Question

我正在使用VB.Net并具有以下LINQ查询...

Dim ACFTTail5 = (From tailcounts In db.TailCounts _
                 Where tailcounts.Model = "UH-60A" _
                 Group tailcounts By _
                 tailcounts.Tail, tailcounts.Model _
                 Into g = Group Order By Tail _
                 Select Tail, rdf = CStr(g.Sum(Function(p) _ p.TailCount))).ToArray

我正在尝试获得如下所示的二维数组..

    ACFTTail5 (0)(0) “Tail-a”
    ACFTTail5 (0)(1) “RDF-a”
    ACFTTail5 (1)(0) “Tail-b”
    ACFTTail5 (1)(1) “RDF-b”
    ACFTTail5 (2)(0) “Tail-c”
    ACFTTail5 (2)(1) “RDF-c”

ETC ..

我试过......

    Dim ACFTTail5(,) As String

    ACFTTail5 = (From tailcounts In db.TailCounts _
                 Where tailcounts.Model = "UH-60A" _
                 Group tailcounts By _
                 tailcounts.Tail, tailcounts.Model _
                 Into g = Group Order By Tail _
                 Select Tail, rdf = CStr(g.Sum(Function(p) p.TailCount)))

但是得到以下错误......

“无法转换类型为'System.Data.Linq.DataQuery 1[VB$AnonymousType_4的对象2 [System.String，System.String]]'来键入'System.String [，]'。”

我们将非常感谢任何建议......

由于

Answer 1

如果您不太关心强制它进入二维数组，您可以只允许编译器分配匿名IQueryable类型并将其用于迭代：

Dim ACFTTail5 = (From tailcounts In db.TailCounts _
             Where tailcounts.Model = "UH-60A" _
             Group tailcounts By _
             tailcounts.Tail, tailcounts.Model _
             Into g = Group Order By Tail _
             Select Tail, rdf = CStr(g.Sum(Function(p) p.TailCount)))

然后您可以使用For each迭代器来循环浏览所需的任何内容。

修改
我没有测试过这个小小的片段，但你应该可以使用List

Dim ACFTTail5 as List(Of String()) ACFTTail5 = new List(Of String())(From tailcounts In db.TailCounts _ Where tailcounts.Model = "UH-60A" _ Group tailcounts By _ tailcounts.Tail, tailcounts.Model _ Into g = Group Order By Tail _ Select new String() { Tail, rdf = CStr(g.Sum(Function(p) p.TailCount)) }) Dim ACFTTail5_2d_Array as String(,) = ACFTTail5.ToArray()

我在这里使用的关键是直接将它选择到一个新类（在本例中为字符串数组），并将其保存在专门用于字符串数组的List中。然后你应该能够将它发送到字符串数组的字符串数组。

从LINQ查询加载二维数组？

1 个答案: