c# - 将 linq 查询转换为 observablecollection

Question

我正在尝试对 linq 问题进行排序。我将数据绑定(bind)到 silverlight telerik silverlight 图，但运气不佳。我能够使图形与硬编码值一起使用，但是当我尝试将它绑定(bind)到数据库时，没有返回任何数据。

这将返回预期的数据。

  public class TranactionDetail
{
    public DateTime TransactionDate { get; set; }
    public int TransactionType { get; set; }
    public double TransactionAmount { get; set; }
    public int Month{ get; set; }
    public string MonthName { get; set; }
    public double TransactionCount { get; set; }


    public static ObservableCollection<TranactionDetail> GetTransactions(int transactionType)
    {
        ObservableCollection<TranactionDetail> data;


        if (transactionType == 1)
        {
            data = new ObservableCollection<TranactionDetail>()
                       {
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 11,Month = DateTime.Now.AddMonths(1).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 3,Month = DateTime.Now.AddMonths(2).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(3).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(4).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(5).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 12,Month = DateTime.Now.AddMonths(6).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(7).Month,TransactionType = 1} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(8).Month,TransactionType = 1} ,
                       };

        }
        else 
        {
            data = new ObservableCollection<TranactionDetail>()
            {
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(1).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 2,Month = DateTime.Now.AddMonths(2).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 5,Month = DateTime.Now.AddMonths(3).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(4).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(5).Month,TransactionType =2} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(6).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 1,Month = DateTime.Now.AddMonths(7).Month,TransactionType = 2} ,
                        new TranactionDetail(){TransactionAmount = 7,Month = DateTime.Now.AddMonths(8).Month,TransactionType = 2} ,
            };
        }
        return data;
    }
}

像这样绑定(bind)图形

   List<ObservableCollection<TransactionDetail>> data = new List<ObservableCollection<ransactionDetail>>();
        data.Add(TransactionDetail.GetTransactions(1));
        data.Add(TransactionDetail.GetTransactions(3));         
        this.radChart.ItemsSource = data;

XAML

<telerik:RadChart x:Name="radChart">
        <telerik:RadChart.DefaultView>
            <telerik:ChartDefaultView>
                <telerik:ChartDefaultView.ChartTitle>
                    <telerik:ChartTitle Content="Transaction Data" />
                </telerik:ChartDefaultView.ChartTitle>

            </telerik:ChartDefaultView>
        </telerik:RadChart.DefaultView>
        <telerik:RadChart.SeriesMappings>
            <telerik:SeriesMapping LegendLabel="Processed" CollectionIndex="0">
                <telerik:SeriesMapping.SeriesDefinition>
                    <telerik:LineSeriesDefinition ShowItemLabels="True" />
                </telerik:SeriesMapping.SeriesDefinition>
                <telerik:SeriesMapping.ItemMappings>
                    <telerik:ItemMapping DataPointMember="YValue" FieldName="TransactionAmount" />
                    <telerik:ItemMapping DataPointMember="XValue" FieldName="Month" />
                </telerik:SeriesMapping.ItemMappings>
            </telerik:SeriesMapping>
            <telerik:SeriesMapping LegendLabel="Redeemed" CollectionIndex="1">
                <telerik:SeriesMapping.SeriesDefinition>
                    <telerik:LineSeriesDefinition ShowItemLabels="True" />
                </telerik:SeriesMapping.SeriesDefinition>
                <telerik:SeriesMapping.ItemMappings>
                    <telerik:ItemMapping DataPointMember="YValue" FieldName="TransactionAmount" />
                    <telerik:ItemMapping DataPointMember="XValue" FieldName="Month"  />
                </telerik:SeriesMapping.ItemMappings>
            </telerik:SeriesMapping>
        </telerik:RadChart.SeriesMappings>
    </telerik:RadChart>

现在，如果我尝试将数据绑定(bind)到实际数据，例如

 var grouped = from t in TransctionData
                      group t by new
                      {
                          t.PurchaseDate.Value.Month
                      }
                          into g
                          select new TransactionDetail()
                          {
                              Month = g.Select((n => n.PurchaseDate.Value.Month)).First(),
                              TransactionAmount = g.Count()
                          };


        List<ObservableCollection<TransactionDetail>> data = new     List<ObservableCollection<TransactionDetail>>();
        this.radChart.ItemsSource = grouped.ToList();

没有返回任何内容。我已经放置了一个断点，我可以看到这是分组内的值，它们看起来确实像 TransactionDetail。

我假设第一个方法使用 observablecollection 而第二个方法只使用 tolist() 是原因。

我需要改变什么？

Answer 1

你好。而不是使用 .ToList()你能用 List 转换“分组”吗？

this.radChart.ItemsSource = (List<ObservableCollection<TransactionDetail>>)grouped;

谢谢