Enum.Equals(Object) Metod

Definition

Namnområde:

System

Sammansättning:

mscorlib.dll

Returnerar ett värde som anger om den här instansen är lika med ett angivet objekt.

public:
 override bool Equals(System::Object ^ obj);

public override bool Equals(object obj);

override this.Equals : obj -> bool

Public Overrides Function Equals (obj As Object) As Boolean

Parametrar

obj

Object

Ett objekt att jämföra med den här instansen, eller null.

Returer

Boolean

true om obj är ett uppräkningsvärde av samma typ och med samma underliggande värde som den här instansen, falseannars .

Exempel

I följande exempel visas hur metoden används Equals .

using System;

public class EqualsTest {
    enum Colors { Red, Green, Blue, Yellow };
    enum Mammals { Cat, Dog, Horse, Dolphin };

    public static void Main() {
        Mammals myPet = Mammals.Cat;
        Colors myColor = Colors.Red;
        Mammals yourPet = Mammals.Dog;
        Colors yourColor = Colors.Red;

        Console.WriteLine("My favorite animal is a {0}", myPet);
        Console.WriteLine("Your favorite animal is a {0}", yourPet);
        Console.WriteLine("Do we like the same animal? {0}", myPet.Equals(yourPet) ? "Yes" : "No");

        Console.WriteLine();
        Console.WriteLine("My favorite color is {0}", myColor);
        Console.WriteLine("Your favorite color is {0}", yourColor);
        Console.WriteLine("Do we like the same color? {0}", myColor.Equals(yourColor) ? "Yes" : "No");

        Console.WriteLine();
        Console.WriteLine("The value of my color ({0}) is {1}", myColor, Enum.Format(typeof(Colors), myColor, "d"));
        Console.WriteLine("The value of my pet (a {0}) is {1}", myPet, Enum.Format(typeof(Mammals), myPet, "d"));
        Console.WriteLine("Even though they have the same value, are they equal? {0}",
                    myColor.Equals(myPet) ? "Yes" : "No");
    }
}
// The example displays the following output:
//    My favorite animal is a Cat
//    Your favorite animal is a Dog
//    Do we like the same animal? No
//
//    My favorite color is Red
//    Your favorite color is Red
//    Do we like the same color? Yes
//
//    The value of my color (Red) is 0
//    The value of my pet (a Cat) is 0
//    Even though they have the same value, are they equal? No

open System

type Colors =
    | Red = 0
    | Green = 1
    | Blue = 2
    | Yellow = 3

type Mammals =
    | Cat = 0
    | Dog = 1
    | Horse = 2
    | Dolphin = 3

let myPet = Mammals.Cat
let myColor = Colors.Red
let yourPet = Mammals.Dog
let yourColor = Colors.Red

printfn 
    $"""My favorite animal is a {myPet}
Your favorite animal is a {yourPet}
Do we like the same animal? {if myPet.Equals yourPet then "Yes" else "No"}

My favorite color is {myColor}
Your favorite color is {yourColor}
Do we like the same color? {if myColor.Equals yourColor then "Yes" else "No"}

The value of my color ({myColor}) is {Enum.Format(typeof<Colors>, myColor, "d")}
The value of my pet (a {myPet}) is {Enum.Format(typeof<Mammals>, myPet, "d")}
Even though they have the same value, are they equal? {if myColor.Equals myPet then "Yes" else "No"}"""

// The example displays the following output:
//    My favorite animal is a Cat
//    Your favorite animal is a Dog
//    Do we like the same animal? No
//
//    My favorite color is Red
//    Your favorite color is Red
//    Do we like the same color? Yes
//
//    The value of my color (Red) is 0
//    The value of my pet (a Cat) is 0
//    Even though they have the same value, are they equal? No

Public Enum SledDog As Integer
   Unknown=0
   AlaskanMalamute=1
   Malamute=1
   Husky=2
   SiberianHusky=2
End Enum

Public Enum WorkDog As Integer
   Unknown=0
   Newfoundland=1
   GreatPyrennes=2
End Enum

Module Example
   Public Sub Main()
      Dim dog1 As SledDog = SledDog.Malamute
      Dim dog2 As SledDog = SledDog.AlaskanMalamute
      Dim dog3 As WorkDog = WorkDog.Newfoundland
      
      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}", 
                        dog1, dog2, dog1.Equals(dog2))
      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog3, dog1.Equals(dog3))
   End Sub
End Module
' The example displays the following output:
'       Malamute (1) = Malamute (1): True
'       Malamute (1) = Newfoundland (1): False

I följande exempel definieras två uppräkningstyper SledDog och WorkDog. Uppräkningen SledDog har två medlemmar SledDog.AlaskanMalamute och SledDog.Malamute, som har samma underliggande värde. Anropet Equals till metoden anger att dessa värden är lika med eftersom deras underliggande värden är desamma. Medlemmarna SledDog.Malamute och WorkDog.Newfoundland har samma underliggande värde, även om de representerar olika uppräkningstyper. Ett anrop till Equals metoden anger att dessa värden inte är lika med.

using System;

public enum SledDog { Unknown=0, AlaskanMalamute=1, Malamute=1,
                      Husky=2, SiberianHusky=2 };

public enum WorkDog { Unknown=0, Newfoundland=1, GreatPyrennes=2 };

public class Example
{
   public static void Main()
   {
      SledDog dog1 = SledDog.Malamute;
      SledDog dog2 = SledDog.AlaskanMalamute;
      WorkDog dog3 = WorkDog.Newfoundland;

      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog2, dog1.Equals(dog2));
      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog3, dog1.Equals(dog3));
   }
}
// The example displays the following output:
//       Malamute (1) = Malamute (1): True
//       Malamute (1) = Newfoundland (1): False

type SledDog =
    | Unknown = 0
    | AlaskanMalamute = 1
    | Malamute = 1
    | Husky = 2
    | SiberianHusky = 2

type WorkDog =
    | Unknown = 0
    | Newfoundland = 1
    | GreatPyrennes = 2

let dog1 = SledDog.Malamute
let dog2 = SledDog.AlaskanMalamute
let dog3 = WorkDog.Newfoundland

printfn $"{dog1:F} ({dog1:D}) = {dog2:F} ({dog2:D}): {dog1.Equals dog2}"
printfn $"{dog1:F} ({dog1:D}) = {dog3:F} ({dog3:D}): {dog1.Equals dog3}"
// The example displays the following output:
//       Malamute (1) = Malamute (1): True
//       Malamute (1) = Newfoundland (1): False

Public Enum SledDog As Integer
   Unknown=0
   AlaskanMalamute=1
   Malamute=1
   Husky=2
   SiberianHusky=2
End Enum

Public Enum WorkDog As Integer
   Unknown=0
   Newfoundland=1
   GreatPyrennes=2
End Enum

Module Example
   Public Sub Main()
      Dim dog1 As SledDog = SledDog.Malamute
      Dim dog2 As SledDog = SledDog.AlaskanMalamute
      Dim dog3 As WorkDog = WorkDog.Newfoundland

      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog2, dog1.Equals(dog2))
      Console.WriteLine("{0:F} ({0:D}) = {1:F} ({1:D}): {2}",
                        dog1, dog3, dog1.Equals(dog3))
   End Sub
End Module

' The example displays the following output:
'       Malamute (1) = Malamute (1): True
'       Malamute (1) = Newfoundland (1): False

Kommentarer

Metoden Enum.Equals(Object) åsidosätter ValueType.Equals(Object) för att definiera hur uppräkningsmedlemmar utvärderas för likhet.

Se även

• CompareTo(Object)