FlagsAttribute Constructor
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Initialiseert een nieuw exemplaar van de FlagsAttribute klasse.
public:
FlagsAttribute();public FlagsAttribute();Public Sub New ()Voorbeelden
In het volgende voorbeeld wordt een PhoneService opsomming gedefinieerd die vormen van communicatie vertegenwoordigt die wordt geleverd door een telefoonbedrijf. Het initialiseert drie variabelen die de service vertegenwoordigen die aan drie verschillende huishoudens wordt geleverd en geeft vervolgens aan welke huishoudens geen service hebben, welke huishoudens alleen een mobiele telefoonservice hebben en welke huishoudens zowel een mobiele telefoon als een vaste service hebben. Ten slotte roept het impliciet de Enum.ToString(String) methode aan om de soorten diensten weer te geven die aan elk huishouden worden geleverd.
using System;
[Flags]
public enum PhoneService
{
None = 0,
LandLine = 1,
Cell = 2,
Fax = 4,
Internet = 8,
Other = 16
}
public class Example
{
public static void Main()
{
// Define three variables representing the types of phone service
// in three households.
var household1 = PhoneService.LandLine | PhoneService.Cell |
PhoneService.Internet;
var household2 = PhoneService.None;
var household3 = PhoneService.Cell | PhoneService.Internet;
// Store the variables in an array for ease of access.
PhoneService[] households = { household1, household2, household3 };
// Which households have no service?
for (int ctr = 0; ctr < households.Length; ctr++)
Console.WriteLine("Household {0} has phone service: {1}",
ctr + 1,
households[ctr] == PhoneService.None ?
"No" : "Yes");
Console.WriteLine();
// Which households have cell phone service?
for (int ctr = 0; ctr < households.Length; ctr++)
Console.WriteLine("Household {0} has cell phone service: {1}",
ctr + 1,
(households[ctr] & PhoneService.Cell) == PhoneService.Cell ?
"Yes" : "No");
Console.WriteLine();
// Which households have cell phones and land lines?
var cellAndLand = PhoneService.Cell | PhoneService.LandLine;
for (int ctr = 0; ctr < households.Length; ctr++)
Console.WriteLine("Household {0} has cell and land line service: {1}",
ctr + 1,
(households[ctr] & cellAndLand) == cellAndLand ?
"Yes" : "No");
Console.WriteLine();
// List all types of service of each household?//
for (int ctr = 0; ctr < households.Length; ctr++)
Console.WriteLine("Household {0} has: {1:G}",
ctr + 1, households[ctr]);
Console.WriteLine();
}
}
// The example displays the following output:
// Household 1 has phone service: Yes
// Household 2 has phone service: No
// Household 3 has phone service: Yes
//
// Household 1 has cell phone service: Yes
// Household 2 has cell phone service: No
// Household 3 has cell phone service: Yes
//
// Household 1 has cell and land line service: Yes
// Household 2 has cell and land line service: No
// Household 3 has cell and land line service: No
//
// Household 1 has: LandLine, Cell, Internet
// Household 2 has: None
// Household 3 has: Cell, Internet
open System
[<Flags>]
type PhoneService =
| None = 0
| LandLine = 1
| Cell = 2
| Fax = 4
| Internet = 8
| Other = 16
// Define three variables representing the types of phone service
// in three households.
let household1 =
PhoneService.LandLine ||| PhoneService.Cell ||| PhoneService.Internet
let household2 =
PhoneService.None
let household3 =
PhoneService.Cell ||| PhoneService.Internet
// Store the variables in a list for ease of access.
let households =
[ household1; household2; household3 ]
// Which households have no service?
for i = 0 to households.Length - 1 do
printfn $"""Household {i + 1} has phone service: {if households[i] = PhoneService.None then "No" else "Yes"}"""
printfn ""
// Which households have cell phone service?
for i = 0 to households.Length - 1 do
printfn $"""Household {i + 1} has cell phone service: {if households[i] &&& PhoneService.Cell = PhoneService.Cell then "Yes" else "No"}"""
printfn ""
// Which households have cell phones and land lines?
let cellAndLand =
PhoneService.Cell ||| PhoneService.LandLine
for i = 0 to households.Length - 1 do
printfn $"""Household {i + 1} has cell and land line service: {if households[i] &&& cellAndLand = cellAndLand then "Yes" else "No"}"""
printfn ""
// List all types of service of each household?//
for i = 0 to households.Length - 1 do
printfn $"Household {i + 1} has: {households[i]:G}"
// The example displays the following output:
// Household 1 has phone service: Yes
// Household 2 has phone service: No
// Household 3 has phone service: Yes
//
// Household 1 has cell phone service: Yes
// Household 2 has cell phone service: No
// Household 3 has cell phone service: Yes
//
// Household 1 has cell and land line service: Yes
// Household 2 has cell and land line service: No
// Household 3 has cell and land line service: No
//
// Household 1 has: LandLine, Cell, Internet
// Household 2 has: None
// Household 3 has: Cell, Internet
<Flags()>
Public Enum PhoneService As Integer
None = 0
LandLine = 1
Cell = 2
Fax = 4
Internet = 8
Other = 16
End Enum
Module Example
Public Sub Main()
' Define three variables representing the types of phone service
' in three households.
Dim household1 As PhoneService = PhoneService.LandLine Or
PhoneService.Cell Or
PhoneService.Internet
Dim household2 As PhoneService = PhoneService.None
Dim household3 As PhoneService = PhoneService.Cell Or
PhoneService.Internet
' Store the variables in an array for ease of access.
Dim households() As PhoneService = { household1, household2,
household3 }
' Which households have no service?
For ctr As Integer = 0 To households.Length - 1
Console.WriteLine("Household {0} has phone service: {1}",
ctr + 1,
If(households(ctr) = PhoneService.None,
"No", "Yes"))
Next
Console.WriteLine()
' Which households have cell phone service?
For ctr As Integer = 0 To households.Length - 1
Console.WriteLine("Household {0} has cell phone service: {1}",
ctr + 1,
If((households(ctr) And PhoneService.Cell) = PhoneService.Cell,
"Yes", "No"))
Next
Console.WriteLine()
' Which households have cell phones and land lines?
Dim cellAndLand As PhoneService = PhoneService.Cell Or PhoneService.LandLine
For ctr As Integer = 0 To households.Length - 1
Console.WriteLine("Household {0} has cell and land line service: {1}",
ctr + 1,
If((households(ctr) And cellAndLand) = cellAndLand,
"Yes", "No"))
Next
Console.WriteLine()
' List all types of service of each household?'
For ctr As Integer = 0 To households.Length - 1
Console.WriteLine("Household {0} has: {1:G}",
ctr + 1, households(ctr))
Next
Console.WriteLine()
End Sub
End Module
' The example displays the following output:
' Household 1 has phone service: Yes
' Household 2 has phone service: No
' Household 3 has phone service: Yes
'
' Household 1 has cell phone service: Yes
' Household 2 has cell phone service: No
' Household 3 has cell phone service: Yes
'
' Household 1 has cell and land line service: Yes
' Household 2 has cell and land line service: No
' Household 3 has cell and land line service: No
'
' Household 1 has: LandLine, Cell, Internet
' Household 2 has: None
' Household 3 has: Cell, Internet
Het volgende voorbeeld illustreert het gebruik van het FlagsAttribute kenmerk en toont het effect op de ToString methode om FlagsAttribute te gebruiken in een Enum declaratie.
using System;
class Example
{
// Define an Enum without FlagsAttribute.
enum SingleHue : short
{
None = 0,
Black = 1,
Red = 2,
Green = 4,
Blue = 8
};
// Define an Enum with FlagsAttribute.
[Flags]
enum MultiHue : short
{
None = 0,
Black = 1,
Red = 2,
Green = 4,
Blue = 8
};
static void Main( )
{
// Display all possible combinations of values.
Console.WriteLine(
"All possible combinations of values without FlagsAttribute:");
for(int val = 0; val <= 16; val++ )
Console.WriteLine( "{0,3} - {1:G}", val, (SingleHue)val);
// Display all combinations of values, and invalid values.
Console.WriteLine(
"\nAll possible combinations of values with FlagsAttribute:");
for( int val = 0; val <= 16; val++ )
Console.WriteLine( "{0,3} - {1:G}", val, (MultiHue)val);
}
}
// The example displays the following output:
// All possible combinations of values without FlagsAttribute:
// 0 - None
// 1 - Black
// 2 - Red
// 3 - 3
// 4 - Green
// 5 - 5
// 6 - 6
// 7 - 7
// 8 - Blue
// 9 - 9
// 10 - 10
// 11 - 11
// 12 - 12
// 13 - 13
// 14 - 14
// 15 - 15
// 16 - 16
//
// All possible combinations of values with FlagsAttribute:
// 0 - None
// 1 - Black
// 2 - Red
// 3 - Black, Red
// 4 - Green
// 5 - Black, Green
// 6 - Red, Green
// 7 - Black, Red, Green
// 8 - Blue
// 9 - Black, Blue
// 10 - Red, Blue
// 11 - Black, Red, Blue
// 12 - Green, Blue
// 13 - Black, Green, Blue
// 14 - Red, Green, Blue
// 15 - Black, Red, Green, Blue
// 16 - 16
open System
// Define an Enum without FlagsAttribute.
type SingleHue =
| None = 0
| Black = 1
| Red = 2
| Green = 4
| Blue = 8
// Define an Enum with FlagsAttribute.
[<Flags>]
type MultiHue =
| None = 0
| Black = 1
| Red = 2
| Green = 4
| Blue = 8
// Display all possible combinations of values.
printfn "All possible combinations of values without FlagsAttribute:"
for i = 0 to 16 do
printfn $"{i,3} - {enum<SingleHue> i:G}"
// Display all combinations of values, and invalid values.
printfn "\nAll possible combinations of values with FlagsAttribute:"
for i = 0 to 16 do
printfn $"{i,3} - {enum<MultiHue> i:G}"
// The example displays the following output:
// All possible combinations of values without FlagsAttribute:
// 0 - None
// 1 - Black
// 2 - Red
// 3 - 3
// 4 - Green
// 5 - 5
// 6 - 6
// 7 - 7
// 8 - Blue
// 9 - 9
// 10 - 10
// 11 - 11
// 12 - 12
// 13 - 13
// 14 - 14
// 15 - 15
// 16 - 16
//
// All possible combinations of values with FlagsAttribute:
// 0 - None
// 1 - Black
// 2 - Red
// 3 - Black, Red
// 4 - Green
// 5 - Black, Green
// 6 - Red, Green
// 7 - Black, Red, Green
// 8 - Blue
// 9 - Black, Blue
// 10 - Red, Blue
// 11 - Black, Red, Blue
// 12 - Green, Blue
// 13 - Black, Green, Blue
// 14 - Red, Green, Blue
// 15 - Black, Red, Green, Blue
// 16 - 16
Module Example
' Define an Enum without FlagsAttribute.
Enum SingleHue As Short
None = 0
Black = 1
Red = 2
Green = 4
Blue = 8
End Enum
' Define an Enum with FlagsAttribute.
<Flags()>
Enum MultiHue As Short
None = 0
Black = 1
Red = 2
Green = 4
Blue = 8
End Enum
Sub Main()
' Display all possible combinations of values.
Console.WriteLine(
"All possible combinations of values without FlagsAttribute:")
For val As Integer = 0 To 16
Console.WriteLine("{0,3} - {1:G}", val, CType(val, SingleHue))
Next
Console.WriteLine()
' Display all combinations of values, and invalid values.
Console.WriteLine(
"All possible combinations of values with FlagsAttribute:")
For val As Integer = 0 To 16
Console.WriteLine( "{0,3} - {1:G}", val, CType(val, MultiHue))
Next
End Sub
End Module
' The example displays the following output:
' All possible combinations of values without FlagsAttribute:
' 0 - None
' 1 - Black
' 2 - Red
' 3 - 3
' 4 - Green
' 5 - 5
' 6 - 6
' 7 - 7
' 8 - Blue
' 9 - 9
' 10 - 10
' 11 - 11
' 12 - 12
' 13 - 13
' 14 - 14
' 15 - 15
' 16 - 16
'
' All possible combinations of values with FlagsAttribute:
' 0 - None
' 1 - Black
' 2 - Red
' 3 - Black, Red
' 4 - Green
' 5 - Black, Green
' 6 - Red, Green
' 7 - Black, Red, Green
' 8 - Blue
' 9 - Black, Blue
' 10 - Red, Blue
' 11 - Black, Red, Blue
' 12 - Green, Blue
' 13 - Black, Green, Blue
' 14 - Red, Green, Blue
' 15 - Black, Red, Green, Blue
' 16 - 16