Enum.Equals(Object) Enum.Equals(Object) Enum.Equals(Object) Enum.Equals(Object) Method

定义

返回一个值,该值指示此实例是否等于指定的对象。Returns a value indicating whether this instance is equal to a specified object.

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

参数

obj
Object Object Object Object

与此实例进行比较的对象,或为 nullAn object to compare with this instance, or null.

返回

如果枚举值 obj 的类型和基础值与此实例相同,则为 true;否则为 falsetrue if obj is an enumeration value of the same type and with the same underlying value as this instance; otherwise, false.

示例

下面的示例演示 Equals 方法的用法。The following example illustrates the use of the Equals method.

using namespace System;
public enum class Colors
{
   Red, Green, Blue, Yellow
};

public enum class Mammals
{
   Cat, Dog, Horse, Dolphin
};

int 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 ) ? (String^)"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 ) ? (String^)"Yes" : "No" );
   Console::WriteLine();
   Console::WriteLine(  "The value of my color ({0}) is {1}", myColor, Enum::Format( Colors::typeid, myColor,  "d" ) );
   Console::WriteLine(  "The value of my pet (a {0}) is {1}", myPet, Enum::Format( Mammals::typeid, myPet,  "d" ) );
   Console::WriteLine(  "Even though they have the same value, are they equal? {0}", myColor.Equals( myPet ) ? (String^)"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
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
Public Class EqualsTest
    Enum Colors
        Red
        Green
        Blue
        Yellow
    End Enum 
    
    Enum Mammals
        Cat
        Dog
        Horse
        Dolphin
    End Enum 
    
    Public Shared Sub Main()
        Dim myPet As Mammals = Mammals.Cat
        Dim myColor As Colors = Colors.Red
        Dim yourPet As Mammals = Mammals.Dog
        Dim yourColor As Colors = Colors.Red
        Dim output as string
        
        Console.WriteLine("My favorite animal is a {0}", myPet)
        Console.WriteLine("Your favorite animal is a {0}", yourPet)
        If myPet.Equals(yourPet) Then output = "Yes" Else output = "No"
        Console.WriteLine("Do we like the same animal? {0}", output)
        
        Console.WriteLine()
        Console.WriteLine("My favorite color is {0}", myColor)
        Console.WriteLine("Your favorite color is {0}", yourColor)
        If myColor.Equals(yourColor) Then output = "Yes" Else output = "No"
        Console.WriteLine("Do we like the same color? {0}", output)
        
        Console.WriteLine()
        Console.WriteLine("The value of my color ({0}) is {1}", myColor, [Enum].Format(GetType(Colors), myColor, "d"))
        Console.WriteLine("The value of my pet (a {0}) is {1}", myPet, [Enum].Format(GetType(Mammals), myPet, "d"))
        Console.WriteLine("Even though they have the same value, are they equal? {0}", 
                          If(myColor.Equals(myPet), "Yes", "No"))
    End Sub 
End Class 
' 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

下面的示例定义了两个枚举SledDog类型WorkDog:和。The following example defines two enumeration types, SledDog and WorkDog. 枚举具有两个具有相同SledDog.AlaskanMalamute基础SledDog.Malamute值的成员(和)。 SledDogThe SledDog enumeration has two members, SledDog.AlaskanMalamute and SledDog.Malamute, that have the same underlying value. Equals方法的调用指示这些值相等,因为它们的基础值是相同的。The call to the Equals method indicates that these values are equal because their underlying values are the same. SledDog.MalamuteWorkDog.Newfoundland成员具有相同的基础值,尽管它们表示不同的枚举类型。The SledDog.Malamute and WorkDog.Newfoundland members have the same underlying value, although they represent different enumeration types. Equals方法的调用指示这些值不相等。A call to the Equals method indicates that these values are not equal.

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
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

注解

方法重写ValueType.Equals(Object)以定义如何计算枚举成员的相等性。 Enum.Equals(Object)The Enum.Equals(Object) method overrides ValueType.Equals(Object) to define how enumeration members are evaluated for equality.

适用于

另请参阅