Question

我有一个项目集合，每个项目都有一系列关系。我有一个项目列表，项目可以与之关系。

我可以找到所有具有特定关系的项目，但我现在想找到所有与我的任何组没有关系的项目。

我可以通过这样做找到与任何组有关系的项目：

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
                 Where item.Relationships.Any(Function(r) groupIds.Contains(r.TargetID)) _
                 Select item).ToList

如何查找与任何群组没有关系的所有项目？

Answer 1

您是否尝试过否定Contains方法的结果？

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
                 Where item.Relationships.Any(Function(r) Not groupIds.Contains(r.TargetID)) _
                 Select item).ToList

Answer 2

我不记得VB那么好，但简单的“不”应该有用。

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
             Where Not item.Relationships.Any(Function(r) groupIds.Contains(r.TargetID)) _
             Select item).ToList

Answer 3

如果您正在生成haveGroup集合，那么您可以执行以下操作：

Dim groupIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList

Dim haveGroup = (From item In items _
    Where item.Relationships.Any(Function(r) groupIds.Contains(r.TargetID)) _
    Select item).ToList

Dim haveNotGroup = items.Except(haveGroup).ToList

Answer 4

Dim notHasGroup = items.Except(haveGroup)

Answer 5

Dim listIds as List(of Integer) = (From g In cmdbGroups Select g.ID).ToList
Dim haveGroup = (From item In items _
    Where Not listIds.Contains(item.ID) 
    Select item.ID).ToList

LINQ to Objects - 不包含？

5 个答案: