        }
}