[英]Cannot convert source type to System.Nullable<double>
这是我的脚本:
public PlainBrgDataSummaryComplete SummaryComputationPerTransSQLite(long ProgramID)
{
PlainBrgDataSummaryComplete result = new PlainBrgDataSummaryComplete();
DataSet dataSet = GetPlainBrgDataSQLite(ProgramID);
var abcde = dataSet.Tables["dataBridge"]
.AsEnumerable()
//.Where(a => Convert.ToDateTime(a["reportingDate"].ToString()) >= startOfWeek1 && Convert.ToDateTime(a["reportingDate"].ToString()) < endOfWeek1.AddDays(1))
.GroupBy(a => 1)
.Select(d =>
new PlainBrgDataSummaryTrans
{
transactionWk6 = d.Sum(a => a.Field<double?>("TranCount"))
}
).FirstOrDefault();
result.totaltransaction = new PlainBrgDataSummaryTrans
{
transactionWk6 = abcde;
};
return result;
}
我收到错误消息-无法将源类型转换为System.Nullable<double>
。 特别是在一部分上, transactionWk6 = abcde
;
abcde
已经是PlainBrgDataSummaryTrans
类型,因为您正在将select
语句投影到该类型。
尝试像这样使用它:
result.totaltransaction = abcde;
return result;
Mihail Stancescu应该解决这个问题。 但是,考虑您的退货类型,您不需要额外的分配。 您可以像下面这样更改代码
public PlainBrgDataSummaryComplete SummaryComputationPerTransSQLite(long ProgramID)
{
DataSet dataSet = GetPlainBrgDataSQLite(ProgramID);
return dataSet.Tables["dataBridge"]
.AsEnumerable()
//.Where(a => Convert.ToDateTime(a["reportingDate"].ToString()) >= startOfWeek1 && Convert.ToDateTime(a["reportingDate"].ToString()) < endOfWeek1.AddDays(1))
.GroupBy(a => 1)
.Select(d =>
new PlainBrgDataSummaryTrans
{
transactionWk6 = d.Sum(a => a.Field<double?>("TranCount"))
}
).FirstOrDefault();
}
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