Vb.net Linq-to-Entity框架中的多动态Order-By

SortExpression的输入类似于“field1 true；field2 false；field3 true”

我希望查询具有多个order by字段，实际情况是只应用最后一个order by。我做错了什么

---

工作结果如下所示：

Dim receipts As IQueryable(Of ReceiptEntity) = db.Receipts

'code to filter removed for brevity

Dim sorts() As String = SortExpression.Split(";")

For Each sort As String In sorts
    Dim sortParts() As String = sort.Split(" ")
    If sortParts(1).ToLower = "true" Then
        receipts = receipts.OrderBy(Of ReceiptEntity)(sortParts(0).ToString(), SortDirection.Ascending)
    Else
        receipts = receipts.OrderBy(Of ReceiptEntity)(sortParts(0).ToString(), SortDirection.Descending)
    End If
Next

---

对于第二次和所有后续排序操作，您必须使用

ThenBy

而不是

OrderBy

。

谢谢，您还必须在声明中使用IOrderedQueryable（of T）而不是IQueryable（of T），以获得ThenBy和ThenBy降序。

Dim receipts As IOrderedQueryable(Of ReceiptEntity) = db.Receipts.Include(Function(r) r.LineItems).Include(Function(r) r.Payments)

Dim sorts() As String = SortExpression.Split(";")
Dim sortParts() As String
sortParts = sorts(0).Split(" ")
If sortParts(1).ToLower = "true" Then
    receipts = receipts.OrderBy(sortParts(0).ToString())
Else
    receipts = receipts.OrderByDescending(sortParts(0).ToString())
End If


For Each sort As String In sorts.Skip(1)
    sortParts = sort.Split(" ")
    If sortParts(1).ToLower = "true" Then
        receipts = receipts.ThenBy(sortParts(0).ToString())
    Else
        receipts = receipts.ThenByDescending(sortParts(0).ToString())
    End If
Next