LINQ量词操作

量词操作符

这些操作符返回一个布尔值，即真或当一个序列中的部分或全部元素满足特定条件的假。

All示例 - All(Tsource)扩展方法

VB

Module Module1

  Sub Main()

     Dim barley As New Pet With {.Name = "Barley", .Age = 4}
     Dim boots As New Pet With {.Name = "Boots", .Age = 1}
     Dim whiskers As New Pet With {.Name = "Whiskers", .Age = 6}
     Dim bluemoon As New Pet With {.Name = "Blue Moon", .Age = 9}
     Dim daisy As New Pet With {.Name = "Daisy", .Age = 3}

     Dim charlotte As New Person With {.Name = "Charlotte", .Pets = New Pet() {barley, boots}}
     Dim arlene As New Person With {.Name = "Arlene", .Pets = New Pet() {whiskers}}
     Dim rui As New Person With {.Name = "Rui", .Pets = New Pet() {bluemoon, daisy}}

     Dim people As New System.Collections.Generic.List(Of Person)(New Person() {charlotte, arlene, rui})

     Dim query = From pers In people
                 Where (Aggregate pt In pers.Pets Into All(pt.Age > 2))
                 Select pers.Name

     For Each e In query
        Console.WriteLine("Name = {0}", e)
     Next

     Console.WriteLine(vbLf & "Press any key to continue.")
     Console.ReadKey()
  End Sub

  Class Person
     Public Property Name As String
     Public Property Pets As Pet()
  End Class

  Class Pet
     Public Property Name As String
     Public Property Age As Integer
  End Class
End Module

当在VB上述代码被编译和执行时，它产生了以下结果：

Arlene 
Rui 

Press any key to continue.

Any例子- 扩展方法

VB

Module Module1

  Sub Main()

     Dim barley As New Pet With {.Name = "Barley", .Age = 4}
     Dim boots As New Pet With {.Name = "Boots", .Age = 1}
     Dim whiskers As New Pet With {.Name = "Whiskers", .Age = 6}
     Dim bluemoon As New Pet With {.Name = "Blue Moon", .Age = 9}
     Dim daisy As New Pet With {.Name = "Daisy", .Age = 3}

     Dim charlotte As New Person With {.Name = "Charlotte", .Pets = New Pet() {barley, boots}}
     Dim arlene As New Person With {.Name = "Arlene", .Pets = New Pet() {whiskers}}
     Dim rui As New Person With {.Name = "Rui", .Pets = New Pet() {bluemoon, daisy}}

     Dim people As New System.Collections.Generic.List(Of Person)(New Person() {charlotte, arlene, rui})

     Dim query = From pers In people
                 Where (Aggregate pt In pers.Pets Into Any(pt.Age > 7))
                 Select pers.Name

     For Each e In query
        Console.WriteLine("Name = {0}", e)
     Next

     Console.WriteLine(vbLf & "Press any key to continue.")
     Console.ReadKey()
  End Sub

  Class Person
     Public Property Name As String
     Public Property Pets As Pet()
  End Class

  Class Pet
     Public Property Name As String
     Public Property Age As Integer
  End Class
End Module

当在VB上述代码被编译和执行时，它产生了以下结果：

Rui

Press any key to continue.