linq GroupJoin を作成しようとしていますが、前述のエラーが発生します。これがコードです
public Dictionary<string, List<QuoteOrderline>> GetOrderlines(List<string> quoteNrs)
{
var quoteHeadersIds = portalDb.nquote_orderheaders
.Where(f => quoteNrs.Contains(f.QuoteOrderNumber))
.Select(f => f.ID).ToList();
List<nquote_orderlines> orderlines = portalDb.nquote_orderlines
.Where(f => quoteHeadersIds.Contains(f.QuoteHeaderID))
.ToList();
var toRet = quoteNrs
.GroupJoin(orderlines, q => q, o => o.QuoteHeaderID, (q => o) => new
{
quoteId = q,
orderlines = o.Select(g => new QuoteOrderline()
{
Description = g.Description,
ExtPrice = g.UnitPrice * g.Qty,
IsInOrder = g.IsInOrder,
PartNumber = g.PartNo,
Price = g.UnitPrice,
ProgramId = g.ProgramId,
Quantity = (int)g.Qty,
SKU = g.SKU
}).ToList()
});
}