【发布时间】：2011-02-21 06:35:08
【问题描述】：
我正在尝试对 linq 问题进行排序。 我正在将数据绑定到 silverlight telerik silverlight 图表，但运气不佳。我可以让图形使用硬编码值，但是当我尝试将它绑定到数据库时，没有返回任何数据。
这会返回预期的数据。
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;
}
}
像这样绑定图表
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();
没有返回任何东西。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。
我假设使用 observablecollection 的第一种方法与仅使用 tolist() 的第二种方法是原因。
我需要改变什么？
【问题讨论】：
-
你为什么选择
RewardTransactionDetail类型的数据，而你的列表采用TransactionDetail类型.. 他们是否共享任何继承关系 -
这里有严重问题。您没有在第二个示例中使用
data。而group.ToList()将返回一个List<RewardTransactionDetail>。无法与您的第一个样本进行直接比较。 -
嘿 Ani 对不起，我复制不正确。现已更新
-
你们是否曾经为自己的问题创建一个简单的代码示例，或者只是复制粘贴 100 多行未知的类、函数，甚至与所提出的问题无关？
标签： c# silverlight linq