VB.Net Tutorial/Data Type/Enum

Материал из VB Эксперт
Версия от 12:54, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

Assign value to Enum elements

Public Enum AccessLevel
    Clerk = 10
    Supervisor
    Administrator = -1
End Enum

public class Test
   public Shared Sub Main
    Dim m_AccessLevel As AccessLevel
    m_AccessLevel = AccessLevel.Supervisor
    
   End Sub
End class

Assign value to only one Enum element

Public Enum AccessLevel
    Clerk
    Supervisor
    Administrator
    User = 0
    Manager
    SysAdmin
    Superuser = SysAdmin
End Enum

public class Test
   public Shared Sub Main
    Dim m_AccessLevel As AccessLevel
    m_AccessLevel = AccessLevel.Supervisor
    
   End Sub
End class

Cast Integer to Enum value

Public Enum AccessLevel
    Clerk
    Supervisor
    Administrator
    User = 0
    Manager
    SysAdmin
    Superuser = SysAdmin
End Enum

public class Test
   public Shared Sub Main
        Dim m_AccessLevel As AccessLevel
        
        Dim integer_value As Integer = 1
        m_AccessLevel = CType(integer_value, AccessLevel)
        Dim access_level As AccessLevel = AccessLevel.Clerk
        Console.WriteLine(access_level.ToString())
    
   End Sub
End class
Clerk

Compare Enum element using logic operator

Public Enum workDays
        Saturday
        Sunday = 0
        Monday
        Tuesday
        Wednesday
        Thursday
        Friday
        invalid = -1
    End Enum
        
Public Class Tester
    Public Shared Sub Main
        Dim MyDay As WorkDays
        MyDay = WorkDays.Saturday
        If MyDay < workDays.FriDay Then
            Console.WriteLine("It"s the weekend.Invalid work day!")
        End If
    End Sub
End Class
It"s the weekend.Invalid work day!

Convert Enum to Integer

Module Module1
    Enum Temperatures
       A = 0
       B = 32
       C = 60
       D = 72
       E = 212
    End Enum 
    Sub Main( )
       System.Console.WriteLine("B: {0}",CInt(Temperatures.B))
       System.Console.WriteLine("E: {0}", CInt(Temperatures.E))
    End Sub
 End Module
B: 32
E: 212

Declare Enum variable

Public Enum AccessLevel
    Clerk
    Supervisor
    Administrator
End Enum

public class Test
   public Shared Sub Main
    Dim m_AccessLevel As AccessLevel
    m_AccessLevel = AccessLevel.Supervisor
    
   End Sub
End class

Define and use Enum as Integer

Option Strict On
<Flags> Public Enum MyValues As Integer
   AA = 1
   BB = 2
   CC = 4
   DD = 8
End Enum
Public Module modMain
   Public Sub Main()
      Dim Computer1 As MyValues = MyValues.AA Or MyValues.BB
      Console.WriteLine(Computer1.ToString())
   End Sub
End Module
AA, BB

Define Enum and assign value

Module Module1
    Enum Temperatures
       A = 0
       B = 32
       C = 60
       D = 72
       E = 212
    End Enum 
    Sub Main( )
       System.Console.WriteLine("B: {0}",Temperatures.B)
       System.Console.WriteLine("E: {0}",Temperatures.E)
    End Sub
 End Module
B: B
E: E

Enum value duplication

Public Enum AccessLevel
    Level1
    Level2
    Level3
    AliasLevel1 = Level1
    AliasLevel2 = Level2
    AliasLevel3 = Level3
    AliasLevel4 = Level3
End Enum
public class Test
   public Shared Sub Main
        Dim access_level As AccessLevel = AccessLevel.Level1
        Console.WriteLine(access_level.ToString())
        Console.WriteLine(AccessLevel.Level1.ToString())
        Console.WriteLine(AccessLevel.Level2.ToString())
        Console.WriteLine(AccessLevel.Level3.ToString())
   End Sub
End class
Level1
Level1
Level2
AliasLevel3