VB.NET Enumerable.Max方法代码示例

' Create an array of Nullable Double values.
Dim doubles() As Nullable(Of Double) =
{Nothing, 1.5E+104, 9.0E+103, -2.0E+103}

' Determine the maximum value in the array.
Dim max As Nullable(Of Double) = doubles.Max()

' Display the result.
Console.WriteLine($"The largest number is {max}")

' Create a list of Long values.
Dim longs As New List(Of Long)(New Long() _
                           {4294967296L, 466855135L, 81125L})

' Get the maximum value in the list.
Dim max As Long = longs.Max()

' Display the result.
Console.WriteLine($"The largest number is {max}")

Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Sub MaxEx4()
    ' Create an array of Pet objects.
    Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8},
                     New Pet With {.Name = "Boots", .Age = 4},
                     New Pet With {.Name = "Whiskers", .Age = 1}}

    ' Determine the "maximum" pet by passing a
    ' lambda expression to Max() that sums the pet's age
    ' and name length.
    Dim max As Integer = pets.Max(Function(pet) _
                                  pet.Age + pet.Name.Length)

    ' Display the result.
    Console.WriteLine($"The maximum pet age plus name length is {max}")
End Sub

' This class implements IComparable 
' and has a custom 'CompareTo' implementation.
Class Pet
    Implements IComparable(Of Pet)

    Public Name As String
    Public Age As Integer

    ''' <summary>
    ''' Compares Pet objects by the sum of their age and name length.
    ''' </summary>
    ''' <param name="other">The Pet to compare this Pet to.</param>
    ''' <returns>-1 if this Pet's sum is 'less' than the other Pet,
    ''' 0 if they are equal,
    ''' or 1 if this Pet's sum is 'greater' than the other Pet.</returns>
    Function CompareTo(ByVal other As Pet) As Integer _
    Implements IComparable(Of Pet).CompareTo

        If (other.Age + other.Name.Length > Me.Age + Me.Name.Length) Then
            Return -1
        ElseIf (other.Age + other.Name.Length = Me.Age + Me.Name.Length) Then
            Return 0
        Else
            Return 1
        End If
    End Function
End Class

Sub MaxEx3()
    ' Create an array of Pet objects.
    Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8},
                     New Pet With {.Name = "Boots", .Age = 4},
                     New Pet With {.Name = "Whiskers", .Age = 1}}

    ' Find the "maximum" pet according to the 
    ' custom CompareTo() implementation.
    Dim max As Pet = pets.Max()

    ' Display the result.
    Console.WriteLine($"The 'maximum' animal is {max.Name}")
End Sub